Browse Topic: Protective systems

Items (4,086)

Influence of Restraint System Angles on Impact Response and Protection of Child Occupants in Vertical Crash Conditions

2026-99-0413

8/28/2026

Focusing on the protection needs of child occupants in the scenario of aircraft vertical crashes, a finite element calculation model based on the cabin structure of a certain type of small electric aircraft was established. The child seat restraint system was coupled with the THUMS 3YO human body model, and the vertical 15 g condition meeting the requirements of Article 23.562 of CCAR-23-R3 was simulated. The influence law of the safety belt restraint angles (formed by different safety belt routing positions) on the dynamic response and injury indicators of child occupants was explored. To verify the rationality of the simulation results, a physical impact experiment was conducted using a Hybrid III 3YO child dummy and the same type of child seat, with key indicators (e.g., head acceleration, lumbar load) measured and compared with simulation data. The analysis results show that the effect of the safety belt restraint angle on the overall protective performance is less pronounced under vertical conditions, but a clear trend is observed: when the angle is in the range of 76°~84°, the head acceleration is relatively low and the brain tissue injury indicators are in the optimal state, which can effectively reduce the risk of head and neck injuries; when the restraint angle increases to 92°, the lumbar axial load and lung strain increase significantly, indicating a detrimental effect. The results of this study clarify the differences in the protective performance of child seats under different restraint angles, and provide a theoretical basis and technical guidance for the layout of safety belt anchors of aircraft seats and the optimal design of child seats.

Wang, Yafeng, Guo, Pan, Li, Weiliang, Shi, Xiaopeng

Lightweight Research on CFRP Bumper Impact Beam

2026-99-0411

8/28/2026

As a critical component in vehicular passive safety systems, the automotive bumper beam significantly influences overall crash safety performance and lightweight potential. This study presents a comprehensive investigation into the lightweight design of a carbon fiber reinforced polymer (CFRP) bumper beam, systematically substituting a conventional aluminum alloy component based on the principle of equivalent bending stiffness. The research methodology integrates finite element modeling, design of experiments, and multi-objective decision-making to optimize crashworthiness. Initial design replaced the 3 mm aluminum beam with a 2.4 mm CFRP configuration using a [0°, 45°, 90°, -45°] ply sequence, demonstrating maintained structural integrity with substantial mass reduction potential. Through Latin Hypercube Sampling, 50 design configurations incorporating variations in panel thicknesses (five distinct sections) and ply orientation sequences were generated and evaluated under an 8 km/h frontal impact simulation. Crashworthiness was assessed through four key indicators: mass, specific energy absorption (SEA), maximum intrusion distance (Dm), and peak impact force (Fm). The entropy weight method objectively determined indicator weights, revealing maximum intrusion (49.27%) as the most critical factor, followed by mass (32.75%), peak force (9.75%), and SEA (8.23%). Subsequently, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was employed to comprehensively evaluate and rank all design alternatives. The optimized CFRP configuration (Scheme #38) achieved remarkable performance: 69.1% mass reduction (from 4.505 kg to 1.392 kg), 379.6% improvement in specific energy absorption, 12.6% reduction in peak impact force, while maintaining intrusion within acceptable design limits. This research establishes a robust framework for CFRP bumper beam optimization, successfully balancing lightweight objectives with enhanced crashworthiness, providing valuable insights for automotive lightweight safety component development.

Wang, Yizhi, Zhong, Rong, Long, Jiangqi

Modeling and Simulation of the Quick Discharge Hydraulic System of an Internal Mixer

2026-99-0305

8/14/2026

The hydraulic system of the mechanical lever locking device of the internal mixer and the hydraulic system of the gear rack swing hydraulic cylinder are developed. The AMESim simulation models of the two systems are established, and the simulation parameters of each hydraulic element are reasonably set. Firstly, the relationship between the opening time of the mechanical lever locking device of the internal mixer and the charging volume and pressure of the accumulator is analyzed. It is found that the locking time of the mechanical lever locking device of the internal mixer needs about 10 s, while the unlocking time is less than 0.05 s. The unlocking and rubber discharging speed is very fast, and the opening time of the mechanical lever locking device of the internal mixer will become shorter when the pressure or volume of the accumulator air bag becomes larger; Through the analysis of the hydraulic system of the rack and pinion swing hydraulic cylinder, it is obtained that when the air bag volume of the accumulator is 7.557 L, the displacement of the piston rod of the rack and pinion swing hydraulic cylinder rises fastest, which is shortened from 20 s to about 15 s; The greater the air bag pressure of the accumulator is, the faster the displacement of the piston rod of the gear rack swing hydraulic cylinder rises, which is shortened from 20 s to 18 s.

