Browse Topic: Bumpers, fasciae and grilles

Items (385)
To reduce aerodynamic drag during real-world driving, it is essential to consider the effects of crosswinds. The yaw angle dependence of aerodynamic drag is known to vary based on the vehicle body type; however, there are limited studies on the physical mechanisms underlying this difference, particularly through detailed visualizations of the flow structure and its response to yaw angles. This study investigates the differences in flow structures between an SUV and a notchback to understand the mechanism responsible for the variation in yaw angle dependence of CD under quasi-steady yaw angle conditions. Numerical simulations and wind tunnel tests were conducted for both the SUV and the notchback at yaw angles of 0°, 2°, and 5°. Crossflow and total pressure were employed as indicators for visualizing the flow structure, with a focus on the wake behind the vehicle in the visualizations of the wind tunnel tests and simulations. Additionally, isosurfaces of the crossflow velocity magnitude
Nakata, AkihiroOkamoto, SatoshiNishida, ShuheiMorikawa, YosukeNakashima, Takuji
The metal inert-gas (MIG) welding technique employed for aluminum alloy automotive bumpers involve a complex thermo-mechanical coupling process at elevated temperatures. Attaining a globally optimal set of model parameters continues to represent a pivotal objective in the pursuit of reliable constitutive models that can facilitate precise simulation of the welding process. In this study, a novel piecewise modified Johnson-Cook (MJ-C) constitutive model that incorporates the strain-temperature coupling has been proposed and developed. A quasi-static uniaxial tensile model of the specimen is constructed based on ABAQUS and its secondary development, with model parameters calibrated via the second-generation non-dominated sorting genetic algorithm (NSGA-II) method. A finite element simulation model for T-joint welding is subsequently established, upon which numerical simulation analyses of both the welding temperature field and post-welding deformation can be conducted. The results
Yi, XiaolongMeng, DejianGao, Yunkai
Polypropylene has been the plastic traditionally used in the manufacture of bumpers. Composite materials have been presented as an alternative due to lightness and sustainability. This article presents a composite of polyester resin and jute fiber fabric as an innovative alternative to be studied for the manufacture of automotive bumpers. Composite material was manufactured for characterization. It was used as matrix the terephthalic polyester resin, unsaturated and pre-accelerated, and the catalyst MEK V388 for curing the composite. The chosen reinforcement was the jute fiber fabric. Silicone molds with dimensions according to ASTM 3039 were used to manufacture specimens, and subsequent tensile strength test to determine properties and compare with literature data. The composite with jute fiber reinforcement with alignment 0°/0°/0° was evaluated as viable for the application in car bumpers, having its value of tensile strength surpassed that of the composite reinforced by jute fiber
Dias, Roberto Yuri CostaSoares, Rafael Vilhenade Mendonca Maia, Pedro Victordos Santos, Jose Emilio MedeirosMiranda, Igor Ramon SinimbúJunior, Waldomiro Gomes PaschoalFujiyama, Roberto Tetsuo
In recent decades, thermoplastics have become fundamental materials for the automotive industry, due to characteristics such as low density and increased possibility of manufacturing parts into complex geometries. Correlate the mechanical behavior of parts made with these materials, between virtual and physical testing, still poses a challenge that can be explained by the inherent nature of polymeric compounds, which generally exhibit a complex microstructural composition. This study uses a Bumper Grille made of Acrylonitrile Styrene Acrylate (ASA) as case study. This part is a fundamental external vehicle component, not only for safety criteria, but also for consumer satisfaction. To analyze the structural behavior of a vehicle components such as a Grille, Computer Aided Engineering (CAE) tools with the Finite Element Method (FEM) are commonly applied, in which a good understanding of the analysis setup and physical properties used to define the model are essential. For models built
Ferreira, Gabriel RamosSouza Silva, PauloSoares, Annelise Heidrich PietroMaciel, Ronei SantosCarvalho, Gimaézio GomesSanchez, Jorge Romero
In the realm of commercial vehicle design, enhancing the durability of bumpers and headlamps is paramount for ensuring safety and reducing maintenance costs. This study explores the development of a lightweight bumper design with optimized resonance frequency to improve the durability of these critical components. The research focuses on innovative design techniques to achieve a balance between weight reduction and structural integrity. The primary objective is to minimize the impact forces transmitted to the bumper and headlamp assemblies during vibrations. By employing finite element analysis (FEA) and experimental validation, the study identifies the optimal resonance frequency that mitigates the risk of resonance-induced damage. Additionally, the study examines the influence of geometric modifications on the bumper’s performance. Various design iterations are analyzed to determine the most effective configuration for enhancing durability while maintaining compliance with industry
