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Touch Feel and Appearance Characteristics of Automotive Door Armrest Materials | This paper presents results of a five phase study conducted to evaluate touch feel and appearance of door armrest materials. Seven different production door armrests with different material characteristics such as softness, smoothness, compressibility, texture, etc. were evaluated. In the first phase, the subjects seated in a vehicle buck in their preferred seating position with the armrests adjusted at their preferred heights, provided ratings on a number of touch feel and appearance of the door armrest materials using 5-point semantic differential scales. In the second phase, the armrests were presented to each subject in all possible pairs and they were asked to select preferred armrest material in each pair. In the third phase, pressures in the armrest contact area were measured in three armrest usage postures, namely: i) lower arm supported on the armrest (not holding the steering wheel), ii) elbow resting on the armrest while grasping the steering wheel, and iii) the subject attempting to reposition in the seat while pushing his/her elbow against the armrest (maximum possible pressure). Pressure measurements (peak, average and contact area) were made for 12 subjects using XSENSOR pressure mapping digital mat. The fourth phase involved evaluation of all the touch characteristics in the dark to eliminate any visual influence. And finally, in the fifth phase, the subjects were asked to rank order important characteristics of the armrest materials. Some results of the studies are: a) The 95% confidence intervals of 5-point ratings discriminated different armrests on each characteristic defined by adjective pairs such as Smooth/Rough, Compressive/Non-Compressive, Plain/Textured, Fine/Coarse, etc. b) Correlation analyses revealed a number of relationships between the variables (e.g. Soft/Hard ratings were highly correlated with Compressive/Non-Compressive ratings, Cheap/Expensive ratings were correlated to Fake/Genuine, and Pleasing/Non-Pleasing ratings; but Texture/Plain were uncorrelated with Cheap/Expensive or Fake/Genuine ratings). c) The pressure measurements data showed: i) Under normal forearm resting posture the average and peak pressures ranged between 3 to 10 psi and 4 to 25 psi, respectively. ii) With the elbow resting on the armrest while holding on the steering wheel, the average and peak pressures ranged between 4 to 19 psi and 5 to 40 psi, respectively. iii) While repositioning in the seat, the average and peak pressures ranged between 5 to 17 psi and 10 to 40 psi, respectively. d) Evaluations of touch feel conducted in the dark, differed from those from those conducted using both touch and visual sensory cues. |
Measuring the Pitch of Door Closing Sounds - The Sound Quality Issue of Door ?쏷hump??"This paper discusses a partially completed project that was begun shortly before an unexpected retirement opportunity appeared that limits the possibilities for follow-up work. The project was to investigate the pitch of door closing ?쐔hump.??The impetus for the investigation was a paper by Gardner and Magnasco. Their paper described an instantaneous frequency decomposition method that they used in the study of bird song and human speech. Bird song or speech may not seem to be closely linked to measuring door closing thump but the speed with which the frequencies in door closing sounds change is not that different from the speed of frequency change in bird song or speech. Two questions that immediately arise are can Gardner and Magnasco's technique resolve the low frequency components that occur in door closing sounds and | if so |
Optimization of Mirror Angle for Front Window Buffeting and Wind Noise Using Experimental Methods | Door mirrors have a major impact on wind noise observed at the driver's ear. The mirror distance and angle with respect to the front side glass will influence the front window buffeting characteristics of the vehicle as well. Optimizing the mirror angle to minimize or eliminate buffeting while maintaining acceptable wind noise performance can provide additional customer satisfaction. Changes to the mirror angle were investigated experimentally for both wind noise and buffeting effects. Experimental vehicle interior noise and buffeting data was taken at multiple yaw angles and wind speeds using a full scale aero acoustic wind tunnel. In addition, experimental wind noise attributes for the different mirror angles was also used to determine the optimal angle. The resulting angle measurement will be used as a best practice mirror angle for optimal wind noise and front window buffeting performance on future vehicle programs. |
Capacitive Sensing in an Automotive Environment | Capacitance sensing in motor vehicles allows for protection in power windows, sunroofs, liftgates and sliding doors. It also provides greater design freedom of operator interfaces that include switch entry and fingerprint sensing. Fingerprint sensing adds new levels of security for the access and starting of a vehicle thus allowing for the elimination of keys. This paper describes the design and operation of various systems that could employ capacitive sensing technology including keyless entry, operator controls, and safety related sensing. Also discussed are vehicle installation, safety enhancement, and ergonomic benefits. |
Rapid Prototyping Applied to Parts Used in Static Tests of Racks for Packing and Transporting Automobile Parts | This work was motivated by the specific needs of a materials flow and packing planning sector (PFME), within a manufacturing engineering department of a vehicle assembly company in Brazil. In this sector, there is a growing need to obtain prototype parts in the shortest time and at the lowest cost possible in order to carry out static prototype tests of the special packing and transportation racks used in this company, since these racks need to be ready to assist the preparation phase of the series production of the vehicle. The objective of this work is to survey the academic theory and the existing literature in order to find an application proposal of rapid prototyping (RP) techniques to make the parts used in the rack tests, thus reducing time and acquisition costs. For that purpose, some limiting conditions were considered: first, the application of the RP technique is limited to the external parts of the vehicle, such as doors, front and back hoods, and fenders; second, the consulted suppliers should be available in the domestic market. Finally, a proposal of work systematics for the assembly company is presented. |
Design of Door Latching and Locking Systems for Crashworthiness | Several sub-systems in a vehicle contribute to vehicle crashworthiness. One such system is the door latch and locking system. Correct functioning of this system is critical for facilitating occupant evacuation and preventing occupant ejection during crashes. Special care needs to be taken during vehicle safety development to achieve the desired intent. In crashes, it is observed that door opening or locking mainly occurs on account of inertial loads and deformation of the door structure. This paper studies the possible failure modes and their causes. Some likely solutions have also been discussed with a case study. |
A Case Study About Side Door Closing Sound Quality | Side Door Closing Sound Quality is one of the first impressions a potential customer has about a vehicle. It can enhance an impression of robust and high quality vehicle. This paper is a study of Side Door Closing Sound of a specific vehicle model. The main objective is to understand how Door Closing Sound Quality varies over several vehicles samples and how to improve the design and/or production process in order to achieve better Sound Quality. Two vehicles (same model) with distinct performance have been chosen among several samples. Both have been evaluated and the physical differences are weighted to realize what really matter for Door Closing Sound Quality. |
Investing Factors Affecting Door Slam Noise of SUV and Improved Performance by DFSS Approach | Recent development in automobile industries has seen increased customer attention for good door slamming noise. One of the constituent which plays major role in building brand image of vehicle in terms of NVH performance is door slam noise quality. Hence it is very desirable to understand how different door elements radiate sound during a door-closing event and how to optimize a door structure to achieve specific sound target in order to ensure the door closing noise quality, NVH engineers needed to look at contributions from different door subsystems. The use of statistical tools like Six Sigma can further help them to ensure the consistency in results. This paper explains the systematic approach used to characterize different element of door which contributes to the overall door slam noise quality through QFD (Quality Function Deployment) and contribution analysis. The different mechanisms contributing to door slam noise were studied. NVH characteristics (Acoustic transfer Function and Point Mobility) of the door structure and mounting locations were captured for correlating with the time - frequency spectrum of door slam event. Wavelet analysis was performed on door impact event to determine the critical frequency band contribute to noise. DOE (Design of Experiments) was constructed based on the analysis of results. Prototype modifications were conducted, the results of which are discussed in the paper together with their relative importance to work improvement in door closing noise. Finally the design intent solutions were developed together with component supplier and are validated on vehicle. |
Investigation of Airflow Induced Whistle Noise by HVAC Control Doors Utilizing a ?쁖-Shape??Rubber Seal | Doors inside an automotive HVAC module are essential components to ensure occupant comfort by controlling the cabin temperature and directing the air flow. For temperature control, the function of a door is not only to close/block the airflow path via the door seal that presses against HVAC wall, but also control the amount of hot and cold airflow to maintain cabin temperature. To meet the stringent OEM sealing requirement while maintaining a cost-effective product, a ?쏺-Shape??soft rubber seal is commonly used. However, in certain conditions when the door is in the position other than closed which creates a small gap, this ?쏺-Shape??seal is susceptible to the generation of objectionable whistle noise for the vehicle passengers. This nuisance can easily reduce end-customer satisfaction to the overall HVAC performance. The goal of this paper is to establish (1) contributing factors, (2) correlation of the whistle noise generation to the Strouhal number, and (3) an empirical equation to predict the whistle frequency as a function of fan speed and door gap geometry. Several potential solutions are also presented. |
A Finite Element Method for Effective Reduction of Speaker-Borne Squeak and Rattle Noise in Automotive Doors | Increasing sound quality with advanced audio technology has raised the bar for perceived quality targets for minimal interior noise and maximal speaker sound quality in a passenger vehicle. Speaker-borne structural vibrations and the associated squeak and rattle have been among the most frequent concerns in the perceived audio quality degradation in a vehicle. Digital detection of squeak and rattle issues due to the speaker-borne structural vibrations during the digital vehicle development phase has been a challenge due to the physical complexity involved. Recently, an effective finite element method has been developed to address structure-borne noise [1] and has been applied for detecting the issues of squeak and rattle in passenger vehicles due to vehicle-borne vibrations at vehicle, component and subcomponent levels [2, 3, 4, 5, 6, 7, 8]. In this paper, the speaker-borne structural vibrations are simulated accurately by adapting the critical audio loads in terms of equivalent structural excitations. The squeak and rattle analysis method is extended to predict the potential squeak and rattle issues in a door system on which the speaker is mounted. Using the method, the root causes for the issues are identified and counter-measures are developed to improve the audio quality in the system effectively. Audio tests are conducted to confirm the improvement in the audio quality with the counter-measures adapted. The finite element predictions show very close correlation with the tests regarding the squeak and rattle issues with the baseline design as well as the audio quality enhancement with the counter-measure. |
Gear Lever Sound Quality Evaluation | Vehicle sound quality has become lately one of the main topics of study in the automotive industry which is associated with the quality of the product. Into the automotive development the static operational sound quality is one of the attributes that is considered. The sounds produced through the manipulation of items like the doors and interior components (windows, seats, safety belts, windshield wipers, and others) generated for safety and warning purposes are items related to the vehicle quality for customers. Those sounds based on relative level of intensity, duration, harmony and degree of contribution are elements that the customer will retain in mind, an overall quality impression. The sound produced during gear lever manipulation is important to the customer in order that the event should transmit low intensity and robust and soft impression. The purpose of this work is to evaluate this kind of event using binaural recordings inside the vehicle through subjective and objective evaluations. Psychoacoustic parameters (loudness, sharpness and roughness) and time - frequency spectrum (Wavelet transform) are proposed to correlate objective results with the subjective perception of gear lever sound quality. |
Constant Q Transform for Automotive NVH Signal Analysis | The constant Q transform consists of a geometrically spaced filter bank, which is close to the wavelet transform due to the feature of its increasing time resolution for high frequencies. On the other hand, it can be processed using the well-known FFT algorithm. In this sense, this tool is a middle term between Fourier and wavelet analyses, which can be used for stationary and non-stationary signals. Automotive NVH signals can be stationary (e.g., idle, cruise) or non-stationary, i.e., time-varying signals (e.g., door closing/opening, run-up, rundown). The objective of this work is to propose the use of the constant Q transform, developed originally for musical signal processing, for automotive NVH (run up, impact strip and door closing) time-frequency analyses. Also, similarities and differences of the proposed tool when compared with Fourier and wavelet analyses are addressed. |