Zhang, Haoqiang, Cai, Liu

Pelvis Lap Belt Engagement of Small-Sized Females in Frontal Impacts Using Seat-Integrated Restraints and Vehicle Seats for Alternative Seating Positions

2026-22-0008

8/14/2026

Non-traditional vehicle seating postures challenge traditional occupant protection paradigms that promote pelvis lap belt engagement. Seat-integrated restraints may promote pelvis lap belt engagement in alternative seating postures but have not been evaluated with post-mortem human subjects (PMHS) in vehicle seats. The goal of this research was to perform three 38.8 g, 56 km/h frontal impact sled tests with small-sized female PMHS in a crash environment with a vehicle seat designed for alternative seating positions. PMHS pelvis kinematics, lap belt engagement, and submarining response were compared to that of the Hybrid III 5th female (HIII-5F) in the same environment. The seat was in the rearmost seat track position, reclined 40° from vertical, and incorporated a leg rest, which elevated the feet off the floor. A seat cushion airbag (SCAB), large passenger airbag (PAB), shoulder belt pretensioner (SB P/T), and seat-integrated belt (BIS) were incorporated into the testing environment. The SCAB restricted initial downward translation of the pelvis and induced 7.7°–11.8°of initial pelvis rearward rotation. Lap belt loading of the abdominal soft tissue occurred in each test via three distinct interactions: (1) initial pelvis lap belt engagement followed by pelvis fracture and subsequent submarining; (2) lack of initial pelvis engagement and direct abdominal loading; (3) initial pelvis lap belt engagement followed by submarining. In a matched test environment, the HIII-5F did not submarine nor reproduce the entire lap belt pelvis interactions observed by the PMHS. Future research must develop better tools for predicting lap belt engagement in alternative seating positions.

Newman, Rachel, Shin, Jeesoo, Sochor, Sara, Morgan, Neal R., Gepner, Bronislaw D., Kerrigan, Jason R., Kim, Yongtae, Kim, Sung Rae

Mechanical Structure Design and Dynamics Simulation of an Exoskeleton Leg Rehabilitation Robot

2026-99-0902

8/7/2026

In response to the challenges of training and rehabilitation for patients with leg dysfunction, this research focuses on two core requirements: “bionic adaptation” and “safety assistance”. It introduces a novel exoskeleton leg rehabilitation robot designed to support diverse rehabilitation exercises for individuals with leg disabilities during therapy. The robot system consists of a lumbar support structure, thigh mechanical components, calf mechanical components, leg fixation straps, and foot mechanical structures, and achieves multi degree of freedom motion simulation through three main joints: hip joint, knee joint, and ankle joint. Each mechanical leg has three independent degrees of freedom, which can effectively simulate the natural movements of the human lower limb, such as flexion, extension, abduction, etc., during the gait cycle, thus meeting the functional needs of patients for different movement modes during rehabilitation training. On the basis of structural design, this study further utilizes multi-body dynamics simulation software ADAMS to conduct kinematic and dynamic analysis of the exoskeleton robot. By simulating the joint torque of the exoskeleton legs under ideal working conditions, the rationality and smoothness of the mechanism design are verified. The simulation results not only reflect the performance of the robot in typical rehabilitation actions, but also provide a theoretical basis and data support for the selection and parameter matching of key execution components (such as servo motors, reducers, etc.), laying an important foundation for the physical development and control strategy optimization of the robot system.