Pandey, SudheerGanesan, Balaji
Automotive radar plays a crucial role in object detection and tracking. While a standalone radar possesses ideal characteristics, integrating it within a vehicle introduces challenges. The presence of vehicle body, bumper, chassis, and cables in proximity influences the electromagnetic waves emitted by the radar, thereby impacting its performance. To address these challenges, electromagnetic simulations can guide early-stage design modifications. However, operating at very high frequencies around 77GHz and dealing with the large electrical size of complex structures demand specialized simulation techniques to optimize radar integration scenarios. Thus, the primary challenge lies in achieving an optimal balance between accuracy and computational resources/simulation time. This paper outlines the process of radar vehicle integration from an electromagnetic perspective and demonstrates the derivation of optimal solutions through RF simulation.
Rao, SukumaraM K, Yadhu Krishnan
A and B stiffness coefficients to model the frontal stiffness of vehicles is a commonly used and accepted technique within the field of collision reconstruction. Methods for calculating stiffness coefficients rely upon examining the residual crush of a vehicle involved in a crash test. When vehicles are involved in a collision, portions of the crushed vehicle structures rebound from their maximum dynamic crush position. Once the vehicle structures have finished rebounding, the remaining damage is called the residual crush. A problem can arise when the plastic bumper cover rebounds more than the vehicle's structural components, resulting in an air gap between the structural components and the plastic bumper cover. Most modern New Car Assessment Program (NCAP) tests quantify crush in the test reports based on the deformed location of the plastic bumper cover and not the structural components behind the plastic bumper cover. This results in an underreporting of the actual residual crush
Neal, JosephLipscomb, MatthewFunk, Charles
Passenger vehicle bumpers are designed to reduce collision damage. If colliding bumpers are not vertically aligned, their effectiveness is reduced and the resulting damage increases. Two bumpers of similar static design heights may become misaligned due to bumper dive caused by one or both vehicles pitching forward due to braking. Previous researchers have quantified bumper dive and how it changed with passenger vehicle designs. Currently there are limited data available to quantify the mean, variance, and distribution of bumper dive for modern ABS-equipped vehicles. We conducted maximum braking tests using 3 late-model minivans/CUVs (crossover utility vehicles) and 9 late-model sedans on contiguous dry asphalt and concrete road surfaces. Between 16 and 23 tests were conducted for each vehicle and all tests were conducted from an initial speed of about 65 km/h (40 mph). A laser distance sensor mounted to the front bumpers measured bumper height throughout each test. Overall, we found
Young, StevenGish, RussellSiegmund, Gunter P.
MSIL (Maruti Suzuki India Limited), India’s leading carmaker, has various SUVs (Sports Utility Vehicle) in its model lineup. Traditionally, SUVs are considered to have a bold on-road presence and this bold design language often deteriorates aerodynamic drag performance. Over the years, the demand for this segment has significantly grown, whereas the CAFE (Corporate Average Fuel Economy) norms have become more stringent. To cater this growing market demand, MSIL planned for two new SUVs: (1) New BREZZA - A bolder design with similar targeted aerodynamic performance compared to its predecessor (BREZZA-2016) and (2) FRONX - A new cross-over SUV vehicle targeted best-in-class aerodynamic performance in this category at MSIL. This paper illustrates the aerodynamic development process for these two SUVs using CFD (Computational Fluid Dynamics) and full scale WTT (Wind Tunnel Test). During the initial stages, the bolder design of the New BREZZA (2022) deteriorated the aerodynamic drag of the
Dey, SukantaBajpai, DeveshKumar, ChandanRegin, Felix
Anyone who has ever tried to pack a family-sized amount of luggage into a sedan-sized trunk knows this is a hard problem. Robots struggle with dense packing tasks, too. For the robot, solving the packing problem involves satisfying many constraints, such as stacking luggage so suitcases don’t topple out of the trunk, heavy objects aren’t placed on top of lighter ones, and collisions between the robotic arm and the car’s bumper are avoided.