The Use of a Simply Vibration Analysis Method for Optimization of Vibration Damping Material in Vehicle Panels | With the use of common office software a simplified vibration analysis method is implemented. This method makes possible a quick evaluation of the data obtained with structural dynamics testing measurements, showing the maximum values of Frequency Response Functions (FRF) and a spatial graphic representation for these maximums; with this the regions of strong vibrations are identified. The dimensions and placement of the damping material to be applied in a metallic panel is defined based in the identification of these regions of maximum vibration. Successive tests can be quickly carried out with this method, making possible to achieve the better solution for elected frequencies. The application of this methodology in the optimization of damping material placement in vehicle doors results in a considerable enhancement in closing door noise. |
Innovative Steel Solution for Doors | Reducing CO2 emissions, improving safety, reducing car weight and cutting costs are the main constraints in the design of a new door. In partnership with a design office and a Tier 1 supplier, Arcelor has designed a generic door that reduces mass by 15% without impacting costs. This design was based on a reference (D segment / one of the European ?쐀est in class??. Functional validation was achieved by comparison with this reference and industrial feasibility was validated with the help of a partner (industrial door manufacturer). A range of innovations were implemented: This presentation will describe Design principles, Functional validation Industrial feasibility. |
Cost-Effective Day & Night Marking Using Lasers | ?쏡ay & night marking??is used in automobiles, aviation, instrumentation and computer keyboards to make buttons and controls (e.g. door locks, window controls, sound system adjustments, etc.) clearly visible under ambient illumination conditions varying from bright sunlight (day) to low light (night). Although it sounds simple, manufacturing these products cost-effectively in a small-batch production environment requires the use of a sophisticated, automated, laser-based tool. |
The Effect of Seal Stiffness on Door Chucking and Squeak and Rattle Performance | Traditionally, door seals are designed to achieve good wind noise performance, water leakage and door closing effort in a vehicle design and development process. However, very little is known concerning the effect of door seal design on vehicle squeak and rattle performance. An earlier research work at Ford indicates a strong correlation between the diagonal distortions of body closure openings (in a low frequency range 0 - 50 Hz) and overall squeak and rattle performance. Another research at Ford reveals that relative accelerations between door latch and striker in a low frequency region (0 - 50 Hz) correlate well with door chucking performance. The findings of this research work enable engineers to assess squeak and rattle and door chucking performance using vehicle low frequency NVH CAE models at a very early design stage. This paper is concerned with a sensitivity study of door chucking and squeak and rattle performance with respect to door seal stiffness using two performance metrics (diagonal distortions at closure openings and relative accelerations between latch & striker) mentioned above. It is found that door chucking performance improves with the increase of seal stiffness monotonically. Whereas overall squeak and rattle performance is dictated by match boxing modes of doors and liftgate that are in turn affected by seal stiffness. No special trend is observed in terms of squeak and rattle sensitivity with respect to seal stiffness. |
Advanced Thermoplastic Composites for Automotive Semi-Structural Applications | Composite materials have found applications in the aviation industry because of an appropriate combination of properties - high stiffness, high heat performance and lower specific gravities. The Automotive industry has similar needs, and the application of composites in semi-structural application is a natural next phase. This is also necessitated because of global emphases on fuel efficiency and safety considerations in automotive applications. In this paper, thermoplastic composite material technology solutions and case studies for a number of applications, such as front-end-modules, door modules and instrument panel carriers are presented. Since processing and material modeling of composites is of critical importance in the design process, this paper also describes a new definition of isotropic properties of long glass composites, and perhaps the only way of honestly comparing such materials. This method is now accepted as an European Alliance for Thermoplastic Composite (EATC) standard. |
Application of Transient SEA for Vehicle Door Closure Sound Quality | Transient Statistical Energy Analysis (SEA) is applied as an analysis technique and compared to measured data in this study. A transient SEA model for a door closure event is developed and compared to measured data to validate this model with measured acoustic and vibration responses. The validated model is then used to predict the effect of changes to component absorption, damping, stiffness, materials, and other properties. The basic theory of transient SEA and the transient SEA model used in the study are described, the validation between analytical model and measured data is shown, and the conclusions from the analysis of design changes to the vehicle components using this model are presented. |
Cab Roof Strength Evaluation?봓uasi-Static Loading Heavy Trucks | This SAE Recommended Practice describes the test procedures for conducting quasi-static cab roof strength tests for heavy-truck applications. Its purpose is to establish recommended test procedures which will standardize the procedure for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included. |
Direction-of-Motion Stereotypes for Automotive Hand Controls | The purpose of this SAE Recommended Practice is to present design recommendations for the direction-of-motion of hand controls found in passenger vehicles, multipurpose vehicles, and trucks. These recommendations are based on recent and past human factors research and are important considerations in the design of control layouts. |
Cranes?볾ccess and Egress | This recommended practice specifies criteria for steps, stairways, ladders, walkways, platforms, handrails, handholds, guardrails and entrance openings which permit access to and from operator, inspection or maintenance platforms on mobile cranes parked in accordance with the manufacturer?셲 instruction. It also presents requirements for guards and restraints as related to moving parts. |
Ambulance Modular Body Evaluation-Quasi-Static Loading for Type I and Type III Modular Ambulance Bodies | This SAE Recommended Practice describes the test procedures for conducting quasi-static modular body strength tests for ambulance applications. Its purpose is to establish recommended test practices which standardize the procedure for Type I and Type III bodies, provide ambulance builders and end-users with testing procedures and, where appropriate, provide acceptance criteria that, to a great extent, ensures the ambulance structure meets the same performance criteria across the industry. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included. |
Automated Fastening of Aircraft Cargo Door Structures with a Standard Articulating Robot System | The demand of flexible and cost-efficient solutions for automated fastening systems inspired us to develop the robot and end-effector technology to fulfil the customer's requirement for a highly accurate, automated robot based drill and fastening system for an aerospace application. This paper describes an innovative robot cell for drilling and solid riveting installation in cargo door structures of a single aisle aircraft at EUROCOPTER in Germany. The required absolute positioning accuracy is reached by using a special compensation package for the robot that was developed by BROETJE-Automation. Our customer's application required a completely new type of end-effector; installing solid rivets and capable of operating within the inner structure of the cargo doors. This solution demonstrates how standard robots equipped with a mature compensation method by BROETJE-Automation resulted in a highly flexible and cost-efficient light weight automation response. |
Re-Design for Automotive Window Seal Considering High Speed Fluid-Structure Interaction | Automotive window seal has great influence on NVH (Noise-Vibration-Harshness) performance. The aerodynamic effect on ride comfort has attracted increasing research interest recently. A new method for quantifying and transferring aerodynamics-induced load on window seal re-design is proposed. Firstly, by SST (Shear Stress Transport) turbulence model, external turbulent flow field of full scale automotive is established by solving three-dimensional, steady and uncompressible Navier-Stokes equation. With re-exploited mapping algorithm, the aerodynamics pressure on overall auto-body is retrieved and transferred to local glass area to be external loads for seals, thus taking into account the aerodynamics effect of high speed fluid-structure interaction. This method is successfully applied on automotive front window seal design. The re-design header seal decreases the maximum displacements of leeward and windward glass with 9.3% and 34.21%, respectively. The improvement of fitting stability shows the effectiveness this seal re-design considering high-speed fluid-structure interaction. |
Mass Benchmarking Using Statistical Methods Applied to Automotive Closures | Understanding the lightweighting potential of materials is important in making strategic decisions for material selection for a new vehicle program. Frequently benchmarking is done to support these decisions by selecting a reference vehicle which is believed to be mass efficient, then using the teardown mass data to set targets for the vehicle under design. In this work, rather then considering a single benchmark vehicle or a small set of vehicles, we looked at a large sample of vehicles over a range of sizes and segments (approximately 200 vehicles). Statistical methods were used to identify mass drivers for each subsystem. Mass drivers are the attributes of the vehicle and subsystem which determine subsystem mass. Understanding mass-drivers allows comparisons across vehicle size, segments, and materials. Next, we identified those vehicles which had subsystems which were much lighter than the average after adjusting for mass drivers. This set was defined as mass-efficient designs. We then focused on the lightweighting gained by material selection for these mass-efficient designs. This paper focuses on four body closures systems: side door, hood, decklid, and hatchback door. Results include the identification of mass drivers and predictive equations for closure structure mass for both average designs and mass efficient designs; The influence of material selection on mass for both average and mass-efficient designs; and observations on the diminished mass savings achieved at the system level when there is a mass savings due to material substitution at the structure level. |
Effect of load slope time (LST) and load adaptor position (LAP) on side door strength of passenger cars: A deformation mapping matrix (DMX) approach | Side impact collisions are one of the most frequently occurring road accidents leading to occupant injury and even death. To provide better safety to occupants during such collisions, side doors and side body structures in modern passenger cars have been designed to absorb the impact energy and reduce the depth of intrusion into the passenger compartment. Side impact performance components are often evaluated by conducting a dynamic full vehicle crash test and a quasi-static side door intrusion test. The Indian regulation for side impact performance evaluation comprises of the quasi-static side door intrusion test. This paper highlights the variation in crush strength performance viz., initial crush resistance, intermediate crush resistance and peak crush resistance, due to the difference in the rate of load application as per IS12009:1995. The paper presents the deformation mapping matrix (DMX) approach to study the variation in results due to load slope time (LST) and load adaptor position (LAP). |
Simplified Side Impact Test Methodologies for Door Interior Trim Armrest in Automotive Vehicle | The complete evaluation of the side vehicle structure and occupant protection is only possible by the full-scale side impact crash test. But auto part manufactures, such as door trim makers can't conduct the test especially when the vehicle is under developing process. And important information and components for estimating crash performance is restricted. With the proposed design procedure for the door trim by a simple impact test method was demonstrated to evaluate the abdominal injury. In addition to simple test, Euro-NCAP test result that is conducted by referenced full-scale test in Korea is compared with several test results. In conclusion, this simple test method have similar trend for abdominal injury index so that it is possible to present guidelines of door armrest design to carmaker at the early stages of vehicle program development. |
Sealing and Structural Enhancement System for the Rear Cargo Ramp of a C-130 Aircraft | At flight levels above the ceiling of 10,000 feet, during the operational phase of a sensor deployment system for a C-130 aircraft, it becomes necessary to seal the cargo hold to maintain pressure for the safety and comfort of the crew and operators. In order for the sensor deployment System to have full mission support capabilities for DoD reconnaissance needs, a system must be designed where-by the cargo area may be sealed once the system has been deployed. Currently, with the sensor pod in position, the ramp can be closed to within a few inches of the locked position. The door in this position, for stability during flight, must be locked and structurally supported to maintain the aircrafts design requirements. This presents the first of a series of issues that must be examined for the success of the final design. To seal the remaining area, an expanding ?쐀ladder-seal??has been developed. This sealing device will ideally include a means of ?쐆olding??onto both the upper door and lower ramp of the aircraft simultaneously. The systems presented will create a significant advancement to the capabilities of the existing sensor deployment system for a C-130 aircraft and for the C-130 itself. This design will be completely capable of being used on any C-130 aircraft produced and will have the same universal mounting system as the current sensor deployment system. |
Electromagnetic Field Analysis for Smart Key Antenna | Currently, the drivers are able to control a door lock at a distant point from a vehicle. Recently, a door lock system has been developed to detect an owner approaching and to unlock the door when he/she touches the door handle. In this system, an antenna detects the existence of the owner with an electrical key near the vehicle. Since this detection performance of the antenna (directivity) varies in the operating area, it is essential to recognize directivity and confirm that there is unoperating area. In this report, we describe an example of predictive calculation on directivity of an antenna using the electromagnetic field analysis. |
