Browse Topic: Frontal collisions

Items (805)

A Sled Test Methodology for 25% Offset Crash Tests

2025-01-8737

04/01/2025

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, Liu, Chen, Jianzhuo, Wan, Ming Xin, Fan, Tiqiang, Yang, Peilong, Nie, Zhenlong, Ren, Lihai, Cheng, James Chih

The Influence of Reclined Seatback Angles on Occupant Injury Risks in Frontal Impacts

2025-01-8732

04/01/2025

The reclined seatbacks will be increasingly used with the advanced technologies of the intelligent automobile. The occupant collision protection must rise to the challenge facing to the new impact scenarios. It is necessary to understand the injury mechanisms of the reclined occupants in order to design the resistant system and testing protection regulations. In this study, simulation tests were conducted for the Frontal Full Width Impact (FRB) and the Mobile Progressive Deformable Barrier Frontal Impact (MPDB) as specified in the China New Car Assessment Programme (C-NCAP, 2021 version). The simulation used the biomechanical model of the 5th female occupant exhibiting the detailed anatomical structures and a seat model with large-angle seatback. The occupant injury risks and mechanisms with 25°, 45° and 60° seating postures were investigated by analyzing the kinematic and biomechanical parameters, and the influence of the seatback angle on occupant injury was discussed. The results

Wang, Yanxin, Pan, Ruyang, Lin, Yuyang, Liu, Yutao, He, Lijuan, Wang, Zhenqiang, zhu, he, Liu, Chong, Li, Kun, Lv, Wenle

Analysis and Comparison of Metrics to Assess Submarining Behavior with the Hybrid III 5th Percentile Dummy in the Rear Seat

2025-01-8711

04/01/2025

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 R, Jermakian, Jessica S, Edwards, Marcy A

A Study on Affections of Active Neck Muscle Force on Neck Injury Responses in Frontal Impact with Automatic Emergency Braking Conditions

2025-01-8742

04/01/2025

Neck injury is one of the most common injuries in traffic accidents, and its severity is closely related to the posture of the occupant at the time of impact. In the current era of smart vehicle, the triggered AEB and the occupant's active muscle force will cause the head and neck to be out of position which has significant affections on the occurrence and severity of neck injury responses. Therefore, it is very important to study the influences of active muscle force on neck injury responses in in frontal impact with Automatic Emergency Braking conditions. Based on the geometric characteristics of human neck muscles in the Zygote Body database, the reasonable neck muscle physical parameters were obtained firstly. Then a neck finite element model (FEM) with active muscles was developed and verified its biofidelity under various impact conditions, such as frontal, side and rear-end impacts. Finally, using the neck FEM with or without active muscle force, a comparative study was

Junpeng, Xu, Gan, Qiuyu, Jiang, Binhui, Zhu, Feng

Advanced Driver Assistance Systems (ADAS): Assessing the Efficacy of Non-Impact Testing for Evaluating the Performance of Frontal Collision Mitigation Technology

2025-01-8056

04/01/2025

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, Michelle, Easter, Casey, Koszegi, Giacomo, Alexander, Ross, Paradiso, Marc, Scally, Sean

Analyzing EV Battery Package Responses during Side Pole Impacts with Multiple Speeds and Locations

2025-01-8730

04/01/2025

Electric vehicles (EVs) have experienced significant growth, and the battery safety of EVs has drawn increased attention. However, the mechanical responses of battery during crashes have rarely been studied. Hence, the objective of this study was to understand EV battery package mechanics during side-pole crashes at different impact locations and speeds beyond regulated side-pole test with one specific speed and one location. An EV finite element (FE) model with a battery package was used. Side-pole impact simulations were conducted at four impact locations, including the baseline impact location according to side-pole impact regulation, plus three positions by moving the rigid pole 400 mm toward the back of the EV and moving the pole 400 and 800 mm toward the front of the EV. In addition, the impact velocities at 32, 50, and 80 km/h were simulated. Based on simulations, the peak relative displacement, the maximum change in gap between batteries, the maximum change in gap between the

Chen, Jian, Bian, Kewei, Mao, Haojie

The Influence of out-of-Position Displacement during Emergency Braking on Occupant Whiplash Injury in Subsequent Rear-End Collisions

2025-01-8720

04/01/2025

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, Jing, Qiu, Hang, Wang, Peifeng, Liu, Yu, Cheng, James Chih, Zhou, Qing, Tan, Puyuan

A Preliminary Study of Occupant Kinematics and Injuries in a Frontal Crash with Occupant Face-to-Face Scenario

2025-01-8736

04/01/2025

This paper investigates a novel seating arrangement where occupants face each other, focusing on occupant safety during a 56 km/h frontal impact, a standard test condition for assessing crashworthiness. A preliminary study was carried out, examining three distinct cases: a forward-facing 50th percentile occupant in third row seat, a rear-facing 50th percentile occupant in second row seat, and the interaction between these two occupant orientations. The study utilized both elastic flexible and rigid seat designs to analyze the impact on occupant kinematics and injury outcomes. The results demonstrate that the seating position has a significant influence on occupant injuries. Rear-facing occupants are primarily at risk due to seat design, whereas forward-facing occupants face a higher risk of injury from the increased space between occupants, lacking a reactive surface to mitigate impact forces. Notably, direct interaction between occupants did not result in severe injuries. However

Liu, Chong, Li, Kun, Liu, Yutao, Lv, Xiaojiang, Wang, Yonghui, Zhou, Dayong, Yang, Heping