LiDAR stands for Light Detection and Ranging. It works on the principle of reflection of light. LiDAR is one among the other sensors like RADAR and Camera to help achieve a higher level (Level 3 & above) of Autonomous driving capabilities. LiDAR, as a sensor, is used to perceive the environment in 3D by calculating the ‘Time of flight’ of the Laser beam transmitted from LiDAR and the rays reflected from the Object, along with the intensity of reflection from the object. The frame of perception is plotted as a point cloud. LiDAR is integrated in front of the vehicle, precisely in the grill of the car having a high vantage point to perceive the environment to extract the best possible sensor performance. LiDAR sensor needs to be held within the front panel cutout with uniform gap and flush condition. However, due to tolerance reasons it may have following issues: Sensor functional degradation will happen if it is not aligned properly at the center to the cutout, because the view cones
Pratap, AmitRangarej, Sanjeev
In recent years, the number of electric vehicles (EVs) has grown rapidly, as well as public interest in them. However, the lack of sufficient range is one of the most common complaints about these vehicles, which is particularly problematic for people with long daily commutes. Thus, this article proposed a solution to this problem by installing micro wind turbines (MWTs) on EVs as a range extender. The turbines will generate electricity by converting the kinetic energy of the air flowing through the MWT into mechanical energy, which can have a reasonable effect on the vehicle aerodynamics. The article uses mathematical modelling and numerical analysis. Regarding the modelling, a detailed EV model in MATLAB/SIMULINK was developed to analyze the EV performance using various driving cycles in real time. In terms of numerical analysis, a detailed computational fluid dynamics (CFD) model has been implemented on a sample EV (Kia Soul) and an MWT using the Moving Reference Frame (MRF) method
Ebaid, MunzerShahin, Zin Al Abdin A. E.Alshawabkeh, Mohammad M. D.
The automotive sector is evolving both globally and as well as in India. The Indian customer’s expectations from an automobile are also evolving at fast pace. This is resulting in a continuous shrinkage of the time available for vehicle development. To meet customers’ expectation of superior cabin thermal comfort it is important to predict cabin cooling performance at early stage. This can be achieved through thermal simulation. Existing studies of cabin thermal simulation explained the method of co-simulation. Wherein, Input for the cabin was used a grill air temperature which was obtained from the physical test. It showed good correlation for the cabin inside air temperature with actual test. However, cabin cooling performance does not only depend on cabin structure & layout but also, affected by AC system & its component level performance. AC systems and components were not considered in previous studies. As a result, replacing or modifying the AC system components does not allow us
Bhangale, ShekharUmbarkar, ShriganeshKumar, MukeshSaha, AniketGakhar, SahilKhan, Majid
Vehicles with active grille shutter (AGS) systems often have bypass and leakage situations that influence the aerodynamic effectiveness and characteristics of the AGS. Precise knowledge of these characteristics, that is, the functional relationship between drag, cooling airflow rate, and degree of opening of an AGS is a prerequisite for optimum aero-thermodynamic integration into the overall vehicle. However, relatively little is yet known about the interaction of bypass and leakage flows with AGS systems. The present work therefore investigates how a bypass affects the aerodynamic characteristics of AGS. The starting point is a recently developed theory that allows an analytical prediction of the aerodynamic behavior of AGS based on the opening characteristic. This theoretical approach is first extended to the case with bypass and matched against experimental data from a real vehicle with AGS bypass configuration. The comparisons between theory and experiment lead to two semiempirical
Wolf, Thomas
Toyota's luxury arm concurrently introduced the all-new, three-row 2024 Lexus TX and the long-awaited redesign of the rugged Lexus GX, also a '24 model. Both were met with enthusiasm at a reveal in Austin, Texas, over what Lexus is calling the new “unified spindle,” an evolution of the spindle grille that has been divisive since it appeared on the 2012 GS sedan. In a nifty trick, engineers have figured out how to include ADAS sensors in the grille without having asymmetrical blocks interrupt the bars. Dealers and more mainstream customers will be most interested in the TX, as Lexus Group Vice President Dejuan Ross said buyers have been clamoring for a new three-row SUV. And there's good reason: 70% of all full-size SUVs sold in America have a third row. For midsize SUVs, the number jumped from 6% to 10% from 2016 to 2022, according to J.D. Power.