Mu, Xiaoqi, Ma, Chao, Li, Weijie, Pu, Shuai, Liu, Jiaqi, Wang, Ruiyin, Zhang, Xiaodong

Comparison of Female and Male Post Mortem Human Subject Kinematic Responses and Injuries in Rear-Facing Seat Configurations in High-Speed Frontal Impacts

2026-22-0007

7/28/2026

This study investigates female post-mortem human subject (PMHS) responses and injuries, comparing them to previously published data from male PMHS tested at a change in velocity (delta-V) of 56 kph in high-speed rear-facing frontal- impact (HSRFFI) scenarios. Twelve small female PMHS were subjected to the same HSRFFI pulse. The subjects were positioned in reinforced production seats, identical to those from the previous male PMHS studies, and set to recline angles of either 25 or 45 degrees. Instrumentation was used to measure kinematics of the head, spine, pelvis, and ribs. Whole-body kinematics were recorded using motion capture. Female PMHS consistently showed lower head restraint, seatback, and lap belt loads compared to males across all test conditions (Bio Rank System [BRS] scores >1.0), with BRS scores for head restraint forces as high as 4.0. While head and T1 kinematics were consistent with males in all-belt-to-seat (ABTS) conditions (BRS < 1.0), significant differences were found in other body regions (BRS>1.0). Female PMHS had larger head forward rotation and smaller pelvis Z-axis displacement (less ramping) than males in the fixed D-ring (FDR) conditions, leading to major discrepancies (BRS>2.0). In addition, female chest deflection was smaller in one FDR condition (BRS=1.98), and tibia acceleration onset was earlier. Female PMHS sustained severe to critical rib fractures (Abbreviated Injury Scale [AIS]3-5) similar to males. However, five females in the FDR conditions and one in the ABTS condition sustained sacral fractures, an injury not seen in males. Females also had a higher frequency of lower extremity fractures (7 of 12) and vertebral body fractures (7 of 12) compared to males. These findings suggest that existing male PMHS data may not adequately predict responses and injury risks for female PMHS, emphasizing the need for female-specific biomechanical data to enhance safety tools and models in HSRFFI scenarios.

Kang, Yun-Seok, Baker, Gretchen H., Ramachandra, Rakshit, Marcallini, Angelo, Kwon, Hyunjung, Foster, Craig D., Moorhouse, Kevin, Agnew, Amanda M., Bolte, John H.

Dynamic and Static Optimization Design of Car-seat Structure

2026-99-1614

7/24/2026

A car seat is one of the most critical components of passive safety. On the basis of the safety of car seats, this paper focuses on optimizing the design of the seat frame and achieving a lightweight design under various dynamic and static loading conditions. The optimization results are verified through physical experiments, which demonstrate the correctness and feasibility of the proposed design method. These experiments also provide research ideas for the optimization design of the seat structure and a certain reference value for the engineering application of the seat.

Shao, Youlin, Ni, Weiyu, Chen, Daojiong

Crashworthiness of WC19 Wheelchairs in Vertical Dynamic Aircraft Seating Tests

09-14-02-0004

7/9/2026

Currently, people who use wheelchairs are not permitted to use their own wheelchairs as seats on commercial aircraft. To advance equitable aircraft travel for these passengers, we need to determine whether wheelchairs would be safe seating for their occupants and not pose a safety hazard for other passengers in case of emergency landing. We hypothesized that wheelchairs meeting the voluntary standards for vehicle crashworthiness (Rehabilitation Engineering Society of North America [RESNA] Section 19 Wheelchairs Used as Seats in Motor Vehicles [WC19]) would be able to pass the Federal Aviation Administration (FAA) vertical crashworthiness standards for aircraft seating. Wheelchairs were secured using surrogate 4-point strap tiedowns using the geometry specified by WC19. The FAA Hybrid III anthropomorphic test device (FH3 ATD) was restrained by both the wheelchair-attached lap belt and a vehicle-mounted lap belt identified as necessary to pass FAA dynamic horizontal test requirements. For the dynamic vertical testing with the wheelchairs oriented 60 degrees relative to horizontal, modeling demonstrated the suitability of using the trapezoidal pulse achieved with the UMTRI sled produced rather than the typical triangular shaped FAA pulse. Of the five manual and three power wheelchairs tested, four had broken components that would not impede emergency exit, four did not have visible damage, and the FH3 remained within the seat in all tests. The three power wheelchairs did not meet lumbar compression requirements. Based on these results, it may be feasible for people to use their own WC19-compliant wheelchairs on aircraft when secured to the aircraft with 4-point strap tiedown systems, supplemented by an occupant lap belt anchored to the aircraft, notwithstanding the lumbar force requirement.