Literature Review and Framework for Identifying Seat Belt Misuse and Misrouting in Frontal Collisions

2025-01-8721

04/01/2025

The effect of seat belt misuse and/or misrouting is important to consider because it can influence occupant kinematics, reduce restraint effectiveness, and increase injury risk. As new seatbelt technologies are introduced, it is important to understand the prevalence of seatbelt misuse. This type of information is scarce due to limitations in available field data coding, such as in NASS-CDS and FARS. One explanation may be partially due to assessment complexity in identifying misuse and/or misrouting. An objective of this study was to first identify types of lap-shoulder belt misuse/misrouting and associated injury patterns from a literature review. Nine belt misuse/misrouting scenarios were identified including shoulder belt only, lap belt only, or shoulder belt under the arm, for example, while belt misrouting included lap belt on the abdomen, shoulder belt above the breasts, or shoulder belt on the neck. Next, the literature review identified various methods used to assess misuse

Gu, Emily, parenteau, Chantal

Predicting Head Injury Criterion in Real-World Frontal Impacts

2025-01-8709

04/01/2025

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, Clyde, Tanczos, Rachel, Adanty, Kevin, Shimada, Sean

Application of 1.7GPa Martensitic Steel in Dash Lower Cross Member to Enhance Automotive Frontal Impact Safety

2025-01-8218

04/01/2025

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, Jongmin, Kim, Donghyun, Jang, Minho, Kim, Geunho, Seongho, Yoo, Kim, Kyu-Rae

Analysis of Traction Battery Damage Value Based on Frontal Impact

2025-01-7008

01/31/2025

As the adoption of new energy vehicles expands globally, the safety performance of their traction batteries has garnered significant attention due to the potential hazards posed by road debris and collisions. These safety concerns have become a major impediment to the advancement of these vehicles. This paper aims to analyze the impact resilience of traction batteries under frontal collision scenarios to evaluate their safety under specific conditions. A multi-level evaluation model for traction batteries is developed and integrated with computer tomography system analysis to investigate the extent of damage sustained by the battery system during frontal impacts. Utilizing a structured battery system damage assessment method, the study provides a quantitative analysis of the damage severity resulting from collisions. This offers both theoretical insights and practical guidance for the testing and evaluation of traction batteries.

Yan, Pengfei, Wang, Fang, Ma, Tianyi, Han, Ce, He, Gaiyun

Biofidelity Assessment of the GHBMC M50-O Seated in a Honda Accord Seat in a Rear-Facing Configuration during a High-Speed Frontal Impact

09-12-03-0014

12/10/2024

Vehicles equipped with automated driving systems (ADS) may have non-traditional seating configurations, such as rear-facing for front-row occupants. The objectives of this study are (1) to generate biomechanical corridors from kinematic data obtained from postmortem human subjects (PMHS) sled tests and (2) to assess the biofidelity of the Global Human Body Models Consortium (GHBMC) 50th male (M50-O) v6.0 seated in an upright (25-deg recline) Honda Accord seat with a fixed D-ring (FDR) in a 56 km/h rear-facing frontal impact. A phase optimization technique was applied to mass-normalized PMHS data for generating corridors. After replicating the experimental boundary conditions in the computational finite element (FE) environment, the performance of the rigidized FE seat model obtained was validated using LSTC Hybrid III FE model simulations and comparison with experiments. The most recent National Highway Traffic Safety Administration (NHTSA) Biofidelity Ranking System (BRS) method was

Pradhan, Vikram, Ramachandra, Rakshit, Stammen, Jason, Kracht, Corey, Moorhouse, Kevin, Bolte, John H., Kang, Yun-Seok

Intracranial Displacements due to Blunt Force Impact in a Postmortem Human Surrogate Brain

09-12-02-0011

11/12/2024

Prevention and diagnosis of traumatic brain injuries (TBI) are reliant on understanding the biomechanical response of the brain to external stimuli. Finite element models (FEM) and artificial head surrogates are becoming a common method of investigating the dynamic response of the brain to injurious impact and inertial stimuli. The accuracy and validity of these models is reliant on postmortem human subject (PMHS) research to produce biofidelic brain tissue responses. Previous PMHS research has been performed to measure intracranial pressures, displacements, and strains when subjected to impact and inertial loading; however, there remains a need for additional PMHS datasets to improve our understanding of the brain’s dynamics. The purpose of this study is to measure the relative brain–skull displacement in a PMHS specimen when subjected to blunt force impacts. A high-speed X-ray (HSXR) imaging system and embedded radiopaque elastomeric markers were used to record PMHS impacts at

Demiannay, Jean-Jacques, Rovt, Jennifer, Brannen, MacKenzie, Xu, Sheng, Kang, Gia, Yip, Ashley, Azadi, Amir Hossein, Dehghan, Parisa, Goodwin, Shannon, Taylor, Reggie, Poon, Katherine, Brien, Susan, Hoshizaki, Blaine, Karton, Clara, Petel , Oren

Summary of Poster Abstracts

09-12-02-0022

11/12/2024

Seventeen research posters were prepared and presented by student authors. The posters covered a wide breadth of works-in-progress and recently completed projects. Topics included a variety of body regions and injury scenarios: Biofidelity Corridors of Powered Two-Wheeler Rider Kinematics from Full-Scale Crash Testing Using Postmortem Human Subjects, Meringolo et al. Cervical Vertebral and Spinal Cord Injuries Remain Overrepresented in Rollover Occupants, Al-Salehi et al. The Effect of Surfaces on Knee Biomechanics during a 90-Degree Cut, Rhodes et al. Investigating the Variabilities in the Spinal Cord Injury in Pig Models Using Benchtop Test Model and Ultrasound Analyses, Borjali et al. Relationship between Tackle Form and Head Kinematics in Youth Football, Holcomb et al. Comparing Motor Vehicle Collision Injury Incidence between Pregnant and Nonpregnant Individuals: A Case–Control Study, Levine et al. Development of an Automated Pipeline to Characterize Full Rib Cage Shape

