Browse Topic: Safety testing and procedures

Items (5,372)
Recent studies have investigated head injury metrics, including mild traumatic brain injury (mTBI), or concussion risks, in low- to moderate-speed rear-end collisions, with linear and angular head accelerations contributing to the risk of developing a concussion. The present study analyzes head acceleration values in rear-end collisions at an impact severity of 5–30 km/h delta-V. Biomechanical data was obtained from HIII 50th percentile male anthropomorphic test devices (ATDs) seated in the target subject vehicles and utilizing safety restraints and head rests. Concussion risks were calculated from resultant linear and angular head accelerations recorded in the ATDs, and a linear regression model was used to determine what, if any, relationship existed between these head injury metrics and impact severity. The results indicate that there is a significant and positive relationship between head acceleration metrics and impact severity, particularly in the sagittal plane, with F-values
Garcia, BeatrizEmanet, Hatice SeydaHoffman, Austin
Image dehazing techniques can play a vital role in object detection, surveillance, and accident prevention, especially in scenarios where visibility is compromised because of light scattering by atmospheric particles. To obtain a high-quality image or as an initial step in processing, it’s crucial to restore the scene’s information from a single image, given that this is an ill-posed inverse problem. The present approach utilized an unsupervised learning approach to predict the transmission map from a hazy image and used YOLOv8n to detect the car from a clear recovered image. The dehazing model utilized a lightweight parallel channel architecture to extract features from the input image and estimate the transmission map. The clear image is recovered using an atmospheric scattering model and given to the YOLOv8n for car detection. By incorporating dark channel prior loss during training, the model eliminates the need for a paired dataset. The proposed dehazing model with fewer
Dave, ChintanPatel, HetalKumar, Ahlad
This study introduces an innovative intelligent tire system capable of estimating the risk of total hydroplaning based on water pressure measurements within the tread grooves. Dynamic hydroplaning represents an important safety concern influenced by water depth, tread design, and vehicle longitudinal speed. Existing intelligent tire systems primarily assess hydroplaning risk using the water wedge effect, which occurs predominantly in deep water conditions. However, in shallow water, which is far more prevalent in real-world scenarios, the water wedge effect is absent at higher longitudinal speeds, which could make existing systems unable to reliably assess the total hydroplaning risk. Groove flow represents a key factor in hydroplaning dynamics, and it is governed by two mechanisms: water interception rate and water wedge pressure. In both the shallow water and deep water cases, the groove water flow will increase as a result of increasing the longitudinal speed of the vehicle for a
Vilsan, AlexandruSandu, CorinaAnghelache, GabrielWarfford, Jeffrey
Researchers at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) previously conducted a full-scale crash test of a Fokker F28 MK1000 aircraft to study occupant injury risks. The goal of the current study was to investigate the injury predictions of the Global Human Body Models Consortium (GHBMC) and Total Human Model for Safety (THUMS) occupant models in the tested aircraft crash condition and explore possible utilization of both human body models (HBMs) in this context. Eight crash conditions were simulated utilizing each of the models. The HBMs were positioned in two postures, a neutral upright posture with hands resting on the legs and feet contacting the floor and a braced posture with head and hand contact with the forward seat back. Head and neck injury metrics and lumbar vertebra axial force were calculated and compared for all simulations. Both HBMs reported similar kinematic responses in the simulated impact conditions. However, the GHBMC
Jones, NathanielPutnam, JacobUntaroiu, Costin Daniel
Current voluntary standards for wheelchair crashworthiness only test under frontal and rear impact conditions. To help provide an equitable level of safety for occupants seated in wheelchairs under side impact, we developed a sled test procedure simulating nearside impact loading using a fixed staggered loading wall. Publicly available side impact crash data from vehicles that could be modified for wheelchair use were analyzed to specify a relevant crash pulse. Finite element modeling was used to approximate the side impact loading of a wheelchair during an FMVSS No. 214 due to vehicle intrusion. Validation sled tests were conducted using commercial manual and power wheelchairs and a surrogate wheelchair base fixture. Test procedures include methods to position the wheelchair to provide consistent loading for wheelchairs of different dimensions. The fixture and procedures can be used to evaluate the integrity of wheelchairs under side impact loading conditions.
Boyle, KyleHu, JingwenManary, MiriamOrton, Nichole R.Klinich, Kathleen D.