Manary, Miriam A., Orton, Nichole Ritchie, Vallier, Tyler, Boyle, Kyle J., Klinich, Kathleen DeSantis

Personal Protective Devices for Toxic and Irritating Atmospheres Air Transport Flight Deck (Sedentary) Crewmembers

AS8031A (Current)

6/18/2026

This SAE Aerospace Standard (AS) covers any protective system that serves the stated purpose.

A-10 Aircraft Oxygen Equipment Committee

A Comprehensive Review of System Risk in Automotive Crash Safety

15-19-02-0010

6/9/2026

Occupant protection has been at the forefront of risk evaluation regarding vehicle crashworthiness design. However, the vehicle is a member of a larger transportation system with varied stakeholders. This article identifies an opportunity for assessing risk in a crash event through emerging safety science paradigms. Conventional Safety I and Safety II frameworks handle well-defined hazards but falter with uncertainty, variability, and emergent behaviors in real crashes. A comprehensive literature review was performed on peer-reviewed research to situate automotive crash safety risk within the Safety III paradigms. The review addresses two questions: (1) How is “risk” defined across the crash safety literature and adjacent safety science domains? and (2) What limitations arise from these definitions in practice? Findings show a dominant probabilistic framing alongside a minority of system-oriented interpretations. Current crash safety practice lacks a coherent, system-level definition of risk that integrates uncertainty and knowledge strength, leading to fragmented methods and limited alignment with modern safety science. Based on this synthesis, the article proposes guiding principles for Safety III-aligned guidelines and recommendations that integrate consequences, uncertainty, and knowledge strength to improve transparency, traceability, and adaptability in crash safety decision-making.

Rye, Patrick J.

Occupant Sex Equity and Vehicle Safety: Historical Activities, Research, and Countermeasure

2026-22-0002

5/28/2026

Since 2019, sex equity in traffic crashes has been a highly debated topic in vehicle safety, especially following the 2019 study by Forman et al. (1) claiming that female occupants face a 73 percent greater risk of serious injury in frontal crashes compared to male occupants. This was soon followed by a Consumer Reports Article by Keith Barry (2), which attempted to identify underlying factors contributing to the higher risk. These have been embraced by several parties since 2019. Firstly, it was alleged that vehicle design practice over the last four decades considered safety for the male population only and ignored that of the female as evidenced by the exclusive use of the mid-sized male Anthropomorphic Test Devices (ATDs) in Regulatory and Safety Ratings tests and not with an average sized female ATD. The absence of such an ATD for testing of vehicles “set the course for four decades’ worth of car safety design, with deadly consequences” (2). Secondly, although there is a recognition of the fact that Regulatory testing with a Small Female ATD, the Hybrid III-05F, was introduced in the FMVSS208 in 2003, this ATD was only a scaled version of the average male ATD of the 1970’s implying that this ATD is incapable of driving the design of restraint systems for females due to “They’re put together differently. Their material properties—their structure—is different” (2). Thirdly, according to a quote “These same trends have been observed in many, many studies in the past.” We assume that the trends refer to the apparent disparity in safety of females when compared to those of males. This document aims to outline historical activities, associated research and the development of countermeasures addressing crashworthiness concerns related to vehicle safety for females, as well as factors affecting both males and females, such as age-related impacts. This paper deals mainly with the frontal crash modes, mentions side impacts briefly as it affected designs of inflatable restraints for side impact to protect the smaller portion of the population from inflation induced injuries but the history behind the use of female ATDs by IIHS and NHTSA in full scale testing is not covered. Where ever possible, the time periods of reported activities related to female safety have been divided to pre-1997 corresponding to a change in US frontal crash regulation to address serious-to-fatal injuries to females and children, between 1997 to 2003 corresponding to the proposal by Canada for its frontal impact standard, and between 2003 and 2006 when the Advanced Restraint Regulation in the US FMVSS 208 was promulgated. This was followed by activities between 2007 and 2019, and post 2019 period.

Prasad, Priya, Dalmotas, Dainius J.