Retention Characteristics of Production Laminated Side Windows | Field accident data have demonstrated that occupant ejection during vehicle rollover is associated with a high risk of serious and fatal injury. Although it has been demonstrated that seat belt use is highly effective in preventing occupant ejections, it has been argued that occupant containment during rollover can be accomplished with the use of laminated side glazing. This study was conducted to evaluate the retention characteristics of production laminated side windows. The current vehicle fleet was surveyed for vehicles equipped with production laminated side glass. The survey examined relevant window system parameters including glass retention system, glass configuration, and window geometry. A representative subset of five front door systems from several manufacturers was chosen for further evaluation. In addition, one legacy rear door system with laminated glass was included for comparison. Drop tests were conducted on the production component door-glass systems utilizing an 18 kg (40 lb) headform at an impact speed of 24 km/h (15 mph). None of the tested window systems retained the headform under these loading conditions. Given the results of this study, together with the NHTSA's previous measurements of occupant effective mass, it is concluded that production laminated side glass is not an effective barrier to occupant ejection during rollover. |
The Impact of the Digital Human Modeling on the Aircraft Interior Projects | The main objective of this work is to show a broad view of Digital Human Modeling software as a tool for aiding interior design projects for aircrafts. This will be achieved by showing digital manikins and their use during the development project of an aircraft interior. The time allocated to the design stage could be shortened and the costs concerning mock-up fabrication and certification were lowered because of this program's application during the entire process. The influence can be noted because of the ease to study monuments on high-density configurations, usability and accessibility of the door handles and on-board attendant visibility, etc. This paper is merely conceptual and do not involve existing aircrafts data or in development. |
System Level Noise Source Identification and Diagnostics on a Vehicle Door Module | Noise problems are often system issues rather than component issues. Component manufacturers have been putting continued efforts into constantly improving the quality of their products. There are numerous tests and standards to assess the vibro-acoustic performance of individual components. But once all components are put together, the system response might be entirely different from those of individual components. Typical system level testing has primarily been used to identify bad assembled products from good ones. These tests are usually done as part of a quality control process and slow down production. Such tests usually provide little information about the root causes of noise and vibration problems and no insight into improving engineering designs for noise abatement. This paper presents a new way of conducting system level noise diagnoses by using the Helmholtz Equation Least Squares (HELS) based Nearfield Acoustical Holography (NAH) technology [1]. This approach allows for reconstruction of all acoustic quantities, including the acoustic pressure, particle velocity, and acoustic intensity, and creating 3D acoustic images produced by an arbitrary source based on the acoustic pressures measured on a hologram surface at very close range to the source. It enables one to establish a direct correlation between sound and vibration. The current study involves a noise diagnostic test on a vehicle door assembly to understand system level interaction of the motor and the door module to compliment continued efforts to refine the motor to manufacture quieter assemblies. To identify noise sources, a conformal microphone array, covering the entire door surface was used to measure the acoustic pressures. This data was used to reconstruct the acoustic pressure, normal velocity, and acoustic intensity on the door module surface. In particular, the acoustic intensity and normal surface velocity were analyzed to identify the noise sources and understand the noise generation mechanisms. |
Implementation of a correlation technique for fuel tank sled crash test | The fuel tanks produced in sheet metal forming needs to attend safety requirements regarding the vehicle collision. One of the validation tests is the sled crash test. This test is based on the impact of a sled with a certain profile and energy (defined by rules) against a fuel tank. During the crash are evaluated: deformation, internal pressure, cracks, leaks and the energy absorbed. To avoid trial-and-error methods in the product development stage, the use of numerical simulation has increased in the past years and made the validation process faster and cheaper. One difficulty of this procedure for validation of numerical results is the correlation between the level and the deformation mode of the tank, once the internal pressure and the energy can be measured by special sensors. The main objective of this work was to propose a methodology to correlate the deformed geometry of the fuel tank, using a 3D scanner, with the numerical simulation results. The software used to simulate the crash was Radioss, which has a suitable formulation for events involving large non-linearity. The results are promising and the methodology implemented can be used for other products that involves crash test in the validation, such as bumpers and doors. |
Development and Application of an Enhanced SID-IIs Dummy for Analyzing Side Impact Kinematics | Due to the relative high speed and short distance between the door and occupant, side impact presents a challenging task when analyzing the input force from the door to the occupant. The new FMVSS214 Final Rule in 2007 and the new NCAP in 2008 mandated the use of a SID-IIs in the oblique pole impact test and in the rear seat during an MDB side impact test. Therefore, a high-precision measurement and calculation of the three-dimensional dummy kinematics, as well as the interaction of force inside the dummy (internal force) and force exerted from outside the dummy (external force) will help provide efficient evaluation of design requirements for the door trim and supplemental restraint systems that meet legally mandated requirements. This paper demonstrates that the SID-IIs three-dimensional kinematics and external forces can be calculated with a high degree of precision through the addition of angular rate sensors and force transducers, and describes the application of the technique to vehicle development. |
Design of Dual Sliding Door Mechanism for a Small Sized Car | Swing-out doors can easily cause damage to adjacent parked vehicles in tight parking spaces. Also, they are not traffic-friendly when the vehicles are parallel parked on busy road sides. This paper makes an attempt to come up with an innovative to design and develop a mechanism for dual sliding doors for a small sized car. The doors are supported only on two points of contact as compared to the usual sliding minivan doors which have three contact supports for sliding. These two points are called the ?쏹pper control link and Lower support arm?? To open the door, first the door, has to push out by 90 degrees and then it has to slide in the fore-aft direction to open or close. For the doors, a track was placed just below the window at the beltline location and a triangular sub-roller assembly was designed for sliding motion. A rail was placed on the rocker panel of the space frame which has three rollers assembled in such a way that they would compensate for the weight of the door and rigidly secure the door during sliding. This paper explains the mechanism in detail and also discusses safety issues linked to selection of engineering materials for the doors. |
Load Path Considerations for Side Crash Compatibility | Heavier, larger pickups and SUVs are bound to encounter lighter, smaller passenger vehicles in many future accidents. As the fleet has evolved to include more and more SUVs, their frontal structures are often indistinguishable from pickup fronts. Improvements in geometric compatibility features are crucial to further injury prevention progress in side impact. In corner crashes where modern bullet passenger car (PC) bumpers make appropriate geometrical overlap with target PC rocker panels, concentrated loads sometimes disrupt foam and plastic bumper corners, creating aggressive edges. In situations where sliding occurs along the structural interface, these sharp edges may slice through doors, panels and pillars. End treatments for such bumper beams should be designed to reduce this aggressive potential. The experimental comparison presented here demonstrates that load path compatibility can provide a means by which severe door intrusion due to oblique corner impacts may be reduced without severe weight penalties to the vehicles involved. |
A Dynamic Sled-to-Sled Test Methodology for Simulating Dummy Responses in Side Impact | This paper describes the development of a sled-to-sled test methodology to simulate the occupant responses in different side impact cart test modes. For evaluation of various inflatable restraints (Thorax SAB, Head-Thorax Combo SAB, Pelvis-Thorax Combo SAB), the simulation of ?쁤ap closure??between dummy and door is desirable to achieve satisfactory SAB performance, besides obtaining good correlation of occupant responses between full-vehicle tests and sled tests. This methodology uses a combination of three sleds - Bullet, Door, and Seat sleds to simulate the entire door velocity profile in two phases - Phase I: Gap Closure till Door-Dummy contact occurs, Phase II: Door-to-Dummy contact till separation. The initial pre-crash distance between dummy-to-door trim is achieved by positioning the Door sled relative to the Seat sled (with dummy). The Bullet sled strikes the stationary Door sled with a pre-determined initial velocity, which accelerates the Door sled to a peak velocity within a predetermined time from contact (also dummy-to-door contact velocity) to simulate Phase-I of the door velocity profile. The Door sled then strikes the stationary Seat sled with Dummy. After door-to-dummy contact, the Bullet and Door sleds are decelerated by a VIA decelerator to simulate the Phase-II of the Door velocity profile. |
Hybrid Design for Automotive Body Panels | The increasing trend for electric mobility adoption brings new challenges to the automotive industry, requiring a new approach to the manufacture processes, materials adopted and adaptation the market needs. The conventional technologies used to manufacture automotive parts imply significant overhead costs (tooling, assembly, etc.) which can only be justified by large series. The need of light and cost effective materials was the driving force of this study, acknowledging that the growth of the electric vehicles market will be driven by price. The study aims to deliver a hybrid design material solution that would offer quality and security to the vehicle, affordable to everyone, developing engineered solutions in terms of design and production process. To the study were considered exterior body panels that are conventionally manufactured by sheet metal stamping or conventional thermoplastic injection, both having associated high investment costs related with tooling. To follow up this case study was defined as constrains that small series should be considered and weight reduction has to be achieved. The adoption of engineered materials leading to hybrid body panel's configuration was studied with increased resistance and reduced weight, using processes with low cost assembly operations and low tooling investment for a start. Structural reinforcement inserts were used on the test case to provide the desired results on the final component behavior. The approach taken, considered different materials and methodologies focusing on the use of DCPD RIM components having as baseline the materials used nowadays in the automotive industry for the same type of exterior body panels. For deeper understanding on exterior panels' state of art, an analysis through several vehicle doors was made, analyzing the materials used and their combination. As a result, different combinations of materials were considered as adequate for weight reduction and for production on small production series. Virtual simulation of two exterior body panels' solutions was done demonstrating the potential of DCPD as a hybrid solution to deliver structural consistence in conjunction with weigh reduction at a reduced cost. |
Automation for Unprecedented Production Rates | Unprecedented rates in Boeing 737 aircraft production have driven a need for an increase in capacity in fuselage manufacturing and assembly. This paper will discuss the requirements by Spirit AeroSystems to add capacity, and the new and upgraded machinery provided by Broetje Automation in response to these requirements. Production areas found to require additional capacity included galley and entry door skin fastening, as well as frame fastening in upper and lower lobes. Three new Mobile Panel Assembly Cell (MPAC) machines were installed in rapid succession for efficient and flexible production of door panels. For frame fastening of upper and lower lobes, three existing machines were taken out of production one at a time for a comprehensive upgrade resulting in process speed increases of more than 40%. |
Oil Filter Clogging Rule - Correlation between Mileage and Lab Test Clogging | Oil Filter change interval is widely defined as a mileage, expressed in Kilometres/Miles of the Vehicle driven. On the other hand, for convenience, repeatability and differentiation reasons, the Filter life time is evaluated in the laboratory test bench according to standard test methods. The Life Time is expressed in grams of calibrated dust injected into the filter inlet so as to clog it. The most commonly used test standard is ISO 4548-12 [7]. So far, there is no widely known and recognized relation between the service time in kilometres and the dust holding capacity according to ISO standard. The purpose of the following study was to establish a relationship between ISO standard dust capacity and the ability of the filter to successfully achieve the service interval in 90% of cases. A large number of used filters were collected and analysed in order to conduct a statistical analysis. Impacts of fuel type, engine displacement and road conditions were identified. At the end a clogging rule was established. The paper concludes that for some filter applications, it is possible to reduce the required ISO dust capacity which opens the door to filter size reduction or enhanced engine protection through higher filtration efficiency. |