Composite materials are increasingly utilized in industries such as automotive and aerospace due to their lightweight nature and high strength-to-weight ratio. Understanding how strain rate affects the mechanical and crashworthiness properties of CFRP composites is essential for accurate impact simulations and improved safety performance. This study examines the strain rate sensitivity of CFRP composites through mechanical testing and finite element analysis (FEA). Experimental results confirm that compressive strength increases by 100%–200% under dynamic loading, while stiffness decreases by up to 22% at a strain rate of 50 s−1, consistent with trends observed in previous studies. A sled test simulation using LS-Dyna demonstrated that the CFRP crash box sustained an average strain rate of 46.5 s−1, aligning with realistic impact conditions. Incorporating strain rate–dependent material properties into the FEA model significantly improved correlation with experimental crashworthiness
Badri, HesamJayasree, Nithin AmirthLoukodimou, VasilikiOmairey, SadikBradbury, AidanLidgett, MarkPage, ChrisKazilas, Mihalis
Electric vehicles (EVs) differ from internal combustion engine (ICE) vehicles in that they lack a conventional engine and feature an electric drive unit, leading to distinct dynamic behaviours in the powertrain. Additionally, the arrangement of auxiliary components in EVs often differs from that in traditional ICE vehicles, which can sometimes significantly impact safety ratings. This paper examines a case study of a critical failure during a crash test, where displacement of an engine mount arm caused substantial structural intrusion and reduced the vehicle’s safety rating. To address this issue and enhance crashworthiness, a “crash plate” was designed and integrated into the mount system. This solution effectively constrained the mount arm’s movement during impact, preventing the intrusion observed in previous tests. The paper provides a detailed analysis of the crash plate’s dimensions and its relationship to the engine mount, demonstrating its potential for broader application in
Hazra, SandipKhan, ArkadipMohare, Gourishkumar
Performing highly representative tests of aircraft equipment is a critical feature for gaining utmost confidence on their ability to perform flawlessly in flight under the entire spectrum of operating conditions. This can also contribute to accelerate the certification process of a new equipment. A research project (E-LISA) was performed in recent years, as part of the European funded Clean Sky 2 framework, with the objective of building an innovative facility for testing an electrically actuated landing gear and brake for a small air transport. The project eventually led to the development and construction of an Iron Bird able to reproduce in a realistic and comprehensive way a full variety of landing test cases consistent with certification specifications and landing histories available in the repository of the airframer. The Iron Bird that was eventually developed is a multi-functional intelligent and easy reconfigurable facility integrating hardware and software allowing to perform
De Martin, AndreaBertolino, AntonioJacazio, Giovanni
Airworthiness certification of aircraft requires an Airworthiness Security Process (AWSP) to ensure safe operation under potential unauthorized interactions, particularly in the context of growing cyber threats. Regulatory authorities mandate the consideration of Intentional Unauthorized Electronic Interactions (IUEI) in the development of aircraft, airborne software, and equipment. As the industry increasingly adopts Model-Based Systems Engineering (MBSE) to accelerate development, we aim to enhance this effort by focusing on security scope definitions – a critical step within the AWSP for security risk assessment that establishes the boundaries and extent of security measures. However, our findings indicate that, despite the increasing use of model-based tools in development, these security scope definitions often remain either document-based or, when modeled, are presented at overly abstract levels, both of which limit their utility. Furthermore, we found that these definitions
Hechelmann, AdrianMannchen, Thomas
This document describes a method for measuring transient force histories generated by the impact of a soft or frangible projectile on a thin slicer oriented in a plane parallel to the direction of the projectile motion. The slicer is intended to be representative of a typical turbofan engine fan blade. The document describes the hardware and instrumentation required as well as the processing and data reduction required to compute force. In this test, a projectile impacts a relatively thin, flat, blade-like device with a sharp leading edge (the “slicer”). The direction of motion of the projectile is parallel to the plane of the slicer. The test is designed to minimize lateral motion in the projectile as a result of the impact. The intended impact velocity range for this test is between approximately 50 and 300 m/sec. The slicer has a width greater than the largest diameter of the projectile and is supported on a fixture instrumented to measure force. The projectile material is expected
G-28 Simulants for Impact and Ingestion Testing Committee
This aerospace standard provides guidance for use in demonstrating compliance with powerplant fire protection requirements by fire test.