Clonts, Chris
Nearly every company in the world performs some level of quality inspection on their products before delivering them to customers. If you’re in the downloadable software business, this might involve making sure the product is bug-free and easy to use. But in the realm of physical products, the appearance of the product is nearly as important as its functionality. Would you want to purchase a new car that has scratches on the bumper or hubcaps? What if there was a crack in the windshield? From large to small, the same is true of many other items including appliances, laptops, cellphones, watches, and earbuds.
Injury assessment by using a whole-body pedestrian dummy is one of the ways to investigate pedestrian safety performance of vehicles. The authors’ group has improved the biofidelity of the lower limb and the pelvis of the mid-sized male pedestrian dummy (POLAR III) by modifying those components. This study aims to evaluate the biofidelity of the whole-body response of the modified dummy in full-scale impact tests. The pelvis, the thigh and the leg of POLAR III have been modified in a past study by optimizing their compliance by means of the installation of plastic and rubber parts, which were used for the tests. The generic buck developed for the assessment of pedestrian dummy whole-body impact response and specified in SAE J3093 was used for this study. The buck representing the geometry of a small family car is comprised of six parts: lower bumper, bumper, grille, hood edge, hood and windshield. Tests were performed by conforming to SAE J2782 that specifies test conditions to
Asanuma, HiroyukiBae, HyejinNakamura, HidetoshiGunji, YasuakiNagashima, AkikoMori, Fumie
As the AVN display in the car interior becomes larger and located above the center fascia, the driver's visual visibility is becoming important. In addition, since an expensive touch sensor is installed, a transparent electrode cost reduction technology for a display touch sensor that can replace an indium material, which is an expensive rare metal, is required. In this paper, we developed new transparent electrode materials and manufacturing methods for the touch sensor film which light reflectance is low and flexible without a separate low-reflection multi-layer, so that the design freedom is high and the material cost is low. By optimizing the amount of fluorine doping ratio in tin oxide, excellent electrical conductivity and high optical transmittance are secured, and the surface reflectance is reduced by adjusting the diameter and length of the silver nanowire. As a result, it was shown that the AVN display image and font readability was improved. In addition, we verified that the
Kweon, KyoungchunHong, Seungchan
The coefficient of restitution is utilized in various methods for determining the change in velocity (delta-V) associated with a vehicle collision event. Additionally, for a given delta-V, the magnitude of vehicle acceleration varies with different collision pulse durations. Collision restitution and duration parameters are thus considered by both accident reconstructionists and biomechanists in the investigation of vehicle collision severity and occupant injury potential. Because of the uniqueness of individual vehicle designs, it is difficult to determine a collision’s specific coefficient of restitution and crash pulse duration. Accident reconstructionists often estimate the values of these parameters based on staged crash tests. Prior studies involving low-speed collisions have sought to determine correlations between restitution and collision characteristics and have established equations to assist in estimating restitution. Most of these equations are based around the correlation
Olberding, JosephPetroskey, KarlaLeipold, Tara
The automotive industry is moving towards larger SUVs and also electrification is a need to meet the carbon neutrality target. As a result, we see an increase in overall gross vehicle weight (GVW), with the additional weight coming from the HV battery pack, electric powertrain, and other electrical systems. Tow-eye is an essential component that is provided with every vehicle to use for towing during an emergency vehicle breakdown. The tow-eye is usually connected to the retainer/sleeve available in the bumper system and towed using the recovery vehicle or other car with towing provision. Therefore, the tow-eye should meet the functional targets under standard operating conditions. This study is mainly for cars with bumper and tow-eye sleeves made of aluminum which is used in the most recent development of vehicles for weight-saving opportunities. Tow-eye systems in aluminum bumpers are designed to avoid any bending or buckling of the sleeve during towing for whatever the GVW loads. So