Bautsch, Brian T., Cripton, Peter A., Cronin, Duane

Effects of Head Restraint (HR) Interference on Child Restraint System (CRS) Performance in Frontal and Far-Side Impacts

2024-22-0003

10/10/2024

Forward-facing child restraint systems (FF CRS) and high-back boosters often contact the vehicle seat head restraint (HR) when installed, creating a gap between the back surface of the CRS and the vehicle seat. The effects of HR interference on dynamic CRS performance are not well documented. The objective of this study is to quantify the effects of HR interference for FF CRS and high-back boosters in frontal and far-side impacts. Production vehicle seats with prominent, removeable HRs were attached to a sled buck. One FF CRS and two booster models were tested with the HR in place (causing interference) and with the HR removed (no interference). A variety of installation methods were examined for the FF CRS. A total of twenty-four tests were run. In frontal impacts, HR interference produced small but consistent increases in frontal head excursion and HIC36. Head excursions were more directly related to the more forward initial position rather than kinematic differences caused by HR

Mansfield, Julie A.

Evaluation of DAMAGE Algorithm in Frontal Crashes

2023-22-0006

04/17/2024

With the current trend of including the evaluation of the risk of brain injuries in vehicle crashes due to rotational kinematics of the head, two injury criteria have been introduced since 2013 – BrIC and DAMAGE. BrIC was developed by NHTSA in 2013 and was suggested for inclusion in the US NCAP for frontal and side crashes. DAMAGE has been developed by UVa under the sponsorship of JAMA and JARI and has been accepted tentatively by the EuroNCAP. Although BrIC in US crash testing is known and reported, DAMAGE in tests of the US fleet is relatively unknown. The current paper will report on DAMAGE in NCAP-like tests and potential future frontal crash tests involving substantial rotation about the three axes of occupant heads. Distribution of DAMAGE of three-point belted occupants without airbags will also be discussed. Prediction of brain injury risks from the tests have been compared to the risks in the real world. Although DAMAGE correlates well with MPS in the human brain model across

Prasad, Priya, Barbat, Saeed D., Kalra, Anil, Dalmotas, Dainius J.

Comparison of the Responses of the Thorax and Pelvis of the GHBMC M50 -O Using Two Different Foam Materials in a High-Speed Rear Facing Frontal Impact Scenario

2024-01-2647

04/09/2024

Due to the lack of biofidelity seen in GHBMC M50-O in rear-facing impact simulations involving interaction with the seat back in an OEM seat, it is important to explore how the boundary conditions might be affecting the biofidelity and potentially formulate methods to improve biofidelity of different occupant models in the future while also maintaining seat validity. This study investigated the influence of one such boundary condition, which is the seat back foam material properties, on the thorax and pelvis kinematics and injury outcomes of the GHBMC 50th M50-O model in a high-speed rear-facing frontal impact scenario, which involves severe occupant loading of the seat back. Two different seat back foam materials were used – a stiff foam with high densification and a soft foam with low densification. The peak magnitudes of the T-spine resultant accelerations of the GHBMC M50-O increased with the use of soft foam as compared to stiff foam. However, the change in the average biofidelity

Pradhan, Vikram, Ramachandra, Rakshit, Kang, Yun Seok

Torque Vectoring for Lane-Changing Control during Steering Failures in Autonomous Commercial Vehicles

2024-01-2328

04/09/2024

Lane changing is an essential action in commercial vehicles to prevent collisions. However, steering system malfunctions significantly escalate the risk of head-on collisions. With the advancement of intelligent chassis control technologies, some autonomous commercial vehicles are now equipped with a four-wheel independent braking system. This article develops a lane-changing control strategy during steering failures using torque vectoring through brake allocation. The boundaries of lane-changing capabilities under different speeds via brake allocation are also investigated, offering valuable insights for driving safety during emergency evasions when the steering system fails. Firstly, a dual-track vehicle dynamics model is established, considering the non-linearity of the tires. A quintic polynomial approach is employed for lane-changing trajectory planning. Secondly, a hierarchical controller is designed. The upper layer employs a three-stage cascaded proportional integral controller

Lu, Ao, Li, Runfeng, Yinggang, Xu, Nie, Zexin, Li, Peilin, Tian, Guangyu

Frontal Crash Oriented Robust Optimization of the Electric Bus Body Frame Considering Tolerance Design

2024-01-2459

04/09/2024

For the design optimization of the electric bus body frame orienting frontal crash, considering the uncertainties that may affect the crashworthiness performance, a robust optimization scheme considering tolerance design is proposed, which maps the acceptable variations in objectives and feasibility into the parameter space, allowing for the analysis of robustness. Two contribution analysis methods, namely the entropy weight and TOPSIS method, along with the grey correlation calculations method, are adopted to screen all the design variables. Fifteen shape design variables with a relatively high impact are chosen for design optimization. A symmetric tolerance and interval model is used to depict the uncertainty associated with the 15 shape design variables of key components in the bus body frame to form an uncertainty optimization problem in the form of an interval, and a triple-objective robust optimization model is developed to optimize the shape design variables and tolerances