A-22 Fire Protection and Flammability Testing Committee
The New Car Assessment Program (e.g., US NCAP and EuroNCAP) frontal crash tests are an essential part of vehicle safety evaluations, which are mandatory for the certification of civil means of transport prior to normal road exploitation. The presented research is focused on the behavior of a tubular low-entry bus frame during a frontal impact test at speeds of 32 and 56 km/h, perpendicular to a rigid wall surface. The deformation zones in the bus front and roof parts were estimated using Ansys LS-DYNA and considered such factors as the additional mass (1630 kg) of electric batteries following the replacement of a diesel engine with an electric one. This caused stabilization of the electric bus body along the transverse axis, with deviations decreased by 19.9%. Speed drop from 56 to 32 km/h showed a reduction of the front window sill deformations from 172 to 132 mm, and provided a twofold margin (159.4 m/s2) according to the 30g ThAC criterion of R80. This leads to the conclusion about
Holenko, KostyantynDykha, AleksandrKoda, EugeniuszKernytskyy, IvanRoyko, YuriyHorbay, OrestBerezovetska, OksanaRys, VasylHumeniuk, RuslanBerezovetskyi, SerhiiChalecki, Marek
Headliners are one of the largest components inside an automobile, stretching from the front windshield to the rear windshield. Besides its aesthetic purpose, it contributes to multiple other purposes like housing different components, helps in NVH, defines the interior roominess, and plays a crucial role in defining the deployment of curtain airbag. The headliner also plays a role in meeting regulatory requirements like upward visibility and headroom requirements of the occupants. During the deployment of curtain airbag, it is important that the headliner-pillar interface aids in the easy opening of airbag, with the least hindrance. This is defined by multiple factors like the location of headliner-pillar interface, its distance from the airbag ramp bracket, the position of the inflator, the mountings of the headliner and pillar trims, to name a few. Also, during the deployment of the airbag, it is important that parts such as grabhandle, speaker grilles, etc which are fitted on the
Sabesan, Arvind KochiD., AnanthaKakani, Phani Kumar
This paper proposes a structured safety framework tailored for the concept phase of Level 2 and Level 3 automated vehicles, addressing the unique challenges posed by these advanced systems. The framework integrates key principles from ISO 26262 and ISO 21448 to create a safety approach that spans hardware reliability, functional safety, and system performance. Central to the framework is a broad analysis that combines methodologies from System-Theoretic Process Analysis (STPA) and Hazard Analysis and Risk Assessment (HARA). This dual approach enables the identification of potential risks arising from both hardware failures and the intended functionalities of the system. The framework further details a combined specification and design process that aligns the strengths of each standard, ensuring robust sensor architectures and reliable decision-making processes. A case study on Adaptive Cruise Control with Lane Keeping is presented to demonstrate the practical implementation of the
Sari, Ayse AysuSoleimani, Morteza
The development of autonomous driving technology will liberate the space in the car and bring more possibilities of comfortable and diverse sitting postures to passengers, but the collision safety problem cannot be ignored. The aim of this study is to investigate the changes of injury pattern and loading mechanism of occupants under various reclined postures. A highly rotatable rigid seat and an integrated three-point seat belt were used, with a 23g, 50kph input pulse. Firstly, the sled test and simulation using THOR-AV in a reclined posture were conducted, and the sled model was verified effective. Based on the sled model, the latest human body model, THUMS v7, was used for collision simulation. By changing the angle of seatback and seat pan, 5 seat configurations were designed. Through the calculation of the volunteers' pose regression function, the initial position of THUMS body parts in different seat configurations was determined. The responses of human body parts were output
Yang, XiaotingWang, QiangLiu, YuFei, JingWang, PeifengLi, ZhenBai, Zhonghao
The integrated vehicle crash safety design provides longer pre-crash preparation time and design space for the in-crash occupant protection. However, the occupant’s out-of-position displacement caused by vehicle’s pre-crash emergency braking also poses challenges to the conventional restraint system. Despite the long-term promotion of integrated restraint patterns by the vehicle manufacturers, safety regulations and assessment protocols still basically focus on traditional standard crash scenarios. More integrated crash safety test scenarios and testing methods need to be developed. In this study, a sled test scenario representing a moderate rear-end collision in subsequence of emergency braking was designed and conducted. The bio-fidelity of the BioRID II ATD during the emergency braking phase is preliminarily discussed and validated through comparison with a volunteer test. The final forward out-of-position displacement of the BioRID II ATD falls within the range of volunteer
Fei, JingWang, PeifengQiu, HangLiu, YuShen, JiajieCheng, James ChihZhou, QingTan, Puyuan
In the pre-crash emergency braking scenario, the occupant inside the vehicle will move forward due to inertia, deviating from the standard upright seating position for which conventional restraint systems are designed. Previous studies have mainly focused on the influence of out-of-position (OOP) displacement on occupant injuries in frontal collisions, and provided solutions such as active pretensioning seatbelts (APS). But little attention has been paid to the influence of OOP on whiplash injury during a subsequent rear-end collision. To investigate the forward OOP impact on whiplash injuries and the effectiveness of APS in this accident scenario, a vehicle interior model with an active human body model (AHBM) was setup in the MADYMO simulation platform. Different braking strengths (0.8g and 1.1g), APS triggering times (from 0.2s before to 0.2s after the braking initiation) and pretensioning forces (from 100N to 600N) were input to the simulation matrix. The occupant’s forward OOP
Fei, JingQiu, HangWang, PeifengLiu, YuCheng, James ChihZhou, QingTan, Puyuan
The National Highway Safety Administration (NHTSA) recently published an Advanced Notice of Proposed Rulemaking (ANPRM) to evaluate seat performance in rear impacts [1]. The ANPRM was issued partially in response to two petitions requesting an increase in seatback strength requirements and high-speed testing with various size Anthropometric Test Devices (ATDs). To better understand the effect of these requests, this study evaluates ATD responses with two high-speed rear sled conditions, three occupant sizes and various seat designs. Seat designs varied from modern conventional seats with yielding properties to stronger and stiffer seats represented by seat integrated restraint (SIR) designs, and rigidized SIR seats. Twenty-four rear sled tests were analyzed. The tests were matched by crash severity, seat designs (strength), ATD sizes and initial postures (nominal/in-position, leaned forward and leaned outboard). The test data and videos were reviewed to identify time coinciding with