Fahir, AhamedChoudhari, SatishMichalowski, Krzysztof
In the past decades, automotive structure design has sought to minimize its mass while maintaining or improving structural performance. As such, topology optimization (TO) has become an increasingly popular tool during the conceptual design stage. While the designs produced by TO methods provide significant performance-to-mass ratio improvements, they require considerable computational resources when solving large-scale problems. An alternative for large-scale problems is to decompose the design domain into multiple scales that are coupled with homogenization. The problem can then be solved with hierarchical multiscale topology optimization (MSTO). The resulting optimal, homogenized macroscales are de-homogenized to obtain a high-fidelity, physically-realizable design. Even so MSTO methods are still computationally expensive due to the combined costs of solving nested optimization problems and performing de-homogenization. To address these issues, this paper presents an efficient de
Najmon, JoelTovar, Andres
Frontal crashes are the most common crash mode in the US vehicle fleet, and a large proportion of these crashes are “fender-benders” or low-speed collisions. This, among other considerations, led the Insurance Institute for Highway Safety (IIHS) to conduct a series of low-speed front and rear bumper impact tests. These crash tests have been performed on passenger vehicles manufactured by various manufacturers since 1970 and continuing through the 2009 model year. Test data and video for individual tests are available through IIHS’s online data portal, most extensively for model years 2007 to 2009. While IIHS’s test protocol varied over the years, these tests specified, in part, a full engagement impact of the tested vehicle into a rigid, bumper-shaped barrier covered with an energy absorber. Although IIHS reported the closing speed for each test, they did not report the separation speed or crash pulse duration. These values have been determined, in the current study, by analyzing the
Paradiso, MarcMcDowell, Eric
This SAE Standard sets forth accepted definitions and terminology of major components and parts peculiar to snowmobiles.
Snowmobile Technical Committee
This work is developed in the framework of an industrial R&D project, titled ARIA (Active Responsive Intelligent Aerodynamics), having the main goal to improve the efficiency of a vehicle by introducing active aerodynamics supported by innovative actuation systems. The work focuses on the development of a new aesthetic Active Grille Shutter (AGS), which, differently from the currently marketed vehicles, does not include the presence of a grille in front of it. In addition, an innovative actuation system, based on the adoption of Shape Memory Alloys (SMA) is being investigated for the new AGS, with the main goal to exploit the advantages arising in terms of increased efficiency coupled with a marked weigh reduction. The proposed analysis aims, at first, at evaluating the effects of different AGS configurations on the drag coefficient, Cx, of the vehicle and on the related benefits. To this purpose, simulations of the whole vehicle are carried out to estimate the Cx in different AGS
Perrone, DiegoRodinò, StefanoCurcio, ElioCastiglione, TeresaBova, SergioMaletta, CarmineBrandizzi, Marco
Recently, an aerodynamic theory for active grille shutters (AGS) of road vehicles has been developed that analytically describes the relationship among the flap position, cooling air mass flow, and drag. The experimentally validated theory is based on the assumption of a geometrically simple shutter which is arranged in a straight air duct and is flowed frontally, i.e., perpendicular to the flap plane. In the present work, this theory is extended and it is investigated how an inclined position affects the aerodynamic characteristic of an AGS. The theoretical results are then validated experimentally. Measurements on real vehicles with suitable AGS are used for this purpose. The results show good agreement between the theoretical predictions and experiment. The theoretical and experimental analyses allow conclusions to be drawn about how and under what conditions an inclined position affects the aerodynamic behavior of AGS.