Yang, Xiujian, Liu, Beizhen

Occupant Kinematics During Chain-Collisions: Discrete vs Combined Collisions

2024-01-2489

04/09/2024

There is little prior research into chain-collisions, despite their relatively large contribution to injury and harm in motor-vehicle collisions. This study conducted a series of rear-impact, front-impact, and chain-collision impacts using a bumper car ride at an active amusement park as a proxy for automobiles. The purpose was to begin to identify the threshold time range when separate, discrete collisions transition into a hybrid or combined chain-collision mode and provide bases for future analyses. The test series consisted of rear impacts into an occupied target vehicle from a driven bullet vehicle; frontal impacts into a perimeter barrier (wall); chain-collisions consisting of a driven bullet vehicle striking an occupied primary target vehicle, which then collided with a non-occupied secondary target vehicle; and chain-collisions consisting of a driven bullet vehicle striking an occupied primary target vehicle which then collided with a wall. Time between collisions was adjusted

Bussone, William R., Koiler, Reza, Benda, Jamie, Carney, Nicholas, Geffard, Andres, Sam, Samantha

Analysis of Occupants by Seating Location, Restraint Use and Injury Risk in Tow-Away Crashes

2024-01-2752

04/09/2024

This study was conducted to assess the occupant restraint use and injury risks by seating position. The results were used to discuss the merit of selected warning systems. The 1989-2015 NASS-CDS and 2017-2021 CISS data were analyzed for light vehicles in all, frontal and rear tow-away crashes. The differences in serious injury risk (MAIS 3+F) were determined for front and rear seating positions, including the right, middle and left second-row seats. Occupancy and restraint use were determined by model year groups. Occupancy relative to the driver was 27% in the right-front (RF) and 17% in the second row in all crashes. About 39% of second-row passengers were in the left seat, 15% in the center seat and 47% in the right seat. Restraint use was lower in the second row compared to front seats. It was 43% in the right-front and 32% in the second-row seats in all crashes involving serious injury. Restraint use increased with model year groups. It was 63% in the ‘61-‘89 MY vehicles and 90

Parenteau, Chantal, Burnett, Roger

Effects of Anthropometry and Passive Restraint Deployment Timing on Occupant Metrics in Moderate-Severity Offset Frontal Collisions

2024-01-2749

04/09/2024

There are established federal requirements and industry standards for frontal crash testing of motor vehicles. Consistently applied methods support reliability, repeatability, and comparability of performance metrics between tests and platforms. However, real world collisions are rarely identical to standard test protocols. This study examined the effects of occupant anthropometry and passive restraint deployment timing on occupant kinematics and biomechanical loading in a moderate-severity (approximately 30 kph delta-V) offset frontal crash scenario. An offset, front-to-rear vehicle-to-vehicle crash test was performed, and the dynamics of the vehicle experiencing the frontal collision were replicated in a series of three sled tests. Crash test and sled test vehicle kinematics were comparable. A standard or reduced-weight 50th percentile male Hybrid III ATD (H3-50M) or a standard 5th percentile female Hybrid III ATD (H3-5F) was belted in the driver’s seating position. In the crash test

Courtney, Amy, Crosby, Charles, Miller, Bruce, Osterhout, Aaron, Walker, James, Gondek, Jonathon

Performance of Five-Point Seat Belt on Occupant Safety in Vehicle on Frontal Crash Test

2023-01-5169

02/23/2024

In day-to-day life, accidents do occur frequently all around the globe. It is difficult to prevent these accidents as they occur due to different reasons, which cannot be easily controlled. However, the fatal injuries occurring to passengers can be reduced by installing efficient safety systems in vehicles, which will help in saving the lives of mankind. Many safety systems are being installed in vehicles such as seat belt restraints, airbags, etc. Generally, three-point seat belts are installed in passenger vehicles for safety purposes. This type of seat belt doesn't arrest the entire motion of the occupant's body during vehicle crashes, which can lead to fatal injuries and sometimes even death during vehicle crashes. To buckle passengers with seats, we can use five-point seat belts which will help in mitigating the injuries as compared to three-point seat belts. In this paper, we evaluate the performance of five-point seat belts on occupant safety during vehicle crashes on flat rigid

Vinodh, T., Dineshkumar, C., Jeyakumar, P.D., Muthiya, Solomon Jenoris, Vinayagam, Nadana Kumar, Christu Paul, R., Dhanraj, Joshuva Arockia

Effectiveness of the Load Legs in Enhancing the Passive Safety of Rear-Facing Child Seats in Frontal Crash

2024-26-0343

01/16/2024

The passive safety performance of a child seat is modulated by the design features of the child seat and the vehicle interior. For example, in the rear-facing configuration, the child seat impacting front structures increases the head injury risk during a frontal crash. Therefore, this study evaluates the effectiveness of the load leg countermeasure in improving the child seat's overall kinematics and its capability to prevent the secondary impact on the vehicle interior structure in a severe frontal crash scenario. An in-depth, real-world crash investigation involving a properly installed rear-facing child seat impacting the center console was selected for the study where the infant sustained a severe brain injury. In addition, this crash is employed to choose the crash parameters for evaluating the effectiveness of the load leg countermeasure in a similar scenario. Finally, crash sled tests are conducted using the crash signature of the vehicle as obtained from the NHTSA NCAP rigid