Parenteau, ChantalBurnett, Roger
The National Highway Traffic Safety Administration (NHTSA) published an Advance Notice of Proposed Rulemaking (ANPRM) to update the Federal Motor Vehicle Safety Standard (FMVSS) 207. Part of the ANPRM is to assess the merit of conducting quasi static body block seat pull tests and conducting FMVSS 301 rear crash tests at 80 km/h or higher with a 95th percentile ATD lap-shoulder belted in the front seats and limiting seatback deflection to 15 to 25 degrees. Prior to updating regulations, it is important to understand the seating design history and implications. This study was conducted to provide a historical background on seat design and performance using literature and test data. One objective was to first define the terminology used to describe occupant kinematics in rear crashes. Secondly, seat design evolution is then discussed. Third, test methods and test results were summarized, and fourth, the field performance are synopsized and discussed with respect to 2nd row occupant
Parenteau, ChantalBurnett, RogerDavidson, Russell
Research on modeling head injury metrics and head acceleration waveforms from real-world collisions has been limited compared to vehicle crash pulses. Prior studies have used rectangular, triangular, polynomial, half-sine, and haversine pulse functions to model vehicle crash pulses and have employed more complex approximations for head injury metrics. This study aimed to develop a method to predict 15 ms Head Injury Criterion (HIC15) in frontal passenger vehicle impacts using these simple pulse functions, where only occupant peak head acceleration and head impact duration are known. Vehicle crash tests from the New Car Assessment Program (NCAP) were selected for frontal impacts that included driver occupants. Head acceleration and shoulder belt load channels of Hybrid III 50th percentile male anthropomorphic test devices were collected and separated for training a set of ratios and testing their performance. Rectangular, triangular, quadratic, half-sine, and haversine pulse functions
Westrom, ClydeTanczos, RachelAdanty, KevinShimada, Sean
Peak upper and lower neck load data from rear impact crash testing were reviewed, aggregated, and analyzed from over 1,800 tests of existing peer-reviewed literature and research as well as available testing conducted by the Insurance Institute for Highway Safety (IIHS) and the National Highway Traffic Safety Administration (NHTSA). Both human volunteers and anthropomorphic test devices (ATDs) were subjects of the reviewed studies and testing. Peak upper and lower neck axial forces (compression and tension), sagittal shear forces, and sagittal moments (flexion and extension) from available crash testing were reported and analyzed as functions of measured change in velocity (delta-V) ranging from approximately 3 to 60 km/h (1.9 to 37 mph). This load data was then further analyzed for possible trends amongst various testing conditions, such as seat type, ATD used, and subject seating position within the vehicle chassis and seat to develop a simple linear model. The linear regressions
Kazmierczak, AlexUmale, SagarVisalli, AlyssaWebb, EllaKashdan, AryehRandles, BryanWelcher, Judson
A total of 148 tests were conducted to evaluate the Forward Collision Warning (FCW) and Automatic Emergency Braking (AEB) systems in five different Tesla Model 3 vehicles between model years 2018 and 2020 across four calendar years. These tests involved stationary vehicle targets, including a foam Stationary Vehicle Target (SVT), a Deformable Stationary Vehicle Target (DSVT), a live vehicle with brake lights, and a SoftCar360 designed for high-speed impact tests. The evaluations were conducted at speeds of 35, 50, 60, 65, 70, 75, and 80 miles per hour (mph) during both daytime and nighttime conditions and utilized early and medium FCW settings. These settings, part of Tesla's Collision Avoidance AssistTM, modify object detection alerts and the timing of visual and auditory warnings issued to drivers. The 2018 to 2020 vehicles initially utilized cameras, radar and ultrasonic sensors (USS) for object detection. Tesla updated their Autoilot software and detection algorithms to a vision
Harrington, ShawnNagarajan, Sundar Raman
Camera matching photogrammetry is widely used in the field of accident reconstruction for mapping accident scenes, modeling vehicle damage from post collision photographs, analyzing sight lines, and video tracking. A critical aspect of camera matching photogrammetry is determining the focal length and Field of View (FOV) of the photograph being analyzed. The intent of this research is to analyze the accuracy of the metadata reported focal length and FOV. The FOV from photographs captured by over 20 different cameras of various makes, models, sensor sizes, and focal lengths will be measured using a controlled and repeatable testing methodology. The difference in measured FOV versus reported FOV will be presented and analyzed. This research will provide analysts with a dataset showing the possible error in metadata reported FOV. Analysts should consider the metadata reported FOV as a starting point for photogrammetric analysis and understand that the FOV calculated from the image
Smith, Connor A.Erickson, MichaelHashemian, Alireza
Abstract This paper introduces a method to solve the instantaneous speed and acceleration of a vehicle from one or more sources of video evidence by using optimization to determine the best fit speed profile that tracks the measured path of a vehicle through a scene. Mathematical optimization is the process of seeking the variables that drive an objective function to some optimal value, usually a minimum, subject to constraints on the variables. In the video analysis problem, the analyst is seeking a speed profile that tracks measured vehicle positions over time. Measured positions and observations in the video constrain the vehicle’s motion and can be used to determine the vehicle’s instantaneous speed and acceleration. The variables are the vehicle’s initial speed and an unknown number of periods of approximately constant acceleration. Optimization can be used to determine the speed profile that minimizes the total error between the vehicle’s calculated distance traveled at each
Snyder, SeanCallahan, MichaelWilhelm, ChristopherJohnk, ChrisLowi, AlvinBretting, Gerald
As the high-quality development of the new energy vehicle (NEV) and traction battery industries, the safety of traction batteries has become a global focus. Typically mounted at the bottom of NEVs, traction battery systems are particularly vulnerable to mechanical damage caused by bottom impacts, posing serious safety risks. This study investigates the damage sustained by NEV traction battery systems during bottom impact collisions, using computer tomography analysis to detail the damage mechanisms. The findings provide valuable data to enhance the safety and protective performance of traction batteries under such scenarios.