PMHS Sled Testing of Reclined Small Female Occupants: Pelvic Dynamics and Injury Evaluation

2026-22-0001

5/28/2026

As automated vehicle technologies enable increased seat recline angles during travel, understanding the biomechanics of injury under these novel occupant postures becomes imperative. This study evaluated the pelvis injury response and associated kinematics of reclined small female post-mortem human surrogates (PMHS) subjected to frontal sled tests across three restraint configurations. Each configuration varied in seat stiffness and the presence of a knee bolster to assess their influence on pelvic dynamics and submarining risk. Nine PMHS tests were conducted using a consistent reclined posture (38° thorax, 75–80° pelvis angle) and production restraint systems. Submarining probability was estimated using a validated logistic regression referenced from previous study. Distinct pelvic kinematics, fracture patterns, and associated injury mechanisms emerged across the test configurations in the current dataset. Configuration 1, featuring a stiffer seat without a knee bolster, exhibited complex pelvic fractures—most notably iliac wing fractures resulting from inward bending of the ilium—and a higher probability of submarining primarily due to rearward pelvic rotation. In contrast, Configuration 2, with a compliant seat and no knee bolster, produced comminuted iliac wing fractures, dominated by shear component and a moderate probability of submarining driven primarily by downward pelvic displacement. Configuration 3, which included a knee bolster, showed injury propagation to the posterior pelvis, and none of the subjects submarined. Each configuration included three specimens; therefore, results should be interpreted with caution. Despite the small sample size, the findings highlight the critical influence of seat stiffness and restraint design on pelvic kinematics and injury mechanisms under reclined conditions. The data provided could serve in validating computational models and anthropomorphic test devices (ATDs) in reclined seating configurations.

Somasundaram, Karthik, Driesslein, Klaus, Pintar, Frank A.

Study on Impact Resistance of Sandwich-Structured Battery Protection Panels

2026-99-1728

5/22/2026

With new energy vehicles developing rapidly, battery safety, as an important part of the impact on the range of new energy vehicles and vehicle safety, has become the focus of attention. The battery pack protection plate is a core component to protect the battery, its performance needs not only impact resistance, but also lightweight, honeycomb sandwich structure with its excellent energy absorption characteristics and weight reduction performance by the battery pack protection plate performance research. At present, the core-to-face sheet interaction in conventional sandwich structures subjected to impact loads has not been fully elucidated, and the quantitative characterization of damage is insufficient, so this paper aims to optimize the lightweight impact-resistant structure by exploring the synergistic energy dissipation mechanism between the high-strength core material and the steel plate. The study combines theory and simulation, adopting ideal rigid-plastic film theory to establish a critical response model to predict the structural failure threshold, equivalent single-layer theory to simplify the analysis of plywood, and a stiffness matrix model to quantify the structural mechanical contribution of each layer. A two-material synergistic design framework is proposed by fully considering the material properties and adopting the corresponding intrinsic structure and failure criteria for different materials. Analysis reveals that geometric confinement is a key characteristic of the honeycomb sandwich panel’s response and a strain gradient driving mechanism at low impact resistance, and a new energy distribution paradigm is found through the analysis of the energy absorption ratio. The theoretical and simulation results are in great agreement with each other, which just has a difference of 0.7% in the peak force, 1.4% in the critical displacement error, and less than 2% in the impulse integration error. The proposed dual-material co-design framework provides a solution for electric vehicle battery protection systems that balances lightweight and impact resistance.

Zhang, Guanghao, Zhang, Mingming, Luo, Changjie, Zhou, Jun, Zhang, Fengqiang, Yu, Wenze, Li, Jiongfeng, Guo, Qingrong

Digital Twin Modeling of Electro-Hydraulic Asymmetric Actuator System with Parameters Identified under High-Speed Conditions

2026-99-0747

5/15/2026

The electro-hydraulic asymmetric actuator system is widely used in high-precision fields such as aerospace, robotics, and exoskeletons. As application scenarios evolve toward higher speeds and greater precision, the nonlinear characteristics and multi-physics coupling behavior of these systems become increasingly prominent. The accuracy of their modeling and identification directly impacts the effectiveness of system dynamic performance evaluation, control strategy design, and predictive optimization. Therefore, this paper combines the system structure and transmission characteristics to carry out digital twin modeling and parameter identification research under high-speed conditions. First, a coupling model based on motor-load characteristics and flow characteristics is established; then, the least squares method is proposed to identify the frequency domain Bode response of the motor-controlled pump system and the time domain nonlinear parameters of the hydraulic transmission system; finally, the two models are organically combined to establish a Simulink-AMESim co-simulation model, and the accuracy of the constructed nonlinear model is verified through simulation and experimental comparison. The experimental results show that the speed response error is within 0.5%, and the position tracking error is within 0.5mm. This method can accurately model the electro-hydraulic asymmetric actuator system under high-speed conditions.