Thorbole, Chandrashekhar

Comparison of the Knee–Thigh–Hip Response in Small Female ATDs with Female PMHS

09-11-02-0013

09/20/2023

Bilateral knee impacts were conducted on Hybrid III and THOR 5th percentile female anthropomorphic test devices (ATDs), and the results were compared to previously reported female PMHS data. Each ATD was impacted at velocities of 2.5, 3.5, and 4.9 m/s. Knee–thigh–hip (KTH) loading data, obtained either via direct measurement or through exercising a one-dimensional lumped parameter model (LPM), was analyzed for differences in loading characteristics including the maximum force, time to maximum force, loading rate, and loading duration. In general, the Hybrid III had the highest loading rate and maximum force, and the lowest loading duration and time to peak force for each point along KTH. Conversely, the PMHS generally had the lowest loading rate and maximum force, and the highest loading duration and time to peak force for each point along KTH. The force transfer from the knee to the femur was 79.2 ± 0.3% for the Hybrid III 5th female, 82.7 ± 0.4% for the THOR-05F, and 70.6 ± 1.7% for

Carpenter, Randolff L., Berthelson, Parker R., Donlon, John-Paul, Forman, Jason L.

Improved Predictions of Human Rib Structural Properties Using Bone Mineral Content

09-11-02-0017

09/20/2023

Rib fractures are associated with high rates of morbidity and mortality. Improved methods to assess rib bone quality are needed to identify at-risk populations. Quantitative computed tomography (QCT) can be used to calculate volumetric bone mineral density (vBMD) and bone mineral content (BMC), which may be related to rib fracture risk. The objective of this study was to determine if vBMD and BMC from QCT predict human rib structural properties. 127 mid-level (5th–7th) ribs were obtained from adult female (n = 67) and male (n = 60) postmortem human subjects (PMHS). Isolated rib QCT scans were performed to calculate vBMD and BMC. Each rib was subsequently tested to failure in a dynamic simulated frontal impact and structural properties, peak force (FPeak), percent displacement (δPeak), linear structural stiffness (K), and total energy (UTot) were calculated. vBMD demonstrated no significant differences between sexes (p > 0.05); however, males had a higher BMC than females (p < 0.001

Haverfield, Z.A., Hunter, R.L., Kang, Y.S., Patel, A.B., Agnew, A.M.

Influence of Pre-Crash Vehicle Maneuvers on Front Passenger Safety Performance Response

09-11-02-0021

09/20/2023

Pre-crash vehicle maneuvers are known to affect occupant posture and kinematics, which consequently may influence injury risks during a collision. In this study, the influence of pre-crash vehicle maneuvers on the injury risks of front-seated occupants during a frontal crash was numerically evaluated. A generic buck vehicle model was developed based on a publicly available FE model, which included the vehicle interior and the front passenger airbag (PAB). The pre-crash phase was simulated using specific rigid-body human models with active joints (GHBMCsi-pre models) developed based on exterior shapes of the simplified deformable human model (GHBMCsi) representing a 50th male subject. Two pre-crash maneuvers representing (1) a generic 1g braking and (2) turning-and-braking scenarios were simulated. Then, the kinematics data of belted GHBMCsi-pre models were transferred using a developed switch algorithm to the corresponding GHBMCsi models, which can predict occupant injury risks

Dahiya, Akshay, Untaroiu, Costin

Letter from the Special Issue Editors

09-11-02-0009

09/20/2023

Letter from the Special Issue Editors

Mueller, Becky, Bautsch, Brian, Mansfield, Julie

Restraint System Optimizations Using Diverse Human Body Models in Frontal Crashes

09-11-02-0018

09/20/2023

Objective: This study aimed to optimize restraint systems and improve safety equity by using parametric human body models (HBMs) and vehicle models accounting for variations in occupant size and shape as well as vehicle type. Methodology: A diverse set of finite element (FE) HBMs were developed by morphing the GHBMC midsize male simplified model into statistically predicted skeleton and body shape geometries with varied age, stature, and body mass index (BMI). A parametric vehicle model was equipped with driver, front passenger, knee, and curtain airbags along with seat belts with pretensioner(s) and load limiter and has been validated against US-NCAP results from four vehicles (Corolla, Accord, RAV4, F150). Ten student groups were formed for this study, and each group picked a vehicle model, occupant side (driver vs. passenger), and an occupant model among the 60 HBMs. About 200 frontal crash simulations were performed with 10 combinations of vehicles (n = 4) and occupants (m = 8

Yang, Zhenhao, Desai, Amoghsidd, Boyle, Kyle, Rupp, Jonathan, Reed, Matthew, Hu, Jingwen

Analysis of Kinetic Metrics in Submarining vs Non-Submarining Conditions for a 6YO Pediatric Human Body Model in Frontal Impacts

09-11-02-0020

09/20/2023

Field data has shown that belt-positioning boosters help reduce the risk of injury to children in a crash. This study builds on prior submarining work (Slusher et al. 2022) and aims to analyze kinetic metrics (which can be easily recorded from anthropomorphic test devices in crash tests) in submarining and non-submarining conditions for a 6-year-old pediatric human occupant in frontal crashes.