Development and Validation of Numerical Model for Standardized Oberst Beam Test (ASTM E 756-98) | Currently, the simulation models in acoustics and vibrations are built considering only the main structures of the vehicle, as its basic structure (Body-in-white, BIW), doors, dashboard, and so on. To take into account the contribution of components with less influence (such as carpets, seats, sound insulation, and so on) in the behavior of the overall response of the model, the average characteristics of these materials are inserted evenly distributed in these models. However, to obtain models with better correlation levels is necessary to consider local characteristics of the application of these components. In this work was developed and numerically validated, the model that describes the standardized test of ?쏰berst Beam??(ASTM E 756-98) to obtain the damping of the blankets used for damping of the panel vibration. With these characteristics, in future work, is expected to be possible, also with a good correlation, consider the effect of these materials on whole vehicle. |
Numerical Simulation of the Vibro-Acoustic Behavior of a Vehicle under Operating Conditions | Currently the numerical simulations of the vibro-acoustic behavior of vehicles are built considering only major structures, such as its basic structure (body in white), doors, dashboard etc. To take into account the contribution of other components (such as trims, seats, sound insulation etc.) to the overall response of the model, the average characteristics of these materials are inserted globally in this model. However, for more correlated models is necessary to consider local characteristics of these components. This work presents the numerical procedure for simulating the effect of the structural damping of viscoelastic coatings and the acoustic absorption of the trims such that its effects can be considered in the model of the full vehicle. The operating forces applied to the model were estimated from the laboratory and road tests using the SPC/TPA technique. Furthermore, the model enables the subjective evaluation of the noise from the auralization/synthesis based on numerical frequency response functions and road test data. |
A Study on New Approach of Optimization for the Automotive Plastic Interior Parts | Carmakers have tried to lower the vehicle weight for raising fuel efficiency. This trend involves a trade-off with the vehicle stiffness. In automobile interior parts, the thickness has needed to be decreased for the weight reduction but this makes the stiffness worse. A new approach for improving the stiffness due to the weight reduction is required and various optimization methods at early development stage have been introduced currently. However, it is difficult to apply optimization for the interior parts since many interior parts' structures generally depend on the design. But as studying the structure in detail, we discovered some factors that affect the performance without depending on design. The door trim is selected for optimization item because it has many characteristics of automobile interior parts. In our case study, the factors that improve the performance of door trim without changing design are considered as fastener position and flange rib layout. The optimization process for door trim was established. Size optimization is used for Fastener position and Topology optimization is used for Flange rib layout. As a result, the 1st mode frequency is improved by about 5% and thermal displacement is reduced by about 25% in comparison with the initial model. |
DPIV Measurements of the HVAC Aerodynamics Inside a Passenger Car | DPIV (Digital Particle Image Velocimetry) measurements of the HVAC (Heat, Ventilation and Air Conditioning) system aerodynamics inside the compartment of a passenger car will be presented. The measurements were carried out in a commercial version of a car. No modifications were made to the car other than substituting the doors on the passenger side for transparent acrylic sheets. In DPIV the flow is seeded with particles with size in the order of microns and the flow is illuminated by a planar pulsed laser sheet. The particles scatter the light and one or more high speed cameras, synchronized with the laser pulses, record images of the illuminated particles. Image processing of the obtained images allows the calculation of the velocity flow field. The seeding for these experiments was produced using a custom made Laskin nozzle atomizer and olive oil. Flow velocities were measured in several vertical longitudinal and transverse planes, as well as in horizontal planes, covering very large areas inside the cabin of the car with high spatial resolution. Results showing the mean and the standard deviation of the velocity flow fields inside the cabin will be presented. The work reveals how DPIV can be used in the design and validation process of HVAC systems, in order to study the instantaneous flow fields and the main structures inside the cabin for each HVAC configuration desired. |
Research on Torsional Characteristic of Separate Frame Construction for a Light Off-Road Vehicle | A key problem of designing a light off-road vehicle with separate frame construction is to improve its torsional characteristic, which has a significant influence on the performance of the vehicle. Inevitably, a certain distortion of the body would be produced by the vibration and impact passing from the road. In present research, an analysis model of light off-road vehicle is established based on the theories and methods of finite element (FEM). The static stiffness of the body is simulated and the deformation of openings on the body, mainly the windows and the doors of the vehicle is studied. On the working conditions of torsion and braking combination, torsion and cornering combination, diagonal dangling, ultimate torsion of unilateral wheels and diagonal wheels, the static strength of separate frame construction is studied as well. The stress concentration regions are obtained according to the results of simulation. Theoretically, this paper studied the torsional characteristic of separate frame construction in terms of static stiffness and static strength and the most vulnerable regions are figured out, which offers an important support for the optimization of vehicle structure. |
Aeroacoustic Noise Generated by Air Flowing through a Slit in an HVAC System | Air flowing through a narrow slit sometimes generates noise. This phenomenon has been identified in some parts of automobile HVAC systems. The noise annoys drivers and passengers and causes deterioration in the automobile?셲 quality. Simply sealing the gap is a way to avoid such flow noise. In an HVAC system, however, the doors that control the air flow are openable, and the door slits, which are difficult to eliminate, emanate the noise in transient conditions. The noise is well known, but the mechanism of noise generation has not been well studied to date. Computational fluid dynamics (CFD) has been a useful tool for air flow studies, but commercial CFD programs usually use a turbulence model such as Reynolds-averaged Navier-Stokes (RANS); in addition, the flow behavior result depends on the model selected in the calculation. In this study, direct numerical simulation (DNS) of the compressible subsonic flow without a turbulence model is adopted to investigate the flow through a narrow slit and its associated noise generation mechanism. The numerical results show the relationship between the noise and the unsteady vortices created through the slit. This study also explains the process of slit noise creation by comparing the force caused by vortices from the wall to the air and the noise. |
Experimental Investigation on Mechanical Properties and Vibration Damping Frequency Factor of Kenaf Fiber Reinforced Epoxy Composite | Kenaf Fiber regarded as industrial crop for different applications. It is one of the most important plants cultivated for natural fibers globally. Natural fibers such as kenaf fibers are getting attention of researchers and industries to utilize it in different composites due to its biodegradable nature. In this present investigation mechanical properties, vibration damping frequency factor and thermogravimetric analysis of kenaf fiber reinforced epoxy composite (KFREC) have been evaluated and reported. The tests were conducted with different weight categories of kenaf fiber such as 20%, 25%, 30% and 35%. The effects of fiber content on tensile, flexural, impact strengths, hardness and thermal decomposition properties of the composite were determined. The failure mechanism and damage features of the KFREC were categorized using Scanning Electron Microscope (SEM). The results indicate that the increase in the fiber content decreases the damping vibration factor (瓘) correspondingly. The lowest value of the damping vibration factor was recorded as 0.033 for 35% weight content of Kenaf fiber in the composite. The maximum value of hardness, tensile, flexural, and impact strengths were noted as 447 BHN, 45.62 MPa, 124 kN and 13.2 J respectively and the effective thermal decomposition range was 378.64 - 442.18 째C for 35% of kenaf weight content KFREC. From the results it is identified that the kenaf fiber at 35% weight content reinforced with epoxy resin will be suitable for structural application in automobiles such as bumper beams, door panels and front modules. In addition to that the light weight nature of the kenaf fiber will help in achieving fuel economy in automobiles. |
Crash-induced Loads in Liftgate Latching Systems | Automotive liftgate latches have been subject to regulation for minimum strength and inertial resistance requirements since the late 1990?셲 in the US and globally since the early 2000?셲, possibly due to liftgate ejections stemming from the first generation Chrysler minivans which employed latches that were not originally designed with this hazard in mind. Side door latches have been regulated since the 1960?셲, and the regulation of liftgate, or back door latches, have been based largely on side door requirements, with the exception of the orthogonal test requirement that is liftgate specific. Based on benchmarking tests of liftgate latches, most global OEM?셲 design their latches to exceed the minimum regulatory requirements. Presumably, this is based on the need to keep doors closed during crashes and specifically to do so when subjected to industry standard tests. The focus of this paper is to understand the specific loads seen by center-mounted liftgate latches when exposed to various industry standard tests, as well as some foreseeable crash conditions currently not addressed by the standard tests. This paper explores the use of CAE analysis to understand the specific structural and inertial loads liftgate latches are exposed to in various rear and side crash tests, in order to better understand the design requirements for liftgate latches to ensure passenger compartment integrity and minimize the risk of occupant ejection through the liftgate closure. Various standard crash tests, vehicle body types and cargo load cases are explored as well. A methodology is presented which shows how the various load cases can be obtained and used for development of new liftgate latches. This paper does not deal with roll over load cases, which is a subject of ongoing research and will be presented in a subsequent paper. |
The Effects of Internal Friction on Automotive Latch and Release System Behavior | Physical tests and analysis of a typical automobile latch and outside handle release mechanism are performed to determine the effects of friction on the systems dynamic response. An automobile side door outside handle, outside handle rod linkage, and latch are mounted to a rigid fixture that is constrained by bearings to a ?쐂rop tower.??The fixture is released from controlled heights onto a compliant impact surface resulting in a constant duration acceleration transient of varying amplitude. An instrumented door latch striker is designed into the fixture to engage the latch. The pre-drop interface load between the latch and striker is adjusted allowing its effect on the dynamic behavior to be characterized. The latch position and the interface load between the latch and striker are monitored throughout the test. The results of the test show that friction forces internal to the latch significantly affect the quasistatic and dynamic behavior of the latching system. |
Understanding the Stick Slip Behavior of Plastics and Target Setting: An OEM Perspective | Automotive OEMs are aggressively using different materials for interiors due to value proposition and variety of options available for customers in market. Excessive usage of different grade plastics with zero gap philosophy can cause stick slip effect leading to squeak noise. Even though systems and subsystems are designed using best practices of structural design and manufacturing tolerances, extreme environmental conditions can induce contacts leading to squeak noise. Appropriate selection of interface material pairs can minimize the possibilities of squeak conditions. Stick-slip behavior of different plastics is discussed in the present study, along with critical parameters during material compatibility testing in a tribological test stand. Friction coefficient of different material pairs for a defined normal load and sliding velocity are analyzed for patterns to recognize squeaks versus time. An OEM perspective is presented with focus on material selection using objective metrics like coefficient of friction and set targets for raw material suppliers regarding compatible materials. In the next step, an algorithm based on machine learning approach has been developed for estimating stick-slip performance. |
Dust-Sized Sensors Could Create ?쏣lectroceuticals??"University of California | Berkeley engineers have built the first dust-sized |
Robotic Modules Modify Their Environment for Specific Tasks | Given the exact parameters of the task at hand, a robot can assemble a car door or pack a box faster and more efficiently than a human, but such purpose-built machines are not suited for much else. With that in mind, the history of robotics research is marked by devising ways of giving machines more and more autonomy. To achieve that end, robots must be able to sense features of never-before-seen environments and know how to interact with them. |
Horsepower, kilowatts compete at 2019 GENEVA MOTOR SHOW | Is Europe getting serious about electric vehicles? Look no further than the EV-intensive 2019 Geneva motor show. There still was plenty of old-school horsepower making news at this year's Geneva motor show in early March, but there was no question it's fast becoming a kilowatt kinda world. The number of electric and electrified vehicles-concept and production-ready-on display made it abundantly clear that at least in Europe, electrification's ?쐇f??definitely is no longer a question. And the ?쐗hen??appears to be pretty darn soon. Although there were legitimate newsmaking vehicle introductions all over the Geneva show, the poster child for Europe's intensifying enthusiasm for electrification had to be Honda's E Prootype (see page 10), a near-production version of the universally praised Urban EV Concept shown at Frankfurt in 2017. The Urban EV's funky front bench seat is replaced by a familiar seating setup and the twin suicide doors also have morphed into four conventionally-hinged doors, but the e Prototype remains alluringly proportioned for the European market. And its rear-drive layout indicates Honda may not intend the production version to be a dull urban-transport pod. |