Wang, Hao, Zhang, Xin, Ma, Tianbing, Wang, Jian, Zhang, Tao, Wang, Lei, Shi, Yongping, Wang, Chao

Research on the Friction Performance of EVA Insulating Mats for Live Working in Smart Grids

2026-99-0714

5/15/2026

Live-line operation is a critical technique for maintaining the reliability and continuity of power supply in modern distribution networks. Insulating mats serve as essential protective equipment during such operations by providing both electrical insulation and mechanical shielding. In practical service conditions, insulating mats are subjected to repeated mechanical contact and friction against conductors, metallic fittings, and ground surfaces, which progressively deteriorates their surface integrity and compromises operational safety. Current performance standards for insulating mats emphasize dielectric and tensile properties, while tribological durability remains unaddressed. In this study, an EVA – PA6 composite film fabricated via the tape casting method was selected as the representative outer insulating layer of insulating mats. Reciprocating friction tests were conducted using an SDR339 abrasion tester to evaluate the effects of normal load and sliding speed on wear behavior. The results indicate that wear mass increased monotonically with friction cycles at a given speed, whereas the incremental wear rate gradually decreased due to contact area evolution. A pronounced transition from mild surface abrasion to severe material removal was observed when the applied load reached 5 N, accompanied by surface scratching and exposure of the internal fibrous layer. These findings demonstrate that the wear resistance of the EVA – PA6 composite film is insufficient for long-term service under realistic frictional conditions. The results provide experimental evidence supporting the necessity of incorporating standardized wear resistance evaluation into performance criteria for insulating mats used in live-line operations.

Sun, Xin, Wen, Libin, Kou, Hanpeng

An Integrated Workflow for Structural Dynamics, Comfort, and Airbag Deployment for Virtual Seat Design

F-0082-2026-0329

5/5/2026

This paper presents an integrated simulation workflow for aircraft seat development that combines (i) structural dynamics and certification load cases, (ii) occupant comfort and living-space assessment using finite-element digital humans, and (iii) airbag folding, deployment, and calibration using a coupled gas-dynamics solver suited to early-time transients. The workflow is built around a single manufacturing-aware, as-built seat model that is reused across comfort, certification, and restraint-system studies, allowing design iterations to move upstream before design freeze. Each stage is paired with validation or industrial case examples, and the airbag-calibration process is accelerated through reduced-order modeling (ROM) of parameter identification. The result is a practical virtual-seat-development methodology that is sufficiently predictive to de-risk physical testing while remaining fast enough for concept iteration and late-stage compliance support.

Dwarampudi, Ramesh, Vaz, Ignatius

Assessing the Influence of Reclined Vehicle Seatback Configurations with and without a Belt-Positioning Booster on Child Posture via Pressure Mapping