Yan, PengfeiWang, FangMa, TianyiHan, CeHe, Gaiyun
Emerging automotive technologies like advanced driver assistance systems (ADAS) and automated driving systems (ADS) hold promise for improving safety for the traveling public; however, effective verification and validation (V&V) of these systems has proven to be challenging. Traditional testing methodologies may serve in limited cases for systems exhibiting low levels of automation, but recent studies show that these systems that have been brought to market perform poorly in practice. Further, these traditional methods do not serve for testing systems with high levels of automation where a human driver simply serves as a fallback ready user or is out of the loop altogether. New V&V methods are required to assess whether these systems can perform their intended functions in their intended operating environments, and to assess whether they can do so safely across the expansive and variable operating space. This paper presents an overview of ADAS and ADS challenges and novel approaches to
Thorn, EricKnisley, VeronicaAuchter, Joseph
As Automatic Emergency Braking (AEB) systems become standard equipment in more light duty vehicles, the ability to evaluate these systems efficiently is becoming critical to regulatory agencies and manufacturers. A key driver of the practicality of evaluating these systems’ performance is the potential collision between the subject vehicle and test target. AEB performance can depend on vehicle-to-vehicle closing speeds, crash scenarios, and nuanced differences between various situational and environmental factors. Consequently, high speed impacts that may occur while evaluating the performance of an AEB system, as a result of partial or incomplete mitigation by an AEB activation, can cause significant damage to both the test vehicle and equipment, which may be impractical. For tests in which impact with the test target is not acceptable, or as a means of increasing test count, an alternative test termination methodology may be used. One such method constitutes the application of a late
Kuykendal, MichelleEaster, CaseyKoszegi, GiacomoAlexander, RossParadiso, MarcScally, Sean
Two wheelers motorcycles are used for many purposes e.g. commuting from one place to another, long highway rides, racing and off-roading. Motorcycles which are used in off-road conditions require higher suspension strokes to absorb large oscillations due to terrain conditions. These motorcycles undergo jumps of varying heights and different vehicle orientations. In some of the dynamic situations front wheel may land on the ground before the rear and in other cases it may be vice versa. To make sure that the vehicle is durable enough to withstand loads in such operating conditions, vehicle drop test was developed in test lab where vehicle is dropped from predefined heights in both front & rear wheel landing conditions. Same test case is simulated in multibody dynamics to capture loads at important connections of the frame. This paper presents the correlation exercise carried out to validate MBD model and simulation process with test data captured during lab test. Accelerations at
Jain, Arvind KumarNirala, Deepak
India has one of the highest accident rates in the world. Quite a few accidents have been attributed to poor driver visibility. Driver visibility is an important factor that can help mitigate the risk of accidents. The optimal visibility of in-vehicle controls is also essential for improving driver experience. Optimized driver visibility improves driving comfort and gives confidence to the driver, ensuring the safety of drivers and subsequently that of pedestrians. Driver visibility is an important consideration for vehicle occupant packaging and SAE has defined various standards and regulations for the same. These guidelines are defined considering American anthropometry, helping OEMs create global vehicles with uniform checkpoints. However, due to anthropometric differences, a need was felt to capture and analyze Indian-specific eyellipse and eye points. To measure the eye point of the user in a controlled environment, the interiors of a passenger vehicle were simulated using a
P H, SalmanKalra, PreritaRawat, AshishSharma, DeepakSingh, Ashwinder
The rapid growth of electric vehicles (EVs) has led to a significant increase in vehicle mass due to the integration of large and heavy battery systems. This increase in mass has raised concerns about collision energy and the associated risks, particularly in high-speed impacts. As a consequence, crashworthiness evaluations, especially front-impact regulations, have become increasingly stringent. Crash speed between the vehicle and the Mobile Progressive Deformable Barrier (MPDB) is increasing, reflecting the growing emphasis on safety in the automotive industry. Moreover, a new frontal pole crash scenario is under consideration for future regulatory standards, highlighting the continuous evolution of crash testing protocols. To ensure occupant protection and battery safety, manufacturers have traditionally used Hot Blow Forming technology for producing closed-loop dash lower cross member components. However, this process is both costly and energy-intensive, necessitating more
Lee, JongminKim, DonghyunJang, MinhoKim, GeunhoSeongho, YooKim, Kyu-Rae
In recent years, energy scarcity and environmental pollution have intensified globally, prompting increased research and development in new energy vehicles as countries prioritize environmental protection and energy conservation. Compared to fuel-powered vehicles, new energy vehicles have relatively larger battery volumes and weights, which can increase damage and the risk of fires and explosions in collisions. To analyze and optimize the safety performance of a specific vehicle model's battery pack, we constructed a finite element model using existing software and performed pre-processing, simulation, and analysis of modal, random vibration, and extrusion characteristics. This revealed specific damage scenarios and enabled reliability analysis under working conditions. To enhance safety and reduce mass, we parametrically modeled power pack components and optimized parameters via multi-objective genetic algorithms under three road conditions. Results indicate reduced mass and improved