Aircraft Landing Noise Reduction Liners | NASA Langley Research Center has developed two new implementations of acoustic liners for aircraft noise reduction whereby curved channels within tight spaces can be outfitted to provide noise reduction. The two implementations are flap side edge liners and landing gear door liners for airframe noise reduction. In these applications, the acoustic liner is designed primarily to reduce aircraft noise that occurs during landing, which will help aircraft comply with increasingly stringent airport noise restrictions. |
Door Latch Vulnerability to Rollover Induced Loads | Light truck and SUV rollovers often involve ground contacts at the roof rails or door sills that can induce significant vertical shear loads at the latch/striker interface. These vertical loads are not evaluated in Federal Motor Vehicle Safety Standard testing yet they are known to cause latch failures. Such failures expose both belted and unrestrained occupants to increased injury risk. An example of two such failures can be found in open literature in a single van rollover test. A simple vertical load test for latches is described by the authors and evaluated for discrimination, suitability and repeatability. This test was applied to an array of current and past generation latches found on many popular SUVs and light trucks. A large range of failure loads was encountered. A review of the structural features of the superior performing test samples suggests simple modifications that could dramatically improve performance of the remaining latches. Improved performance in this vertical load test could be expected to translate to fewer unwanted door openings and ejections in field accidents. |
Invisible Advanced Passenger-Side Airbag Door Design for Optimal Deployment and Head Impact Performance | Hard panel types of invisible passenger-side airbag (IPAB) door system must be designed with a weakened area such that the airbag will deploy through the Instrument Panel (IP) in the intended manner, with no flying debris at any required operating temperature. At the same time, there must be no cracking or sharp edges in the head impact test (ECE 21.01). If the advanced-airbag with the big difference between high and low deployment pressure ranges are applied to hard panel types of IPAB door system, it becomes more difficult to optimize the tearseam strength for satisfying deployment and head impact performance simultaneously. We introduced the ?쁎perating Window??idea from quality engineering to design the hard panel types of IPAB door applied to the advanced-airbag for optimal deployment and head impact performance. To accurately predict impact performance, it is important to characterize the strain rate. |
Grade and Gage Sensitivities to Oil-Canning Loads of a Door Assembly Considering Forming Effects | A finite element methodology, based on implicit numerical integration procedure, for simulating oil-canning tests on Door assemblies is presented. The method takes into account nonlinearities due to geometry, material and contact between parts during deformation. The simulation results are compared with experimental observations. Excellent correlation between experimental observations and analytical predictions are obtained in these tests. Armed with the confidence in the methodology, simulations on a door assembly are conducted to study the gage and grade sensitivities of the outer panel. The sensitivity studies are conducted on three different grades of steel for the outer panel. Further studies are conducted to understand the effects of manufacturing (forming operation) on the oil canning behavior of door assembly. Results demonstrate the utility of the method in material selection during pre-program design of automotive structures. |
Optimization of the Side Swing Door Closing Effort | In the automotive industry, a lot of attention has been paid to the effort required for opening/closing the doors, and for a good reason. The door closing and opening effort creates an impression in the customer's mind about the engineering and quality of the vehicle even before he or she steps into it. Although this is such an important issue, the precise quantification of what constitutes a good performance target for the door opening/closing effort, has remained somewhat elusive. Thumb rules and best practices abound in the automotive industry. Some of the rules and best practices have focused on setting certain targets for the energy required to shut the door from a small open position (around 10-15 degrees). This target can be misleading. The purpose of this paper is to present an ADAMS짰 simulation model that includes all the different components of the door design. The complete opening/closing motion is a result of the interaction of the different components of the door closing system, such as the latch, weather seal, energy loss due to air-binding effect, the inclination of the hinge axes, check-link etc. The analysis simulates the entire opening/closing motion and the energy/force required during this motion. Analyzing the details of the door opening/closing motion of different vehicles, and associating this information to the customer dissatisfaction figures from sources like JD Power quality survey, enables us to more precisely quantify the target performance that will result in greater customer satisfaction. |
Developments in Thermoplastic Door Modules | The use of door modules as a pre -assembled functional unit inside a car door is discussed. This includes reasons why a door module should be used and why a long glass fiber reinforced polypropylene (PP) product is a good material of choice. As an example the development of the door modules for the new Ford Fiesta is given, including the mechanical and production design of the StaMax짰 P long glass PP carrier. * Special attention is paid to the excellent dimensional reproducibility of this material which is critical for door module designs in which the carrier also manages the wet and dry separation (e.g. ?쐓ealed??designs). Further integration potential for future door modules is also highlighted. |
A Design Study to Determine the Impact of Various Parameters on Door Acoustics | Once the design of a door sheetmetal and accessories is confirmed, the acoustics of the door system depends on the sound package assembly. This essentially consists of a watershield which acts as a barrier and a porous material which acts as an absorber. The acoustical performance of the watershield and the reverberant sound build-up in the door cavity control the performance. This paper discusses the findings of a design study that was developed based on design of experiments (DOE) concepts to determine which parameters of the door sound package assembly are important to the door acoustics. The study was based on conducting a minimum number of tests on a five factor - two level design that covered over 16 different design configurations. In addition, other measurements were made that aided in developing a SEA model which is also compared with the findings of the results of the design study. |
A Comprehensive Study of Door Slam | As part of an ongoing technical collaboration between Ford and Rouge Steel Company, a comprehensive study of door slam event was undertaken. The experimental phase of the project involved measurements of accelerations at eight locations on the outer panel and strains on six locations of the inner panel. Although slam tests were conducted with window up and window down, results of only one test is presented in this paper. The CAE phase of the project involved the development of suitable ?쐌ath??model of the door assembly and analysis methodology to capture the dynamics of the event. The predictability of the CAE method is examined through detailed comparison of accelerations and strains. While excellent agreement between CAE and test results of accelerations on the outer panel is obtained, the analysis predicts higher strains on the inner panel than the test. In addition, the tendency of outer panel to elastically buckle is examined. The implications of the buckling of the outer panel are discussed. The effects of thickness distribution and plastic strains introduced on the inner and outer panels due to forming are studied. The results show that the strains on the inner panel can be significantly influenced when forming effects are accounted for. The effect of forming on the accelerations of the outer panel can be less intuitive. This is possibly due to the buckling of the outer panel during the slam event. |
New Methods of Side Impact Simulation for Better Waveform Reproduction and Door Interaction | As a result of the severity of occupant injuries during a side impact collision, there has been an escalating demand for accurate component level side impact simulation. Three major components for accurate simulation are accurate door velocity, door to seat relative velocity, and door deformation. This paper shows data demonstrating accurate door velocity reproduction, presents test methods to passively and actively control relative seat to door velocity in a non destructive manner, and presents test methods to simulate real time door deformation in a destructive manner. All side impact waveforms include a negative acceleration, high positive accelerations, high jerk, and high frequency content that add to the complexity of this simulation. The simulated door velocity is produced by means of a MTS deceleration brake that only applies a braking force during the deceleration portion of the waveform to maximize acceleration capacity. The proposed methodologies introduce a controlled damper technology (patent pending) to actively control the transmitted forces between independent components during the simulation. |
Analysis of the Influence of the Seal Structure on Door Closing Force for SANTANA | In order to evaluate the influence of the seal structure on door closing force, nonlinear finite element method is introduced to analyze compression deformation of a door seal for SANTANA (name of the car made by Shanghai Volkswagen Co. Ltd) in this paper. The computed results show that the compression loads of the door seal are larger than the standard value of Shanghai Volkswagen Co. Ltd and the seal structure needs to be optimized. The computed results are proved by experiment. |
Vehicle Door Latch Safety Measures Based on System Dynamics | The governments of many countries have established regulations that address the issue of vehicle door safety during crash events. Depending on the regulation or specification, analytical tools may be acceptable for verifying the crashworthiness of a latching system. In those instances where actual test crashes are required for verification, analytical methods can still be used to help predict the outcome of a crash test. Two relevant analytical approaches for multibody dynamics computation are discussed in the paper. One is related to monitoring the effects of constant 30G inertia loading in all directions (spherical analysis) and another addresses inertia pulse loading of specified G levels in certain directions. In some crash situations, the latch system compliance with the regulations may be insufficient to prevent door release. To secure the door in the latched position additional safety devices can be deployed in various locations of the door latch system. One group of such devices relies on using inertia catch levers triggered by specific acceleration of vehicle door. The development and tuning of the inertia catch devices is done by analytical means followed by latch system validation during crash tests. |
Door Overbend - Design Synthesis & Analysis | This paper describes the analytical methodology for calculating the overbend needed in the door design to counteract the non-linear seal forces acting on the door header. Overbend in the door design will allow the Original Equipment Manufacturer to achieve competitive above belt flushness and gap dimensional targets at static equilibrium of the door header and weatherstrip. This method combines two analytical models of the weatherstrip and the Door-In-White (DIW) to forecast the design overbend necessary to achieve good fit and finish. These models are: 1) Seal compression-load deflection (CLD) models for each angle of attack of the weatherstrip to the door 2) A nonlinear Finite Element Analysis (FEA) model of the trimmed DIW. Bringing these two elements together to model the static equilibrium deflection, this is developed, into overbend requirements. The design synthesis process to meet the overbend design criteria is demonstrated. This method improves product quality and reduces door fit warranty by producing a product design that comprehends the inherent deflection of seal loads on the door structure. |
A Discussion on Interior Compartment Doors and Latches | Interior compartment doors are required by Federal Motor Vehicle Safety Standard (FMVSS) 201, to stay closed during physical head impact testing, and when subjected to specific inertia loads. This paper defines interior compartment doors, and shows examples of several different latches designed to keep these doors closed. It also explores the details of the requirements that interior compartment doors and their latches must meet, including differing requirements from automobile manufacturers. It then shows the conventional static method a supplier uses to analyze a latch and door system. And, since static calculations can't always capture the complexities of a dynamic event, this paper also presents a case study of one particular latch and door system showing a way to simulate the forces experienced by a latch. The dynamic simulation is done using Finite Element Analysis and instrumentation of actual hardware in physical tests. |
Simulation Methods for Door Module Design | With the automotive industry moving towards higher durability targets, reduced product development cycle time, and lower design costs, the need for simulation has never been higher. This paper explains the use of simulation techniques in the design and development of door module. A step-by-step approach to simulate a door slam event is proposed. Fatigue life estimation using simulation results is also discussed. Finally, simulation benefits are illustrated with a simulation-test case study completed at ArvinMeritor that resulted in a fatigue life improvement of more than 50%. The scope of this paper is limited to simulation methods for door slam. Test methods to collect data for door slam simulation are not discussed. |