Williams, Bethany, Maheshwari, Jalaj

Comparison of Head, Neck, and Chest Injury Risks between Front- and Rear-Seated Hybrid III 50th-Percentile Male ATDs in Matched Frontal NCAP Tests

09-12-01-0001

09/19/2023

The objective of this study was to compare head, neck, and chest injury risks between front and rear-seated Hybrid III 50th-percentile male anthropomorphic test devices (ATDs) during matched frontal impacts. Seven vehicles were converted to rear seat test bucks (two sedans, three mid-size SUVs, one subcompact SUV, and one minivan) and then used to perform sled testing with vehicle-specific frontal NCAP acceleration pulses and a rear seated (i.e., second row) Hybrid III 50th male ATD. Matched front seat Hybrid III 50th male ATD data were obtained from the NHTSA Vehicle Crash Test Database for each vehicle. HIC15, Nij, maximum chest acceleration, and maximum chest deflection were compared between the front and rear seat tests, as well as between vehicles with conventional and advanced three-point belt restraint systems in the rear seat. Additionally, a modified version of the NCAP frontal star rating was calculated for the front and rear seat tests. All injury metrics, except for chest

Bianco, Samuel T., Albert, Devon L., Guettler, Allison J., Hardy, Warren N., Kemper, Andrew R.

Occupant Kinetics and Muscle Responses of Relaxed and Braced Small Female and Midsize Male Volunteers in Low-Speed Frontal Sled Tests

09-11-03-0012

07/28/2023

Previous volunteer studies focused on low-speed frontal events have demonstrated that muscle activation (specifically pre-impact bracing) can significantly affect occupant response. However, these tests do not always include a sufficient number of small female volunteers to compare their unique responses to the typically studied midsize male population. The purposes of this study were to quantify the occupant kinetics and muscle responses of relaxed and braced small female and midsize male volunteers during low-speed frontal sled tests and to compare between muscle states and demographic groups. Small female and midsize male volunteers experienced multiple low-speed frontal sled tests consisting of two pulse severities (1 g and 2.5 g) and two muscle states (relaxed and braced) per pulse severity. The muscle activity of 30 muscles (15 bilaterally) and reaction forces at the volunteer-test buck interfaces and seat belt were measured before and during each sled test. Compared to the

Chan, Hana, Albert, Devon L., Gayzik, F. Scott, Kemper, Andrew R.

Frontal Crash Reconstruction Compared to Event Data Recorders in the Crash Investigation Sampling System Database and the Effect on Injury Risk Models

2023-01-5043

07/17/2023

This study compares statistical models for frontal crash injuries based on delta-v data reported by the vehicle event data recorder (EDR) with injury probability models based on delta-v reconstructed by Crash Investigation Sampling System (CISS) investigators. Injury probabilities and their follow-on use in advanced automatic crash notification (AACN) systems have traditionally been based on delta-v obtained through accident reconstruction of field crashes in the National Automotive Sampling System Crash Data System (NASS-CDS) database. Field delta-v from EDRs in the CISS database is an alternative source of information for crash injury probability modeling. In this study, frontal impact injury risk probabilities computed from EDR and reconstructed delta-v were compared. All data came from the years 2017–2021 of the CISS database, which contains EDR downloads and also reconstructed delta-v using crush measurements and NHTSA’s WinSmash software. On average, CISS reconstructions

Watson, Richard A., Bonugli, Enrique, Greenston, Mathew

Investigation of Potential Injury Patterns and Occupant Kinematics in Frontal Impact with PMHS in Reclined Postures

2022-22-0001

06/27/2023

The reality of the autonomous vehicle in a near future is growing and is expected to induce significant change in the occupant posture with respect to a standard driving posture. The delegated driving would allow sleeping and/or resting in a seat with a reclined posture. However, the data in the literature are rare on the body kinematics, human tolerance, and injury types in such reclined postures. The current study aims at increasing the knowledge in the domain and providing useful data to assess the relevance of the standard injury assessment tools such as anthropomorphic test devices or finite element human body models. For that purpose, a test series of three male Post-Mortem Human Subjects (PMHS) were performed in frontal impact at a 13.4 m/s delta V. The backseat inclination was 58 degrees with respect to the vertical axis. The semi-rigid seat developed by Uriot et al. (2015) was used with a stiffer seat ramp. The restraint was composed of a lap belt equipped with two 3.5 kN load

Baudrit, Pascal, Uriot, Jérôme, Richard, Olivier, Debray, Matthieu

Obese Occupant Response in Reclined and Upright Seated Postures in Frontal Impacts

2022-22-0002

06/27/2023

The American population is getting heavier and automated vehicles will accommodate unconventional postures. While studies replicating mid-size and upright fore-aft seated occupants are numerous, experiments with post-mortem human subjects (PMHS) with obese and reclined occupants are sparse. The objective of this study was to compare the kinematics of the head-neck, torso and pelvis, and document injuries and injury patterns in frontal impacts. Six PMHS with a mean body mass index of 38.2 ± 5.3 kg/m2 were equally divided between upright and reclined groups (seatback: 23°, 45°), restrained by a three-point integrated belt, positioned on a semi-rigid seat, and exposed to low and moderate velocities (15, 32 km/h). Data included belt loads, spinal accelerations, kinematics, and injuries from x-rays, computed tomography, and necropsy. At 15 km/h speed, no significant difference in the occupant kinematics and evidence of orthopedic failure was observed. At 32 km/h speed, the primary

Somasundaram, Karthik, Humm, John R., Yoganandan, Narayan, Hauschild, Hans, Driesslein, Klaus, Pintar, Frank A.