Wang, Zhi
In new energy vehicles, aluminum alloy has gained prominence for its ability to achieve superior lightweight properties. During the automotive design phase, accurately predicting and simulating structural performance can effectively reduce costs and enhance efficiency. Nevertheless, the acquisition of accurate material parameters for precise predictive simulations presents a substantial challenge. The Johnson-Cook model is widely utilized in the automotive industry for impact and molding applications due to its simplicity and effectiveness. However, variations in material composition, processing techniques, and manufacturing methods of aluminum alloy can lead to differences in material properties. Additionally, components are constantly subjected to complex stress states during actual service. Conventional parameter calibration methods primarily rely on quasi-static and dynamic tensile tests, offering limited scope in addressing compression scenarios. This paper proposes an inversion
Kong, DeyuGao, Yunkai
This study outlines a camera-based perspective transformation method for measuring driver direct visibility, which produces 360-degree view maps of the nearest visible ground points. This method is ideal for field data collection due to its portability and minimal space requirements. Compared with ground truth assessments using a physical grid, this method was found to have a high level of accuracy, with all points in the vehicle front varying less than 0.30 m and varying less than 0.6 m for the A- and B-pillars. Points out of the rear window varied up to 2.4 m and were highly sensitive to differences in the chosen pixel due to their greater distance from the camera. Repeatability through trials of multiple measurements per vehicle and reproducibility through measures from multiple data collectors produced highly similar results, with the greatest variations ranging from 0.19 to 1.38 m. Additionally, three different camera lenses were evaluated, resulting in comparable results within
Mueller, BeckyBragg, HadenBird, Teddy
In automotive engineering, seam welds are frequently used to join or connect various parts of structures, frames, cradles, chassis, suspension components, and body. These welds usually form the weaker material link for durability and impact loads, which are measured by lab-controlled durability and crash tests, as well as real-world vehicle longevity. Consequently, designing robust welded components while optimizing for material performance is often prioritized as engineering challenge. The position, dimensions, material, manufacturing variation, and defects all affect the weld quality, stiffness, durability, impact, and crash performance. In this paper, the authors present best practices based on studies over many years, a rapid approach for optimizing welds, especially seam welds, by adopting Design For Six Sigma (DFSS) IDDOV (Identify, Define, Develop, Optimization, and Verification) discrete optimization approach. We will present the case testimony to show the approach throughout
Qin, WenxinLi, FanPohl, Kevin J.Pentapati, Venkat
This paper presents a conceptual study on how to perform an 8-step software FMEA by adding a signal analysis step into the 7-step FMEA of AIAG-VDA1st edition. In 8-step software FMEA, structural analysis, functional analysis, and the newly added signal analysis steps correspond to software architecting. Thus, the 8-step software FMEA has the effect of integrating software architecting and FMEA, and this study defines it as integrated software FMEA. In the structure tree, the functionality-assigned elements are designed to produce their variables through signal analysis, and by utilizing this variable information, it is newly proposed that software FMEA can be linked and extended to dependent failure analysis and fault tree analysis. In addition, the optimization step uses the variable information to link failure mitigation and prevention measures to verification and validation tests with traceability, which is helpful to verify its results. Since the 7-step FMEA of AIAG-VDA1st edition
Han, PoongGyoo
Testing was conducted in daytime and nighttime conditions to evaluate the performance of the Automatic Emergency Braking and Forward Collision Warning systems present on both a 2020 and 2022 Kia Telluride. The 2022 Kia Telluride was tested during the day at speeds between 35 and 70 miles per hour, while the 2020 Kia Telluride was tested both during the day and at night at speeds between 35 and 60 miles per hour (mph). The daytime testing of both the 2020 and 2022 Kia Telluride utilized a foam stationary vehicle target. The nighttime testing of the 2020 Kia Telluride utilized a live 2006 Chevrolet Tahoe as the target with the brake lights on. Testing measured the Time to Collision (TTC) values of the visual/audible component of the Forward Collision Warning (FCW) that was presented to the driver. Further, testing also quantified the timing and magnitude of the two-phase response of the Automatic Emergency Braking (AEB) system. The results of both sets of testing add higher speed FCW and
Harrington, ShawnPatrick-Moline, PeytonNagarajan, Sundar Raman
Headlight glare remains a persistent problem to the U.S. driving public. Over the past 30 years, vehicle forward lighting and signaling systems have evolved dramatically in terms of styling and lighting technologies used. Importantly, vehicles driven in the U.S. have increased in size during this time as the proportion of pickup trucks and sport-utility vehicles (SUVs) has increased relative to passenger sedans and other lower-height vehicles. Accordingly, estimates of typical driver eye height and the height of lighting and signaling equipment on vehicles from one or two decades ago are unlikely to represent the characteristics of current vehicles in the U.S. automotive market. In the present study we surveyed the most popular vehicles sold in the U.S. and carried out evaluations of the heights of lighting and signaling systems, as well as typical driver eye heights based on male and female drivers. These data may be of use to those interested in understanding how exposure to vehicle
Bullough, John D.