An Experimental Investigation About Cable Efficiencies in Current Automotive Door Systems | Based on experimental and analytical research, a design tool was developed to estimate engineering parameters for side door latch inside release cables, given a pre-determined operating range. This design tool accurately estimates the cable efficiency for a set of parameters, thus significantly reducing the design time for latch and cable related engineering issues. Through testing and data analysis, the study determined the relationship between performance factors such as cable efficiency and effort losses, and design factors such as cable type, routing and loading conditions. Experimental data was used to generate curve fit equations that predict the cable efficiency for side a door latch system level development. |
Environmentally Friendly Door Sash Tape | Coating black paint on the door sash of automobiles has been a separate process from the body coating. Recently, moany automotive manufacturers are switching this secondary coating process to adhesive tape technology for various advantages. These advantages include reduction of VOC (volatile organic carbon), rationalization of assembly process, cost reduction and so on. Since this application is considered a variation of exterior decal film, most of the commercially available products are currently based on PVC (Polyvinyl chloride) film. (See Photo 1.) The automotive industry has increasingly been sensitive to the use of PVC due to its potential environmental problems. One of the problems is that the product cannot be incinerated when disposed of since it generates hydrogen chloride gas, dioxin and other toxic chlorinated organic matters. Also, reportedly its plasticizer may act as an endocrine disruptor (also known as ?쁝n environmental hormone?? when dissolved in water. Nitto Denko has developed an environmentally friendly polyolefin door sash tape as an alternative to the PVC tape. By optimizing polymer chemistry and film composition, the new polyolefin door sash tape exhibits high dimension stability in physical properties for a wide range of temperatures. Also, proprietary surface conditioning of this film ensures resistance to long-term outdoor exposure. An acceleration test has proved that the product retains 93% of glossiness compared to that of initial, with colorimetric change (delta E*ab) of only +0.12, for six and half years equivalent of solar ray radiation. Also, we did not detect toxic gases when we performed incineration tests. Only water vapor, carbon mono-oxide and carbon dioxide were detected in the given detection limit. This test has clearly demonstrated that the product causes significantly lower environmental damage than that of PVC. |
3D Audio Reproduction via Headrest Equipped with Loudspeakers?봊nvestigations on Acoustical Design Criteria | This paper focuses on the analysis and evaluation of acoustical design criteria to produce a plausible 3D sound field solely via headrest with integrated loudspeakers at the driver/passenger seats in the car cabin. Existing audio systems in cars utilize several distributed loudspeakers to support passengers with sound. Such configurations suffer from individual 3D audio information at each position. Therefore, we present a convincing minimal setup focusing sound solely at the passenger?셲 ears. The design itself plays a critical role for the optimal reproduction and control of a sound field for a specific 3D audio application. Moreover, the design facilitates the 3D audio reproduction of common channel-based, scene-based, and object-based audio formats. In addition, 3D audio reproduction enables to represent warnings regarding monitoring of the vehicle status (e.g.: seat belts, direction indicator, open doors, luggage compartment) in spatial accordance. Furthermore, individual sound zones enable superior in-car communication between seats regardless of the current driving situation. An often overlooked topic is the acoustical privacy of in-car systems towards the exterior especially during telephony which is also tackled by the presented design as a by-product. We present how the structural shape, the assembly and alignment of the loudspeakers affects the frequency response, the effective sound pressure levels at the passenger?셲 ears, the inter-aural crosstalk, and the crosstalk to other seats. We further show that person affects the sound field by movements and therefore can change the overall performance. Finally, we present our approach for 3D audio reproduction for the car cabin schematically. |
CAE Support to Vehicle Audio Installation Issues | Audio CAE is an emerging area of interest for vehicle OEMs. Questions regarding early stages of the vehicle design, like choosing the possible positions for speakers, deciding the installation details that can influence the visual design, and integration of the low frequency speakers with the body & closures structure, are of interest. Therefore, at VCC, the development of the CAE methodology for audio applications has been undertaken. The key to all CAE applications is the loudspeaker model made available in the vibro-acoustic software used within the company. Such a model has been developed, implemented and verified in different frequency ranges and different applications. The applications can be divided into the low frequency ones (concerning the installation of woofers and subwoofers), and the middle/high frequency ones (concerning the installation of midrange and tweeter speakers). In the case of the woofer, it is the interaction with the body vibration that is of interest. Hence, the loudspeaker has to be used in a full vibro-acoustic Trimmed Body model. For the higher frequencies (midrange & tweeter) the body can be treated as locally reacting, if not rigid. The examples of the verification of the speaker model versus test data for a woofer mounted in a car door will be shown, together with applications to woofer installation issues. Regarding high frequencies, examples will be shown of the comparison of different grille variants and the evaluation of the position of the speaker on the sound quality at the listeners??positions. Future developments will be discussed. |
Asian Consumers Challenging the NVH Performance of European Cars - Implications on the Product Development in the 2020ies | Sales of SUV and luxury cars on the largest market of the world - China - are growing at a high rate. The highways in large cities like Beijing or Shanghai are increasingly populated with cars from all over the world like Japan, USA, Europe and Korea and even some refined domestic brands. More than 10 million rich people can afford those cars and are skilled drivers. This huge group of potential consumers is targeted by luxury brand OEMs and by startup companies. It has been understood that these people have a high expectation of comfort. The twistbeam rear axle was replaced by multilink, double clutch transmissions were improved by comfort-mode drive programs, interior trims raised to Western standard performance levels, tyres specially developed for comfort in China, localized insulation materials and packages engineered to a one vehicle class higher level. The European avant-garde is capable of such high levels of complete vehicle NVH performance, whereas premium brands often compromise NVH with respect to high vehicle dynamics performance and passive safety requirements. Furthermore, the preference of Chinese consumers by long vehicles as a symbol of status and flaunting their riches, can also be consider a challenge for NVH performance. A longer wheelbase will require stiffer body and chassis structure to keep the ride comfort and squeak & rattle performance - to be more developed later on in the paper. At the same time Asian cars from Korea or Japan are sometimes outperforming the Europeans in terms of comfort. In future and in combination with the next evolution level of electrification and driving assistance the acceptable level of NVH annoyance will be reduced to a radically low threshold. In order to overcome the gap between this new threshold and current performances adjustments in vehicle specifications and the process to achieve those need to be implemented. The main focus is on powertrain noise, ride comfort and vibrations, rolling noise and wind noises and the overall NVH quality impression, e.g. of the door closing sound. The paper points out, which technical specifications are imperative for a good consumer reception and describes the processes that are needed for target achievement. |
Impact of Different Types of Glazing on Thermal Comfort of Vehicle Occupants | Due to intense peak summer temperatures and sunny summers in tropical countries like India etc., achieving the required thermal comfort of car occupants without compromising on fuel efficiency is becoming increasingly challenging. The major source of heat load on vehicle is Solar Load. Therefore, a study has been conducted to evaluate the heat load on vehicle cabin due to solar radiations and its impact on vehicle air-conditioning system performance with various combinations of door glasses and windscreen. The glasses used for this study are classified as green, dark green, dark gray, standard PVB (Polyvinyl Butyral) windscreen and PVB windscreen having infrared cut particles. For each glass, part level evaluation was done to find out the percentage transmittance of light of different wavelengths and heat flux through each glass. To verify the effectiveness of each glass, vehicle level air-conditioning system performance test was done in All Weather Chassis Dyno Facility for each retrofitted vehicle. To eliminate the effect of manufacturing variance while evaluating each retrofitted vehicle, only door glasses and windscreen were changed in the same vehicle keeping all other testing conditions such as ambient temperature, incident solar radiations, humidity and vehicle running pattern the same. The performance of each retrofitted vehicle was evaluated on the basis of its-soaking temperature, soaking time, grill temperature, and nose level temperature. On comparing the results of each configuration, the best door glass and windscreen configuration is proposed to improve the thermal comfort of the vehicle occupants. |
In-Situ Studies on the Effect of Solar Control Glazings on In-Cabin Thermal Environment in Hot and Humid Climatic Zones | Thermal comfort in a passenger cabin is the basic necessity of an occupant, especially in hot and humid climatic conditions. It is known that the reflective glazing solutions provide better thermal comfort inside the cabin due to significant reflection of IR part of solar radiation. However, in hot and humid climatic zones like India, significant reduction in heat load can also be achieved through cost effective solar control absorbing glazings. Thus, the present work aims to study the effect of solar control absorbing glazings on in-cabin temperatures and its impact on thermal comfort of the occupants in tropical climates. A combination of glazing sets with a range of solar energy transmission and absorption values is considered for the study. Indoor soak and cool tests are performed on a sedan model with multiple sets of solar control absorbing glass combinations. A constant ambient temperature of 38째C and solar radiation of 1000W/m2 are maintained throughout the tests. Wind speed is simulated for a vehicle running speed of 45 kmph. Net heat gain inside the cabin as a combination of various inward and outward loads of radiation through glazing is investigated. Accumulated heat is measured in terms of temperatures for comparison of various glazing sets. Reductions in heat loads are compared with experimental data of non-absorbing and reflective glazing sets available in literature. Best suitable combinations for front and back windshields, front and back side doors for the chosen vehicle are discussed in view of total solar energy transmission through the glazings and occupants thermal comfort. |
Evaluation of Laminated Side Window Glazing Coding and Rollover Ejection Mitigation Performance Using NASS-CDS | Occupant ejection has been identified as a safety problem for decades, particularly in rollover crashes. While field accident studies have repeatedly demonstrated the effectiveness of seat belts in mitigating rollover ejection and injuries, the use of laminated glass in side window positions has been suggested as a means to mitigate occupant ejection. Limited data is available on the field performance of laminated glass in preventing ejection. This study utilized 1997-2015 NASS-CDS data to investigate the reliability of the glazing coding variables in the database and determine if any conclusions can be drawn regarding the effect of different side window glazing types on occupant ejection. An initial query was run for 1997-2016 model year vehicles involved in side impacts to evaluate glazing coding within NASS-CDS. Sixteen individual cases were identified where the first-row side window glass was coded as both laminated and as in-place and holed, out-of-place and not holed, out-of-place and holed, or disintegrated from impact. NASS-CDS case summaries and photographs were reviewed and compared against original equipment manufacturer (OEM) specifications for the involved vehicles. The results demonstrated that the presence of laminated side window glass was incorrectly coded in 11 out of the 16 cases. The coding definitions were revised to query NASS-CDS for vehicles known to be equipped with standard or optional laminated glass in the first-row side windows based upon sources including the National Auto Glass Specifications (NAGS) database and vehicle manufacturer information (e.g., sales brochures, press releases, and other specifications). The new definitions were used in conjunction with the 16 previously identified side impact cases and found to correctly differentiate between the cases with and without laminated first-row side window glazing. Based upon this revised coding strategy, another NASS-CDS query was run to evaluate glazing type as it relates to rollover crashes involving 1997-2016 model year vehicles to determine the rate and frequency of front seat occupant ejection by glass type. This query resulted in a weighted 2,785,988 front seat occupants involved in a rollover, of which only 0.5% (13,640) occupants were in vehicles equipped with standard laminated front door window glass. Using the weighted occupants counts, there were 193 completely ejected and 277 partially ejected front seat occupants in vehicles equipped with standard laminated front door window glass; these numbers were based on unweighted samples of 10 or fewer. The sample sizes were too small to draw any statistically significant conclusions regarding ejection rates in rollover as a function of glazing type. The results of this study indicate that NASS-CDS glazing coding alone is not appropriate to identify the presence of laminated glass in specific vehicle window portals. This study also demonstrates that the resulting sample of field accidents is too small to assess the effectiveness of laminated glass in reducing the incidence of occupant ejection. The revised coding strategy may, however, be expanded with newer data and may be used in other databases such as Fatality Analysis Reporting System (FARS). It should be noted that, given the increased implementation of side curtain airbags in the vehicle fleet, it may become increasingly difficult to assess any individual contribution of laminated glass to occupant containment versus ejection. |