09-14-01-0004

5/4/2026

Objective: This study sought to implement pressure mapping methodology to assess variation in children’s center of force positions in reclined vehicle scenarios. Methods: Thirty-four children between 4 and 12 y (8.1 ± 2.0 y) were statically evaluated on a vehicle seat across two seating conditions (with and without a backless booster) and three seatback recline conditions (25°, 45°, and 60°). Center of force was recorded using pressure sensors attached to the seating surface. Average center of force fore/aft positions were calculated and transformed into the vehicle coordinate system using 3D coordinate measurements. Descriptive statistics and repeated measures ANOVA were used to assess variation in center of force position across seating and recline conditions, with subject included as a random effect. Results: Center of force fore/aft position varied (p < 0.05) with recline condition, seating condition, and the recline/seating condition interaction term. On the booster, the average center of force position became more aft in the 45° (131.1 ± 17.5 mm) and 60° (125.5 ± 16.7 mm) conditions compared to 25° (148.7 ± 17.4 mm). Without the booster, the center of force also became more aft in the 45° (197.7 ± 31.1 mm) condition compared to the 25° condition (204.6 ± 29.1 mm), but the position in the 60° (206.1 ± 31.8 mm) condition was similar. As children assumed more reclined postures, the center of force became more aft, except for the no-booster 60° condition. Discussion: Changes in center of force followed the same trends observed in the pelvis and lower extremity position (became more aft) with increasing seatback recline on the booster and smaller changes observed on the no-booster condition. Future work should investigate additional vehicle/booster geometries and longer seating durations. The changes in center of force observed with seatback recline emphasize the importance of understanding how real children modify their posture over time to different vehicle environments as posture directly influences belt fit, occupant–restraint interaction, and injury risk. Center of force data can inform the positioning of child surrogates in future dynamic evaluations of reclined configurations.

Baker, Gretchen H., Connell, Rosalie R., Graci, Valentina, Mansfield, Julie A.

Characterization of Pedestrian Automatic Emergency Braking Acceleration in Modern Light Vehicles: Potential Implications for Occupant Safety

09-14-01-0007

5/4/2026

The objective of this study was to characterize and compare pedestrian automatic emergency braking (PAEB) pulses in modern light vehicles to understand the loading environment that vehicle occupants are being exposed to during PAEB maneuvers. PAEB tests (n = 8008) conducted using 2018–2023 vehicle model years were analyzed. Pulse, vehicle, and impact characteristics (e.g., jerk, peak acceleration, pedestrian scenario, etc.) were derived from each PAEB test. Two k-means clustering analyses were used to group PAEB pulses with and without target collisions based on their similarity between characteristics. One-way ANOVA and Kruskal–Wallis tests were performed on the PAEB pulse characteristics to examine differences between clusters (p < 0.05). Two non-collision clusters (NC1 and NC2) were identified for PAEB pulses without collisions: NC1 had a statistically significant lower jerk (0.8 ± 0.4 g/s) and peak acceleration (1.0 ± 0.1 g) compared to NC2 (1.6 ± 0.8 g/s and 0.9 ± 0.1 g, respectively, p < 0.001). NC1 was mostly represented by stationary adult (88.6%), 60 km/h (99.5%), and 40 km/h (62.2%) tests. NC2 was mostly represented by crossing scenarios (child: 92.3%; adult: 70.5%) and 20 km/h (96.2%) tests. Three collision clusters (C1, C2, and C3) were identified for PAEB pulses with collisions. C3 showed a greater jerk (1.5 ± 0.8 g/s) compared to C1 (0.9 ± 0.6 g/s) and C2 (1.1 ± 0.9 g/s, p < 0.001). These results suggest that with successful avoidance, deceleration begins earlier with higher speeds and a stationary pedestrian, resulting in potentially milder loading conditions for vehicle occupants (i.e., lower jerk in NC1 vs NC2). With unsuccessful avoidance, in daytime pedestrian crossing scenarios, lower impact speeds were observed, resulting in potentially non-optimal loading conditions (i.e., higher jerk and peak acceleration in C3) for vehicle occupants. At night with low beams, C2 may result in advantageous loading conditions for vehicle occupants (i.e., lower jerk and peak acceleration), but it may lead to the worst outcome for pedestrians (i.e., greatest impact speed).