Pelvic pusher energy absorption pad in a vehicle saves the occupant from pelvic injuries in the event of a crash, especially side or pole crash. This pelvic pusher pad plays a crucial role in absorbing the impact energy from the body side and minimizing the impact to the occupant. Positioning of pelvic pusher pad with respect to occupant manikin position and torso angle, stiffening criteria for the energy absorption pad, maximum force and energy absorption target setting methodology and evaluation methods through CAE and part level physical validations are all discussed in detail. Pelvic pusher pad are of various types such as EPP moulded, blow moulded or injection moulded and the criteria differ for each type. For EPP moulded type, based on the EPP grade, S-S Graph gets converted to F-S Graph and validated accordingly. F-S Graph for a test vehicle is generated through sled test where the sled is made to impact the pelvis of ES2 Dummy at a constant velocity and the F-S Graph is
S M, Rahuld, AnanthaKakani, Phani KumarMalliboina, Mahendra
Real-world data show that abdominal loading due to a poor pelvis-belt restraint interaction is one of the primary causes of injury in belted rear-seat occupants, highlighting the importance of being able to assess it in crash tests. This study analyzes the phenomenon of submarining using video, time histories, and statistical analysis of data from a Hybrid III 5th female dummy seated in the rear seat of passenger vehicles in moderate overlap frontal crash tests. This study also proposes different metrics that can be used for detecting submarining in full-scale crash tests. The results show that apart from the high-speed videos, when comparing time-series graphs of various metrics, using a combination of iliac and lap belt loads was the most reliable method for detecting submarining. Five metrics from the dynamic sensors (the maximum iliac moment, maximum iliac force drop in 1 ms, time for 80% drop from peak iliac force, maximum pelvis rotation, and lumbar shear force) were all
Jagtap, Sushant RJermakian, Jessica SEdwards, Marcy A
With the advancement of intelligent transportation and smart logistics systems, tractor semi-trailers have gradually become one of the primary modes of transport due to their substantial cargo capacity. However, the growing number of tractor semi-trailers has raised significant traffic safety concerns. Due to their significant spring mass and strong body strength, accidents involving tractor semitrailers often result in severe consequences. Active collision avoidance control strategies provide assurance for vehicle safety. However, existing research predominantly focuses on passenger cars and small commercial vehicles. Research specifically addressing tractor semi-trailers, which have longer bodies and more complex dynamic characteristics, is relatively sparse. Therefore, this paper proposes a collision risk assessment-based longitudinal collision avoidance control strategy for tractor semi-trailers with slip ratio control. Firstly, the paper introduces the braking characteristics and
Yan, YangZheng, HongyuZhang, Yuzhou
Reproducing driving scenarios involving near-collisions and collisions in a simulator can be useful in the development and testing of autonomous vehicles, as it provides a safe environment to explore detailed vehicular behavior during these critical events. CARLA, an open-source driving simulator, has been widely used for reproducing driving scenarios. CARLA allows for both manual control and traffic manager control (the module that controls vehicles in autopilot manner in the simulation). However, current versions of CARLA are limited to setting the start and destination points for vehicles that are controlled by traffic manager, and are unable to replay precise waypoint paths that are collected from real-world collision and near-collision scenarios, due to the fact that the collision-free pathfinding modules are built into the system. This paper presents an extension to CARLA’s source code, enabling the replay of exact vehicle trajectories, irrespective of safety implications
Ai, YanAdhikari, BikramPark, Chung-KyuKan, Cing-DaoWijesekera, Duminda
Off-road vehicles are required to traverse a variety of pavement environments, including asphalt roads, dirt roads, sandy terrains, snowy landscapes, rocky paths, brick roads, and gravel roads, over extended periods while maintaining stable motion. Consequently, the precise identification of pavement types, road unevenness, and other environmental information is crucial for intelligent decision-making and planning, as well as for assessing traversability risks in the autonomous driving functions of off-road vehicles. Compared to traditional perception solutions such as LiDAR and monocular cameras, stereo vision offers advantages like a simple structure, wide field of view, and robust spatial perception. However, its accuracy and computational cost in estimating complex off-road terrain environments still require further optimization. To address this challenge, this paper proposes a terrain environment estimating method for off-road vehicle anticipated driving area based on stereo
Zhao, JianZhang, XutongHou, JieChen, ZhigangZheng, WenboGao, ShangZhu, BingChen, Zhicheng