Evaluation of Functional Performance of Mechanism Using Multi Body Dynamics Simulation | The functional performance of the mechanism plays a vital role in attracting customer concentration towards the product. It is the first interface for interaction with the customer. Hence it is important to evaluate the functional performance at the time of the design phase itself in order to eliminate the possibility of an increase in proto-builds. The functional performance of a mechanism comprises parameters like, a mechanism should perform its function for which it is designed, with minimum effort required and ease in functionality. Evaluation of such parameters at the design stage involves many assumptions and this brings chance variables in the methodology. In order to eliminate these assumptions, a methodology has been developed using the multi-body dynamics (MBD) model of mechanisms like gear shifting mechanism and cabin door outer handle mechanism. The effort and displacement required to drive the mechanism were evaluated and a correlation of about 90% with the practical testing results was obtained. The same methodology was utilized to quickly optimize the existing design and reduce the effort and displacement required to drive the mechanism through the virtual model itself. |
An Analysis of the Effects of Ventilation on Burn Patterns Resulting from Passenger Compartment Interior Fires | Vehicle fire investigators often use the existence of burn patterns, along with the amount and location of fire damage, to determine the fire origin and its cause. The purpose of this paper is to study the effects of ventilation location on the interior burn patterns and burn damage of passenger compartment fires. Four similar Ford Fusion vehicles were burned. The fire origin and first material ignited were the same for all four vehicles. In each test, a different door window was down for the duration of the burn test. Each vehicle was allowed to burn until the windshield, back glass, or another window, other than the window used for ventilation, failed, thus changing the ventilation pattern. At that point, the fire was extinguished. Temperatures were measured at various locations in the passenger compartment. Video recordings and still photography were collected at all phases of the study. Although the fire origin and source were known, the vehicle burn patterns were analyzed and conclusions drawn based on the post-fire evidence regarding: ability to determine a window was open during the fire, which window was open, the effect the open window had on burn patterns and burn damage, and the ability to determine the fire origin. Thermocouple readings were plotted and analyzed post-test to study temperature characteristics during the burn tests. |
A Development and Evaluation of Optimal Fingerprint Authentication Algorithm in Vehicle Use Environment | Hyundai Motor Company mass-produced the world's first fingerprint entry and start system. This paper is a study on the evaluation method to develop and verify the optimal fingerprint authentication algorithm for vehicle usage conditions. Currently, fingerprint sensors and algorithms in the IT industry have been developed for the electronic devices, and are not suitable for the harsh environment of the vehicle and the vehicle life cycle for more than 10 years. In order to optimize the fingerprint sensor and algorithm for the vehicle, this study consisted of 3way test methods. As a result, the fingerprint system could be optimized for the vehicle and the recognition rate and security could be optimized according to the sensor authentication level. Through this study, the door handle recognition rate was improved by 25% and the start button recognition rate by 10%, and the fingerprint entry and start system was mass-produced with security level that satisfies the immobilizer regulations. |
Robustness Design to Avoid Noise on Exterior Handle System | Squeak and rattle are two undesirable occurrences during component operation and during vehicle driving condition, resulting in one of the top complains from costumers. One common grievance could happen during the user exterior handle operation and during side door closing. The exterior handle system during the operation could generate a squeak between interface parts, if materials and geometric tolerances was not been carefully designed. Also, vibration generated during door closing effort, might generate squeak between parts since the reinforcement for exterior handle touches the outer sheet metal internally. For this reason several guidelines might be included to avoid potential noise condition for this system during vehicle lifetime as correct material reduce friction between parts, taking into consideration the geometric condition between parts. Plus, coupling system on handles two pieces should also be evaluated to avoid squeak during use. Not less important, if required anti-shock material system may be applied to eliminate a clash produced between parts during excessive vibration. It is extremely important to evaluate the environment that the vehicle will be exposed since the correct material application also depend on this factor. Design parameters as materials used to produce parts, dimension geometric data and a robust technique of attachment must be analyzed. Correct material selection and tools like Dimensional Variation Analysis may be taken to identify and optimize the design to avoid noise and minimize cost. |
Coating on Striker: Low Coefficient of Friction to Avoid Creak Noise | The unpleasant noise (creak) originated from latch-striker interaction, perceived mainly when the vehicle is submitted to uneven road conditions is generated by stick-slip phenomenon mainly due materials incompatibility of contact surfaces. Generally, eliminate this incompatibility is unfeasible due technical and/or economics constrains; this scenario makes it necessary to act in other fronts to neutralize the effects of that incompatibility. Reduce the coefficient of friction from one of contact surfaces is an alternative that can be easily applied at striker through a thin thickness coating with that property. |
Practical Design Considerations for Lightweight Side Window Applications | Automotive manufacturers are requiring lightweight materials, including glazing materials to improve vehicle fuel economy and meet government mandates. Taken as a group, the area of four side windows is comparable to that of a windshield, and, therefore, can offer significant weight reduction opportunities. As glass thickness is reduced, the acoustic and stiffness properties of the glazing change. Newer developmental interlayer materials have demonstrated the capability for overcoming the reduction in performance to maintain the properties of the original heavier constructions. |
Modeling and Numerical Analysis of Automotive Aerodynamic Noise Generation and Transmission Considering Equivalent Nonlinear Sealing | Aerodynamic noise transmits through automotive window, causing great adverse influence on comfortability and noise-vibration-harshness (NVH) performance. However, the complicated external turbulent air flow, as well as the internal metal-rubber nonlinear sealing constraint, makes the mechanism of aerodynamic noise generation and transmission very difficult. Regarding the complex exterior aerodynamics-induced load and nonlinear metal-rubber interaction and constraint, an efficient two-step numerical prediction method is presented in order to study the mechanism of its generation and transmission. The first step uses the commercial ANSYS-Fluent computational fluid dynamics (CFD) analysis based on the shear stress transport (SST) - turbulence kinetic energy (k) - the rate of dissipation of turbulence kinetic energy 琯 (epsilon) model and Lighthill?셲 noise source theory. For low Mach number and high Reynolds number flow like the flow around a vehicle body, dipole source is regarded as the dominant contribution and can be obtained by the broadband noise source model. Exterior turbulent flow field of a full-scale automotive is established and near-field sound power distribution of automotive window has been obtained, which are both subsequently input to the acoustic model to investigate the noise generation mechanism. The second step consists of the numerical prediction of noise transmission through automotive window. Nonlinear spring-based surrogate model for seal nonlinear constraint is proposed and verified by modal experiment. Based on SAE J1400 reverberant-anechoic measurement standard, a numerical prediction model of the sound transmission loss (STL) is constructed using commercial vibro-acoustic solver Actran. New automotive window structural design by non-uniform density distribution is proposed to optimize the STL property. The present methodology of STL modeling and numerical prediction provides valuable instructions for performance optimization of automotive door under high speed driving condition. |
?쏷aguchi Customer Loss Function??Based Functional Requirements | Understanding customer expectations is critical to satisfying customers. Holding customer clinics is one approach to set winning targets for the engineering functional measures to drive customer satisfaction. In these clinics, customers are asked to operate and interact with vehicle systems or subsystems such as doors, lift gates, shifters, and seat adjusters, and then rate their experience. From this customer evaluation data, engineers can create customer loss or preference functions. These functions let engineers set appropriate targets by balancing risks and benefits. Statistical methods such as cumulative customer loss function are regularly applied for such analyses. In this paper, a new approach based on the Taguchi method is proposed and developed. It is referred to as Taguchi Customer Loss Function (TCLF). The ?쏷aguchi Quality Loss Function (TQLF)??methodology has been used primarily to improve quality from a manufacturing standpoint, giving engineers a way to understand how process variation affects customer satisfaction. In the proposed ?쏷aguchi Customer Loss Function (TCLF)??methodology, a similar analogy is applied for developing requirements on the design such that variation in customer preference is accounted for. Also, trade-offs can be made with other business constraints while keeping the customer dissatisfaction to minimum. Example problems are presented to demonstrate its simplicity and its potential for understanding customer clinic data. |
Eleven Instrumented Motorcycle Crash Tests and Development of Updated Motorcycle Impact-Speed Equations | Eleven instrumented crash tests were performed as part of the 2016 World Reconstruction Exposition (WREX2016), using seven Harley-Davidson motorcycles and three automobiles. For all tests, the automobile was stationary while the motorcycle was delivered into the vehicle, while upright with tires rolling, at varying speeds. Seven tests were performed at speeds between 30 and 46 mph while four low-speed tests were performed to establish the onset of permanent motorcycle deformation. Data from these tests, and other published testing, was analyzed using available models to determine their accuracy when predicting the impact speed of Harley-Davidson motorcycles. The most accurate model was the Modified Eubanks set of equations introduced in 2009, producing errors with an average of 0.4 mph and a standard deviation (SD) of 4.8 mph. An updated set of Eubanks-style equations were developed adding data published since 2009, and advancing from two equations (pillars/axles and doors/fenders) to four equations (axles, pillars/bumpers, doors, and fenders). When applied to the subject tests, the newly developed set of equations produced an average error of 3.5 mph (SD = 4.3 mph). With respect to all available data (N = 99), the equations produced an average error of 0.1 mph and a standard deviation of 5.8 mph. The errors were also analyzed for each of the four equations developed here, and confidence intervals offered. This research, which represents the first detailed analysis of Harley-Davidson motorcycles??collision response, indicates they behave in a manner similar to previously tested motorcycles. Further, the equations developed and presented here give accident investigators a refined method for estimating the impact speed of an upright motorcycle, Harley-Davidson or otherwise, having struck an automobile with its front tire. |
Regression Analysis: A Geometric Perspective | Regression analysis is perhaps one of the most widely used statistical tools in six-sigma projects. The reason for its popularity is that it provides a formal evaluation of the relationship between one dependent variable and one or more predictors. The ordinary least squares (OLS), which is a method for estimating the parameters of the linear regression model, has some numerical properties that can be easily understood by looking at them in a geometric manner. In this paper, we discuss the fundamentals of both simple and multiple regression analysis from a geometric perspective. This approach offers an intuitive understanding of some concepts that otherwise would require a background in statistical mathematics and differential calculus. One of the topics covered in this paper is multicollinearity, whose consequences are not well understood by many practitioners. A practical example drawn from the automotive industry (body exterior quality) is used to clarify the basic notions that appear throughout the paper. This example consists of a regression analysis made over a sample of vehicles in an attempt to explain the level of customer's complaints regarding side door closing effort (dependent variable) by the actual closing effort measured in a laboratory using a standard procedure (independent variable). It is well known that closing effort, in turn, is also highly correlated with the compression load deflection (CLD) of the door seals, meaning that including both variables as predictors in the same model would produce unreliable estimates of the parameters. Unfortunately, many quality engineers disregard the effects of multicollinearity when they perform this kind of analysis. This paper is intended to draw attention to these issues in a user-friendly way. |
Standard for Safety Glazing Materials for Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land Highways - Safety Standard | Specifications, test methods, and usage provisions for safety glazing materials used for glazing of motor vehicles and motor vehicle equipment operating on land highways. |
Automotive Safety Glazing Materials | This SAE Recommended Practice is a guidance document, which covers current safety glazing materials applicable for use in motor vehicles and motor vehicle equipment. Nominal specifications for thickness, flatness, curvature, size, and fabrication details are included. This guidance document does not precede or replace customer specifications and requirements. |