A Comparison of the Mid-Size Male THOR and Hybrid III ATDs in Vehicle Frontal Crash Tests

2022-22-0005

06/27/2023

In order to evaluate the THOR-50M as a front impact Anthropomorphic Test Device (ATD) for vehicle safety design, the ATD was compared to the H3-50M in matching vehicle crash tests for 20 unique vehicle models from 2 vehicle manufacturers. For the belted driver condition, a total of fifty-four crash tests were investigated in the 56.3 km/h (35 mph) front rigid barrier impact condition. Four more tests were compared for the unbelted driver and right front passenger at 40.2 km/h (25 mph) in the flat frontal and 30-degree right oblique rigid barrier impact conditions. The two ATDs were also evaluated for their ability to predict injury risk by comparing their fleet average injury risk to Crash Investigation Sampling System (CISS) accident data for similar conditions. The differences in seating position and their effect on ATD responses were also investigated. This study showed that the belted THOR-50M injury responses were higher than the H3-50M by 25%-180%, in all reported ATD responses

O’Connor, Chris, Kim, Agnes, Barrette, Tim, Dix, Jeff

TOC

2022-22-0009

06/27/2023

TOC

Tobolski, Sue

Restitution and Crash Pulse Duration from Low-Speed Crash Tests

2023-01-0617

04/11/2023

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, Marc, McDowell, Eric

Evaluation of Occupant Kinematics and Kinetics during Moderate Severity Simulated Frontal Impacts with and without Frontal Airbag Deployment

2023-01-0559

04/11/2023

Airbag and seat belt pretensioner deployment characteristics depend on multiple factors, such as the magnitude, direction, and rate of vehicle deceleration as detected by vehicle crash sensors and evaluated by vehicle-specific algorithms. Frontal airbag and pretensioner deployments are likely to be commanded during frontal crash events with high initial vehicle deceleration typically associated with high vehicle change in velocity (delta-V). However, within a range of moderate changes in vehicle speeds, referred to as the “gray zone,” a vehicle-specific algorithm may or may not command deployment depending on crash pulse parameters and occupant sensing, among other items. Publicly available testing in the moderate-speed range is lacking and would be useful to evaluate the effects of airbag and pretensioner deployment on occupant kinematics and loading. In this study, sled tests were performed using a standard passenger vehicle buck simulating frontal deceleration impact events in a

Sharpe, Sarah S., Grijalva, Sandra, Allin, Leigh, Courtney, Amy, Toney-Bolger, Megan, Pokutta-Paskaleva, Anastassia, Crosby, Charles L., Carhart, Michael

Event Data Recorder

J1698_202303 (Current)

03/01/2023

This SAE Recommended Practice describes common definitions and operational elements of Event Data Recorders. The SAE J1698 series of documents consists of the following: SAE J1698-1 - Event Data Recorder - Output Data Definition: Provides common data output formats and definitions for a variety of data elements that may be useful for analyzing vehicle crash and crash-like events that meet specified trigger criteria. SAE J1698-2 - Event Data Recorder - Retrieval Tool Protocol: Utilizes existing industry standards to identify a common physical interface and define the protocols necessary to retrieve records stored by light duty vehicle Event Data Recorders (EDRs). SAE J1698-3 - Event Data Recorder - Compliance Assessment: Defines procedures that may be used to validate that relevant EDR output records conform with the reporting requirements specified in Part 563, Table 1 during the course of FMVSS-208, FMVSS-214, and other applicable vehicle level crash testing.

Event Data Recorder Committee

Development of a New Human Thoracic Equivalent Model during Frontal Impact

09-11-02-0007

01/13/2023

Human thoracic injury under frontal collisions is an inevitable problem in vehicle safety research. Compared with the Multiple Rigid-Body Models (MRBMs) and Finite Element Human Body Models (FEHBMs), Mathematical Equivalent Models (MEMs) can not only provide important data but also improve the research efficiency. The current thoracic MEMs usually adapted the mechanical isolation method to isolate the thorax from the human body; therefore, the effects of the head, neck, and lower body internal organs on the mechanical responses of the thorax are not considered. In this article, a new thoracic MEM, named as Improved Consistent Lobdell Model (ICLM), is developed based on the concentrated mass-spring-damping system to consider the energy absorbed by the deformation of the internal soft tissue and the motion hysteresis of the head, neck, and lower body. Thorax equivalent stiffness curve predicted by the ICLM has a good fit with the corridor obtained by the Post-Mortem Human Subjects (PMHS

Liu, Zhixin, Zheng, Hong, Ma, Weijie

Passive Safety Systems Analysis for Protecting the Second-Row Unbelted Occupants in Frontal Collision

2022-28-0400

10/05/2022

Though there are active safety features in the passenger cars, unfortunately not all accidents are avoidable. Airbags are the passive safety feature which avoid occupants in colliding with the car interiors and help to mitigate the fatal injuries. Trend and interest in the recent times is to study the occupant injury for front row seats. The second-row occupants are usually protected with the passive safety systems by Seat belts, Inflatable Curtain airbags, seat airbags, Windshield airbags etc. These are installed in the side and rear areas of car to pass on the regulations like FMVSS, ECE and other global standards. This particular case study is to evaluate or say how effective are the occupants in the second rows if they are unbelted. In few of the crash tests and experiment of frontal impact collision, the child dummies will be placed on female dummy lap without wearing the seat belt. In this, we see the second-row occupants will be seriously injured in most of the cases. Though the

Srinivasa, Praveen, Sundaram, Balachandar, Patil, Shubham

Ambulance Patient Compartment Structural Integrity Test to Support SAE J3027 Compliant Litter Systems

J3102_202206 (Current)

06/21/2022

This SAE Recommended Practice describes the dynamic and static testing procedures required to evaluate the integrity of the ambulance substructure, to support the safe mounting of an SAE J3027 compliant litter retention device or system, when exposed to a frontal, side or rear impact (i.e., a crash impact). Its purpose is to provide manufacturers, ambulance builders, and end-users with testing procedures and, where appropriate, acceptance criteria that to a great extent ensure the ambulance substructure meets the same performance criteria across the industry. Prospective manufacturers or vendors have the option of performing either dynamic testing or static testing. Descriptions of the test set-up, test instrumentation, photographic/video coverage, test fixture, and performance metrics are included.