Wolf, Thomas
Light weighting is an effective strategy in increasing energy efficiency in the automotive industry. In this paper, mass reduction with cost benefit was targeted in an exterior trim panel. Polypropylene copolymer (PPCP) compound was developed for a large exterior trim panel (1400 X 700mm) having an integrated grill mesh. The part had challenging requirements in terms of slow speed impact, structural durability, dimensional stability, aesthetics, thermal ageing resistance, cold impact resistance, scratch resistance and weathering resistance. By having ultra-high flow behavior, optimum tensile strength, modulus, impact strength and thermal properties, the PPCP compound met the requirements for a thin wall exterior trim panel with a thickness of 2.6mm. Structural durability of the design was validated by virtual engineering. Part design and material combinations with better tooling design iterations were analyzed by using mold flow analysis. Complete product performances were being
Govindaraj, KarthikVimalathithan, MurukesanYanamandra, BharadwajaD., Venkatesan
As new technology is added to vehicles and traffic congestion increases, there is a concern that drivers will be overloaded. As a result, there has been considerable interest in measuring driver workload. This can be achieved using many methods, with subjective assessments such as the NASA Task Loading Index (TLX) being most popular. Unfortunately, the TLX is unanchored, so there is no way to compare TLX values between studies, thus limiting the value of those evaluations. In response, a method was created to anchor overall workload ratings. To develop this method, 24 subjects rated the workload of clips of forward scenes collected while driving on rural, urban, and limited-access roads in relation to 2 looped anchor clips. Those clips corresponded to Level of Service (LOS) A and E (light and heavy traffic) and were assigned values of 2 and 6 respectively. Subjects said if they would perform any of 3 tasks—dialing a phone, manually tuning a radio, or entering a destination—while they
Green, Paul
Researches on pedestrian protection have become a very important theme in automotive industry. Design for vehicle front-bumper system has proven rather essential and been extensively used to improve the vehicle performance of pedestrian protection. However, there are some limitations in the design of vehicle front-bumper system to meet a multiple-pedestrian impact conditions at the same time. In order to improve the vehicle performance of lower extremity and pelvis protection for pedestrian, a new type of front bumper airbag was developed. Firstly, based on European New Car Assessment Programme (Euro-NCAP), the Flexible Pedestrian Legform Impactor (Flex-PLI) to vehicle and Upper Pedestrian Legform Impactor (U-PLI) to vehicle impact tests are carried out to evaluate the pedestrian protection performance of the initial structure. Secondly, the structural design of the bumper airbag is carried out, including the layout of the bumper airbag, the shape of the bumper airbag and the parameter
Zhu, HeWang, GuorongLv, XiaojiangHu, ShuaishuaiYang, HepingLiang, YunWang, Pengxiang
The Range Rover Evoque is a compact luxury SUV, first introduced by Land Rover in 2012. Almost 800,000 units of the first-generation vehicle were sold. This paper explores some of the challenges entailed in developing the next generation of this successful product, maintaining key design cues while at the same time improving its aerodynamic efficiency. A development approach is outlined that made use of both numerical simulation and full-scale moving ground wind tunnel testing. A drag coefficient of 0.32 was obtained for the best derivative by paying particular attention to: the integration of active grille shutters; the front bumper and tyre package; brake cooling; underfloor design; wake control strategy; and detail optimization. This approach delivered the most aerodynamic Range Rover at the time of its introduction. The impact of these design changes on the aerodynamic flow field and consequently drag is highlighted. An interaction between front wheel deflectors and different tyres
de Boer, MarcGaylard, Adrian P.Parmar, Bhavik
In this article, a methodology is presented to assess the influence of time-averaged deformations on a production car of the 2018 A-class due to wind load. Exemplary, the deformations of the front and rear bumper are investigated. The aerodynamic development of vehicles at Mercedes-Benz is divided into several phases. When comparing force coefficients, differences can be observed between these distinct hardware stages as well as when comparing steady-state simulations to wind tunnel measurements. In early phases when prototype vehicles are not yet available, so-called aero foam models are used. These are well-defined full-sized vehicle models as the outer skin is milled from Polyurethane. Important aerodynamic characteristics such as an engine compartment with a cooling module, deflecting axles with rotatable wheels, and underbody covers are represented. As attachment parts such as the front and the rear bumper are also milled from Polyurethane, they cannot deform under wind load
Renz, Philipp
In the present work, it is investigated how a flush arrangement to the outer skin affects the aerodynamic characteristic curve of active grille shutters (AGS). For this purpose, a recently developed theory, which analytically describes the aerodynamic behavior of AGS arranged in a straight flow channel, is extended accordingly, and the influence of an arrangement of AGS flush with the outer skin is first theoretically analyzed. The theoretical results are then validated experimentally. For this purpose, measurements of real vehicles with suitable AGS are used. The results show a good agreement of the theoretical predictions with the experiment. The theoretical and experimental analyses allow conclusions to be drawn as to how and under what conditions an arrangement flush with the outer skin affects the aerodynamic behavior of AGS.