Automotive Safety Glazing Materials | This SAE Recommended Practice is intended to cover current safety glazing practice applicable to safety glazing for use in motor vehicles and motor vehicle equipment. Nominal specifications for thickness, flatness, curvature, size, and fabrication details are included principally for the guidance of body engineers and designers. |
Analysis of Damage Caused to Vehicle Body Panels by Impacting Hail and Various Tools and Objects | On the 25th December 2011 there was a hail storm in the state of Victoria, Australia, which caused approximately AU$712 million worth of damage. Some of this damage was caused to passenger vehicles. The authors conducted a number of inspections of hail-damaged vehicles as a result of insurance claims being disputed or rejected on the basis that some, or all, of the alleged hail damage was not created by hail but instead created intentionally by the vehicles' owners with the use of different tools and/or objects. As a result of the inspections and investigations of potentially fraudulent claims, the authors conducted a total of 119 tests designed to replicate damage caused to vehicle body panels by impacting hail and to recreate claimed hail damage by using tools and other objects. To do so, the authors created two sizes of hail: 횠20 mm and 횠40 mm hail. A total of 15 impact tests were conducted with 횠20 mm hail. The impact speed for the 횠20 mm hail varied between 75 km/h and 144 km/h, with the average being 113 km/h. A total of 50 impact tests were conducted with 횠40 mm hail. The impact speed for the 횠40 mm hail varied between 66 km/h and 133 km/h, with the average being 101 km/h. The testing impact speeds were generally higher than the terminal velocities of the corresponding hail, so the damage observed is expected to be an over estimation of the actual damage caused by hail. The hail was projected at the test vehicle using a purpose-built projectile launching device that used a sling-like mechanism to project hail in a horizontal direction at a test vehicle. The test vehicle was a white-colored 2001 model Holden Commodore with non-metallic paint. The body panels tested were: bonnet, roof, boot, all four doors, the vehicle pillars and cant rail. High speed cameras were used to determine the impact speed of the hail. Damage was photographed and recorded. In addition to impacting the vehicle with hail, a number of different tools and objects were used to recreate man-made damage. Tools and objects used were: claw hammer (conventional), welding hammer, ball-peen hammer, mason hammer, lead ball sink in a sock, golf ball in a sock, ratchet, breaker bar, crowbar and center punch. The conducted tests revealed the following findings: 1. hail impacting the vehicle body panels will not scratch or mark the paint but the paint may chip if hail impacts the vehicle near a fold or edge of a panel; 2. dents caused by hail will cause the light to move smoothly and continuously across the dent and the light will not "break" or crease; 3. where dents were caused by tools and objects the light will crease into multiple (two or more) distinct areas as it passes over the dent; 4. scratches and/or markings in the paint were identified on dents caused by tools and objects; 5. folds and curves on the panels did not affect the size of the dent caused to the panel; using the same tool and force to impact two different body panels (A-pillar and roof) resulted in dents that were very similar in physical appearance; 6. for the same impact speed the larger 횠40 mm hail caused more damage than the 횠20 mm hail; and 7. for the same size hail the higher impact speed hail caused more damage. |
Eleven Instrumented Motorcycle Crash Tests and Development of Updated Motorcycle Impact-Speed Equations | Eleven instrumented crash tests were performed as part of the 2016 World Reconstruction Exposition (WREX2016), using seven Harley-Davidson motorcycles and three automobiles. For all tests, the automobile was stationary while the motorcycle was delivered into the vehicle, while upright with tires rolling, at varying speeds. Seven tests were performed at speeds between 30 and 46 mph while four low-speed tests were performed to establish the onset of permanent motorcycle deformation. Data from these tests, and other published testing, was analyzed using previously published equations to determine their accuracy when predicting the impact speed of Harley-Davidson motorcycles. The most accurate model was the Modified Eubanks set of equations introduced in 2009, producing errors with an average of 0.4 mph and a standard deviation (SD) of 4.8 mph. An updated set of Eubanks-style equations were developed adding data published since 2009, and further partitioning from two equations (pillars/axles and doors/fenders) to four equations (axles, pillars/bumpers, doors, and fenders). When applied to the subject tests, the newly developed set of equations produced an average error of 3.5 mph (SD = 4.3 mph). With respect to all available data (N = 99), the equations produced an average error of 0.1 mph and an SD of 5.8 mph. The errors were also analyzed for each of the four equations developed here, and confidence intervals offered. This research, which represents the first detailed analysis of Harley-Davidson motorcycles??collision response, indicates they behave in a manner similar to previously tested motorcycles. Further, the equations developed and presented here give accident investigators a refined method for estimating the impact speed of an upright motorcycle, Harley-Davidson or otherwise, having struck an automobile with its front tire. |
Prediction of Sound Transmission through Door Seals Using the Hybrid FE-SEA Method | During the last decades, the application of noise control treatments in vehicles has targeted the main noise transmission paths to interior noise. These paths include vehicle body panels such as dash panel, doors and floor. Many improvements have been achieved on these areas, and, as a consequence, other transmission paths once thought as secondary became relevant. This is the case of the sound transmission through door seals and others sealing elements at mid and high frequencies. In this paper, the interest lies on the prediction of the transmission loss of door seals. A full nonlinear deformation/contact analysis is used to estimate the deformed geometry of a door seal in real conditions. The geometry is then used in a vibro-acoustic analysis to predict the in-situ transmission loss of the seal using a local Hybrid FE-SEA model. The channel between the door and the car structure where the seal is located is also included in the analysis. Results for the transmission loss are compared with experimental data, showing a good correlation. It is also shown that the channel is an important element of the analysis and must be taken into account. |
Innovative Robust Solutions for Lean Manufacturing in Automotive Assembly Processes | The article presents an innovative approach to the implementation of a robust design optimization solution in an automobiles assembly process. The approach of the entire project is specific to the 6 Sigma optimization process, by applying the DMAIC cycle integrated in a robust engineering approach for rendering lean the final product assembly process. According to the improvement cycle, the aspects specific for such a process are presented sequentially starting with the ?쏡efine??phase for presenting the encountered problem and continuing with the presentation of the scope of the project and its objectives. The ?쏧mprovement??cycle phase is applied by the analysis of the monitored 6 Sigma metrics (defined during the previous ?쏮easure??phase and the cause and effect analysis, done during a brainstorming meeting developed during the ?쏛nalyze??phase). There follows a proposal for the innovative robust solution by which the assembly process is optimized. Therefore, we propose the final assembly of already painted doors on the already assembled cars with a special work-holding which is easy to handle by the human operator. The automation of designed and implemented solutions provides features of error proofing for the assembly process in the case in which the doors are not located accordingly on the work-holding locating elements, which may lead to various inconveniences during the assembly on the vehicle and/or some faults of the door quality, such as scratches or deformations because of the impacts. The initially presented process indices, for the not yet optimized process are finally evaluated after the implementation of the innovative solution for a comparative study of the initial monitoring results and after the implementation of the proposed corrective solution. This underlines the critical conclusions that are induced during the ?쏞ontrol??phase. The final conclusions point to the corrective / preventive actions for a sustainable and reliable optimization, which give the maximal process its overall efficiency. |
Advances in Vehicular Ad-Hoc Networks: Developments and Challenges | A Vehicular Ad Hoc Network (VANET) is a non-infrastructure based network that does not rely on a central administration for communication between vehicles. The flexibility of VANETs opens the door to a myriad of applications; however, there are also a number of computer communication challenges that await researchers and engineers who are serious about their implementation and deployment. This book tackles the prevalent research challenges that hinder a fully deployable vehicular network. This unique reference presents a unified treatment of the various aspects of VANETs and is essential for not only university professors, but also for researchers working in the automobile industry. Topics include: Architecture of vehicular ad hoc networks Communication technologies in vehicular applications Cooperative collision avoidance Geographic routing in vehicular ad hoc networks IEEE 802.11g and IEEE 802.16e technologies Information sharing in VANETs Infrastructures in vehicular communications Mobility and traffic model analysis Opportunistic networking Routing protocols in vehicular ad hoc networks |
Kiekert unveils automatic-door tech for autonomous vehicles | A new electronic side door latch is the prelude to vehicle side doors that automatically open and close on command. ?쏰ur endgame is about providing a system in which the side doors automatically open when an autonomously-driven car arrives for passengers,??said Hector Verde, Director of Product Development for the Americas at Kiekert. Those doors would also close automatically after the occupants are in the vehicle. All this could happen with just the push of a button or sensor recognition, he added. |
Researchers Uncover New Way to Control Information by Mixing Light and Sound | A Yale lab has developed a new, radio frequency processing device that allows information to be controlled more effectively, opening the door to a new generation of signal processing on microchips. |
Lightweight door module aims to trim vehicle weight | A new ultralight door architecture nets a 42.5% weight savings compared to a current production door-and that's enough to put this lightweight concept in an enviable position. ?쏷his lightweight door module has a great opportunity to be commercialized. It's not just high-tech. It's also at the right cost,??said Reuben Sarkar, Deputy Assistant Secretary for Transportation, Energy Efficiency and Renewable Energy at the U.S. Department of Energy. |
Automobile and Motor Coach Wiring | This SAE Recommended Practice covers the application of primary wiring distribution system harnesses to automotive, and Motor Coach vehicles. This is written principally for new vehicles but is also applicable to rewiring and service. It covers the areas of performance, operating integrity, efficiency, economy, uniformity, facility of manufacturing and service. This practice applies to wiring systems of less than 50 V. |
Passengers First Light Truck - A Modern Take on a Narrow Wake | Individuals in the United States consume twice as much energy as those in any other region. Solitary workday commutes in light vehicles are the leading reason for this difference. An electric vehicle design is proposed to help catalyze more social, higher occupancy, commuting habits - through application of existing technology. Performance criteria are: 1) attract passengers to the suburban front yard at 6:30 AM, 2) match market leading crash test performance, cargo capability, and sense of freedom, and 3) deliver easier parking, better acoustics and better passenger mile efficiency. A vehicle as a rolling event venue determines a large windscreen, side-by-side upright seating arrangements, and acoustic excellence -an experience where there are only good seats. These requirements force a decision to close the wake along a vertical line to form a narrow wake. The chassis is platform batteries with dual motor electric rear drive and undetermined front drive. Findings: 1 Narrow wake synergies include: a) cargo loading on a tailgate ramp to a low 0.3m (12 inch) high load floor through a 0.8m (32 inch) wide opening - as a controlled event using an onboard powered trolley, b) passengers more safely located, and c) thick rear doors that pivot concentric with the rear axle, with no chance of damaging adjacent objects. 2 A consistent driver?셲 eye location, as datum, provides better forward visibility past the A-Pillar and more consistent relationships between driver, passengers and vehicle safety and content delivery systems, when compared to location off fixed pedals at the firewall. 3 Collateral benefits of the eye datum include large section B-Pillars, dual diagonal cooling circuits that apply full cooling power as the sun clocks, and a smooth transition to self-driving operation. |
Intrusion Resistance of Safety Glazing Systems for Road Vehicles | This SAE Recommended Practice specifies an intrusion resistance test method for glazing systems installed in motor vehicles. Intrusion resistance performance is determined not solely by the glazing but also by the glazing attachment to the vehicle and by the vehicle structure. Therefore, the glazing/attachment/vehicle structure must be tested as a single unit. This test determines intrusion resistance only. The test applies to those materials that meet the requirements for use as safety glazing materials as specified in ANSI/SAE Z26.1 or other applicable standards. The test applies to all installation locations. |
A Test Method and Simulation Study of PMMA Glazing on Motion Deviation | For achieving vehicle light weighting, the motion deviation is calculated for substitution of PMMA glazing for inorganic glass. In this paper, a test method is proposed to measure and calculate the motion deviation of the dual-curvature glass. To simulate the dual-curvature glass, the torus surface is fitted with least square method according to the window frame data, which are measured by Coordinate Measuring Machine. By using this method, the motion deviation of PMMA glazing and inorganic glass can be calculated, which can not only validate the effectiveness of motion simulation, but also compare the performances. The results demonstrate that the performance of PMMA glazing is better than that of inorganic glass and the simulation results is validated. |
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