Over the last two decades many improvements have been made in stock car racing driver safety. One of these is the head surround, which is rigidly secured to and an integral part of the NASCAR (National Association for Stock Car Auto Racing, LLC) seating environment and serves as an effective restraint for head protection during lateral and rear impacts. However, previous head impact material specifications were optimized for moderate to severe impacts and did not address low severity impacts that occur frequently during typical driving, such as race restart vehicle nose-to-tail contact. This study focused on developing a test methodology for comprehensive evaluation of rear head surround materials for low, moderate and severe impacts. Specifically, this study aimed to formulate a specification that maintains previous material performance during high speed impacts, while decreasing head accelerations at low speed impacts. Quasi-static and dynamic drop tower testing of sample materials
Gray, Alexandra N.Harper, Matthew G.Mukherjee, SayakPatalak, John P.Gaewsky, James
With the increasing adoption of Zero-Gravity Seats in intelligent cockpits, there is a growing concern over the safety of occupants in reclined postures during collisions. The newly released anthropomorphic test device (ATD), THOR-AV, has modified the neck, spine, and pelvis structures to better match reclined postures. This study aims to investigate the changes in kinematic response and injury metrics for occupants in reclined postures, through high-speed frontal sled tests utilizing the THOR-AV. The tests were conducted using an adjustable rigid seat with a zero-gravity characteristic and an integrated three-point seat belt. Six tests were performed across four seat configurations: Standard, Semi-Reclined, Reclined, and Zero-gravity postures. The input acceleration pulse for these tests was derived from the equivalent double trapezoidal waveform of the Mobile Progressive Deformable Barrier (MPDB) test. Data from sensors and high-speed video were collected for analysis. The results
Wang, QiangLiu, YuFei, JingYang, XiaotingWang, PeifengBai, Zhonghao
Head injuries are a common cause of fatality and long-term impairment in child occupants in motor vehicle crashes. The National Highway Traffic Safety Administration (NHTSA) has developed the Large Omnidirectional Child (LODC) Anthropomorphic Test Device (ATD) where the head was designed to match pediatric biomechanical impact response targets from previous literature. The purpose of this study was to compare experimental and computational results for eight impact directions at 45-degree increments around the LODC head under two levels of impact severity: low and high, corresponding to nominal velocities of 3.08 mm/ms and 5.42 mm/ms, respectively. The experimental setup consists of the LODC head and neck assembly rigidly attached to a circular fixture plate and a hemispherical-shaped impactor 76.2 mm in diameter. The acceleration and angular velocity responses were measured and computed from the LODC finite element (FE) head CG and compared against the experimental data. Experimental
Challa, AbhishiktNoll, Scott
Sled crash tests are an important tool to develop automotive restraint systems. Compared with full-scale crash tests, the sled test has a shorter development cycle of the restraint system and lower cost. The objective of the present study is to create a cost-effective sled test methodology, calculate the optimal static yaw angle and loading curves, and analyze the motion response and injuries of the dummy in the small overlap crash test. The effectiveness of the proposed methodology was verified under two typical small overlap frontal crash modes: “energy-absorption” and “sideswipe”. The results show that with the calculated yaw angle α, the HIC was different from the small overlap crash model, but all remaining indices were within 5% of the injury criteria. All International Organization for Standardization (ISO) values between the combined accelerations of all parts of the dummy and those of the basic model exceeded 0.75, and some values were above 0.8. Therefore, the proposed sled
Yu, LiuChen, JianzhuoWan, Ming XinFan, TiqiangYang, PeilongNie, ZhenlongRen, LihaiCheng, James Chih
With the widespread application of the Automatic Emergency Braking System (AEB) in vehicles, its impact on pedestrian safety has received increasing attention. However, after the intervention of AEB, the kinematic characteristics of pedestrian leg collisions and their corresponding biological injury responses also change. At the same time, in order to accurately evaluate the pedestrian protection performance of vehicles, the current assessment regulations generally use advanced pedestrian protection leg impactors (aPLI) and rigid leg impactors (TRL) to simulate the movement and injury conditions of pedestrian legs. Based on this, in order to explore the collision boundary conditions and changes in injury between vehicles and APLI and TRL leg impactors under the action of AEB, this paper first analyzes the current passive and active assessment conditions. Secondly, the simulation software LS-DYNA is used to build a finite element model of APLI and TRL impactor-vehicle collisions to
Ye, BinHong, ChengWan, XinmingLiu, YuCheng, JamesLong, YongchenHao, Haizhou
Items per page:
1 – 50 of 5372