Truck Crashworthiness Committee

Ambulance Interior Storage Compartment Integrity

J3058_202206 (Current)

06/21/2022

This SAE Recommended Practice describes the dynamic testing procedures required to evaluate the integrity of patient compartment interior Storage Compartments such as cabinets, drawers, or refillable supply pouch systems when exposed to a frontal, side or rear impact (i.e., a crash impact). Its purpose is to provide component manufacturers, ambulance builders, and end-users with testing procedures and, where appropriate, acceptance criteria that, to a great extent, ensure interior Storage Compartments or systems meet the same performance criteria across the industry. Descriptions of the test set-up, test instrumentation, photographic/video coverage, test fixture, and performance metrics are included.

Truck Crashworthiness Committee

Ambulance Litter Integrity, Retention, and Patient Restraint

J3027_202206 (Current)

06/21/2022

This SAE Recommended Practice describes the testing procedures required to evaluate the integrity of a ground ambulance-based patient litter, litter retention system, and patient restraint when exposed to a frontal, side or rear impact. Its purpose is to provide litter manufacturers, ambulance builders, and end-users with testing procedures and, where appropriate, acceptance criteria that, to a great extent ensures the patient litter, litter retention system, and patient restraint utilizes a similar dynamic performance test methodology to that which is applied to other vehicle seating and occupant restraint systems. Descriptions of the test set-up, test instrumentation, photographic/video coverage, test fixture, and performance metrics are included.

Truck Crashworthiness Committee

Occupant Restraint and Equipment Mounting Integrity – Frontal Impact Ambulance Patient Compartment

J2917_202206 (Current)

06/20/2022

This SAE Recommended Practice describes the test procedures for conducting frontal impact occupant restraint and equipment mounting integrity tests for ambulance patient compartment applications. Its purpose is to describe crash pulse characteristics and establish recommended test procedures that will standardize restraint system and equipment mounting testing for ambulances. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.

Truck Crashworthiness Committee

Low Speed Thorax Impact Test Procedure for the HIII5F Dummy

J2878_202206 (Current)

06/09/2022

This procedure establishes a recommended practice for performing a Low Speed Thorax Impact Test to the Hybrid III Small Female Anthropomorphic Test Device (ATD or crash dummy). This test was created to satisfy the demand by the industry to have a certification test which results in peak chest deflection similar to current full vehicle, frontal impact tests. An inherent problem exists with the current certification procedure because the normal (6.7 m/s) thorax impact test has test results for peak chest deflection that are greater than those currently seen in full vehicle, frontal tests. The intent of this document is to develop a low speed thorax certification procedure for the H-III5F dummy with a 3.0 m/s impact similar to the SAE J2779 procedure for the H-III50M dummy.

Dummy Testing and Equipment Committee

THOR-05F Response in Sled Tests Inducing Submarining and Comparison with PMHS Response Corridors

2021-22-0005

05/20/2022

The Test Device for Human Occupant Restraint (THOR) is an advanced crash test dummy designed for frontal impact. Originally released in a 50th percentile male version (THOR-50M), a female 5th version (THOR-05F) was prototyped in 2017 (Wang et al., 2017) and compared with biofidelity sub-system tests (Wang et al., 2018). The same year, Trosseille et al. (2018) published response corridors using nine 5th percentile female Post Mortem Human Subjects (PMHS) tested in three sled configurations, including both submarining and non-submarining cases. The goal of this paper is to provide an initial evaluation of the THOR-05F biofidelity in a full-scale sled test, by comparing its response with the PMHS corridors published by Trosseille et al. (2018). Significant similarities between PMHS and THOR-05F were observed: as in Trosseille et al. (2018), the THOR-05F did not submarine in configuration 1, and submarined in configurations 2 and 3. The lap belt tension and seat forces were similar in

Richard, Olivier, Lebarbé, Matthieu, Uriot, Jérôme, Trosseille, Xavier, Petit, Philippe, Wang, Z. Jerry, Lee, Ellen

Biofidelity Evaluation of THOR-50M in Rear-Facing Seating Configurations Using an Updated Biofidelity Ranking System

09-10-02-0013

04/15/2022

Vehicles with automated driving systems (ADS) may allow nontraditional seating arrangements, such as a reclined seat that is rear facing in a frontal impact. Currently, there is not a widely accepted, commercially available, anthropomorphic test device (ATD) that is designed for a reclined, rear-facing, high-speed crash situation. To begin to identify what modifications are needed for candidate ATDs to exhibit human-like characteristics in these nontraditional scenarios, ATDs should be tested and compared to available postmortem human subject (PMHS) biofidelity response corridors in these seating arrangements. The first objective of this study was to present and discuss updates to the Biofidelity Ranking System (BRS). The second objective was to use the updated BRS to evaluate the responses of the THOR 50th percentile male (Test device for Human Occupant Response, THOR-50M) ATD in the rear-facing condition. Quantitative comparisons were made between the THOR responses and biofidelity

Hagedorn, Alena, Stammen, Jason, Ramachandra, Rakshit, Rhule, Heather, Thomas, Colton, Suntay, Brian, Kang, Yun-Seok, Kwon, Hyun Jung, Moorhouse, Kevin, Bolte IV, John H.

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