Wolf, Thomas
This SAE Standard provides installation requirements, test procedures, design guidelines, and performance requirements for backup/reversing lamps.
Signaling and Marking Devices Stds Comm
Recently, the Flexible Pedestrian Legform Impactor (or Flex-PLI) - an advancement over the existing EEVC legform - was included in the Global Technical Regulation for Pedestrian Safety viz. GTR-9. The legform tool undergoes impact testing with vehicle at 40kmph in order to evaluate the frontal structure of vehicle for Pedestrian Safety. Being more biofidelic design over the old EEVC legform, Flex-PLI is more flexible and sensitive towards different vehicle designs, shapes and inner bumper structure. This flexibility and sensitiveness of its design also calls for examining the Manufactured FlexPLI for its efficacy under impact testing in terms of its Durability, Repeatability and Reproducibility. This study aims at validating the performance of the test device by building a platform for computing the variations in test results. In this study, three key aspects are identified to measure the performance of this device - Durability, Repeatability, and Reproducibility. Through extensive
Jain, SubhavLamba, RahulKumar, Manoj
Aesthetics contribute significantly to the customer’s buying decision of an automobile. This is traditionally achieved through painting. Sustainability and cost challenges have led automakers to look at substituting painting through molded-in color polymers in decorative bezels like pillar appliques. These appliques and bezels have a unique mix of material requirements that include color tone, gloss, stiffness, scratch resistance and weathering. Polycarbonates are an interesting class of polymers that has the potential to meet these challenging requirements. This paper reports the work done in evaluating a polycarbonate compound in piano black shade to meet the functional and aesthetic requirements. The results prove that the material can substitute painting thereby resulting in significant cost savings. This is a ready to mold material used in injection molding process. This modified polycarbonate material has been explored for thin wall appliques and bezels with thickness of 2.7 mm
Govindaraj, KarthikVimalathithan, MurukesanBalaji, K VSamir, Gandhihebbar, vinayak
This SAE Aerospace Information Report (AIR) covers the field of civilian, commercial and military airplanes and helicopters. This summary of tail bumper design approaches may be used by design personnel as a reference and guide for future airplanes and helicopters that require tail bumpers. Those described herein will consist of simple rub strips, structural loops with a wear surface for runway contact, retractable installations with replaceable shock absorbers and wear surfaces and complicated retractable tail landing gears with shock strut, wheels and tires. The information will be presented as a general description of the installation, its components and their functions.
A-5B Gears, Struts and Couplings Committee
This SAE Information Report establishes procedures and terminology for measuring, calculating, and referencing the percent vehicle overlap for a case vehicle in real-world or staged end plane collisions where the end plane of the case vehicle is engaged at one of the two bumper corners but not both. This SAE Information Report may be applied to rear or front plane impacts.
Crash Data Collection and Analysis Standards Committee
The kinematic response of vehicle occupants involved in tractor-to-passenger vehicle sideswipes was examined through a series of 13 crash tests. Each test vehicle and its occupants were instrumented with accelerometer arrays to measure and quantify the impact severity at various inter-vehicular angles and impact velocities. The passenger vehicle was occupied by a volunteer test subject in the driver and right-front passenger positions. The impact angle was varied between 3° and 11° to produce a sideswipe collision between the front bumper, steered wheel, and side components of the tractor and the side panels of the struck vehicle. The passenger vehicles were struck at different locations along their longitudinal axis at impact velocities between 3 mph and 11.5 mph. Accelerations were measured at the lumbar, cervicothoracic, and head regions of the driver and right-front passenger of the struck vehicle and the tractor driver. Approval from an Institutional Review Board (IRB) was
Bonugli, EnriqueGreenston, MathewScott, WilliamFolley, AustinWood, RawsonGwin, Lisa
Since bumper reinforcements are positioned at front/rear ends of vehicles, weight reduction of the bumper reinforcements enhances vehicle dynamic performance by reducing a yaw moment of inertia. CFRP (Carbon Fiber Reinforced Plastic) composites are attractive lightweight materials due to their excellent specific strength and rigidity. However, because of their relatively high cost, applications of CFRP materials to vehicle structural parts are limited. In this study we have developed a lightweight, structural part, which consists of a thin-walled Al (Aluminum) bumper reinforcement with a UD (Unidirectional)-CFRP sheet. The intention is to prevent an increased part cost by reducing the amount of Al and by minimizing the amount of CFRP. Compared to Al, UD-CFRP sheets have even higher tensile strength and modulus. When vehicles crash, bumper reinforcements may be subjected to bending force. If a UD-CFRP sheet is adhered on the tensile side of an Al bumper reinforcement, not only Al
Miura, MasayaIshii, MichiharuTakaoka, KanjiHoribe, YasumasaKitakata, ShintaroMikuni, Atsushi
Automotive Event Data Recorders (EDRs) are often utilized to determine or validate the severity of vehicle collisions. Several studies have been conducted to determine the accuracy of the longitudinal change in velocity (ΔV) reported by vehicle EDRs. However, little has been published regarding the measurement of EDRs that are capable of reporting lateral ΔVs in low-speed collisions. In this study, two 2007 Toyota Camrys with 04EDR ECU Generation modules (GEN2) were each subjected to several vehicle-to-vehicle lateral impacts. The impact angles ranged from approximately 45 to 135 degrees and the stationary target vehicles were impacted at the frontal, central, and rear aspects of both the driver and passenger sides. The impact locations on the bullet vehicles were the front and rear bumpers and the impact speeds ranged from approximately 7.9 to 16.1 km/h. Instrumentation was mounted at the approximate center of gravity (CG) of the target vehicles, as well as on the front reinforcement
Swinford, ScottJones, BrianBrink, JustinFurbish, ChristopherWelcher, JudsonAnderson, Robert
In frontal collision of vehicles, the front bumper system is the first structural member that receives the energy of collision. In low speed impacts, the bumper beam and the crush cans that support the bumper beam are designed to protect the engine and the radiator from being damaged, while at high speed impacts, they are required to transfer the energy of impact as uniformly as possible to the front rails that contributes to the occupant protection. The bumper beam material today is mostly steels and aluminum alloys, but carbon fiber composites have the potential to reduce the bumper weight significantly. In this study, crash performance of bumper beams made of a boron steel, aluminum alloy 5182 and a carbon fiber composite with steel crush cans is examined for their maximum deflection, load transfer to crush cans, total energy absorption and failure modes using finite element analysis. All three beams have the same design features, but their thickness is varied to maintain the same
Kudav, DeeptejMallick, Pankaj K.
Aerodynamic technologies for light-duty vehicles were evaluated through full-scale testing in a large low-blockage closed-circuit wind tunnel equipped with a rolling road, wheel rollers, boundary-layer suction and a system to generate road-representative turbulent flow. This work was part of a multi-year, multi-vehicle study commissioned by Transport Canada and Environment and Climate Change Canada, and carried out in cooperation with the US EPA, to support the evaluation of light-duty-vehicle greenhouse-gas-emission regulations. A 2016 paper reported drag-reduction measurements for technologies such as active grille shutters, production and custom underbody treatments, air dams, ride height control and combinations of these. This paper describes an extension to that work and addresses vehicle aerodynamics in three ways. First, whole vehicle body-shaping changes were evaluated by adding older or newer generation models, representing distinct body style redesigns, of select vehicles of
de Souza, FenellaRaeesi, ArashBelzile, MarcCaffrey, CherylSchmitt, Andreas
This SAE Aerospace Information Report (AIR) covers the field of civilian, commercial and military airplanes and helicopters. This summary of tail bumper design approaches may be used by design personnel as a reference and guide for future airplanes and helicopters that require tail bumpers. Those described herein will consist of simple rub strips, structural loops with a wear surface for runway contact, retractable installations with replaceable shock absorbers and wear surfaces and complicated retractable tail landing gears with shock strut, wheels and tires. The information will be presented as a general description of the installation, its components and their functions.
A-5B Gears, Struts and Couplings Committee
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