Witmer, Maitland, Kidd, David, Graci, Valentina

Interactions of Rear-Facing Child Restraints in Frontal Crash Tests

09-14-01-0010

5/4/2026

The aims of this study were to investigate the kinematics of child anthropomorphic test devices in a large sample of rear-facing child restraint system installations and the effects of anti-rebound features and load legs on the kinematics of rear-facing child anthropomorphic test devices. The test matrix included a general sample of 70 rear-facing child restraint system installations to observe trends in frontal crash tests; 14 full-scale crash tests with paired comparisons to investigate the effect of anti-rebound features; and five paired comparisons of rear-facing child restraint systems installed with and without a load leg. The paired t-test was used to determine the statistical significance of differences in kinematic responses. In the general sample, 84% of anthropomorphic test devices in infant seats with the base in outboard seats interacted with the first-row seat. In 52% of tests, the anthropomorphic test device head directly contacted the front seatback. Head accelerations > 80 g were caused by interactions between: the child restraint system and front seatback; the anthropomorphic test device head and the interior surface of the child restraint system; or the anthropomorphic test device head and front seatback. In the anti-rebound sample, head contact on rebound occurred in three infant seat installations, and all were associated with head resultant accelerations ≤33 g. The mean paired difference in head 3 ms clip was negligible (p > 0.05). In the load leg sample, the load leg limited forward excursion and forward rotation of the rear-facing child restraint system, thereby contributing to the containment of the anthropomorphic test device within the boundary of the child restraint system shell. In this study, anti-rebound features did not improve the kinematics of pediatric anthropomorphic test devices. The feasibility of including the use of the load leg in the Canadian regulatory test protocol should be explored.

Tylko, Suzanne, Tang, Kathy

The Effect of Initial Foot Position on THOR-50M and THOR-05F Lower Leg Response in a Realistic Vehicle Buck

09-14-01-0008

5/4/2026

This study aims to explore and evaluate the effect of various foot positions on the kinematic and kinetic response of the lower extremity during frontal crashes using a realistic vehicle interior. Frontal impact sled tests were performed with the Test Device for Human Occupant Restraint, 50th-percentile Male (THOR-50M) and Test Device for Human Occupant Restraint, 5th-percentile Female (THOR-05F) anthropometric test device (ATD) in the driver’s seat of a midsize SUV testing buck (with realistic interior components including an instrument panel with steering wheel and steering wheel airbag, seat, three-point seat belt with pretensioner and force-limiter, accelerator pedal, brake pedal, knee airbag, and seat belt retractor pretensioner). Six sled tests were performed in two principal directions of force (PDOF) [three each in frontal (0°) and oblique (−20°) configurations]. The right foot was positioned on the accelerator pedal, fully on the brake, and half on the brake. A single test was conducted with the THOR-05F in an oblique configuration with the foot on the accelerator. Ankle response was analyzed from internal ATD instrumentation. Restraint engagement was found to be consistent across all testing cases. Ankle moment and angle varied based on PDOF and the tested foot condition. Right ankle moment ranged from 70 to −70 Nm in inversion/eversion. Right ankle angles ranged from 37° inversion to 28° eversion. Left ankle moment ranged from 10 to −41 Nm in inversion/eversion. Left ankle angles ranged from 10° eversion to 23° inversion. Differences in lower extremity motion and loading were observed for each testing condition. Placing the foot on the accelerator pedal produced greater ankle moment than either brake pedal condition. Placing the foot on the brake pedal resulted in the highest dorsiflexion angle response. Obliquity increased ankle moment and rotation for both ankles. The United States New Car Assessment Program (US-NCAP) foot position with an oblique PDOF created the highest ankle moment while the in-line brake position in oblique created the highest dorsiflexion rotation. By combining these findings with other efforts focused on naturalistic driving and foot positioning, these results might aid in development of additional testing practices that might enhance our understanding of the lower extremity in nonstandard initial positions.

Noss, Junior, Donlon, John-Paul, Morris, Anna, Samier, Germain, Park, Joseph, Forman, Jason

Front-Row Seatback Contact for Pediatric Occupants Seated in Rearward-Facing Infant Child Restraint Systems during Frontal Crashes

09-14-01-0019

5/4/2026

Using a subset of the Transport Canada dataset of rearward-facing CRS in full-frontal rigid barrier vehicle tests, the aim of the current study was to evaluate CRS and/or ATD head contact with the front-row seatback and categorize the contribution to the peak ATD head acceleration. For 33 cases of ATDs seated in rearward-facing CRS models installed in the second-row outboard seats across 19 vehicle tests, high-speed video footage was analyzed to identify instances and timings of CRS and/or ATD head contact with the front-row seatback. The timing of contact was compared to the ATD head acceleration time history to identify instances of “contributory contact” with the front-row seatback, which was defined as contact occurring before the ATD head acceleration was within 10 g of the peak. ATD contributory contact cases involved both the ATD head and CRS contacting the front-row seat, whereas CRS contributory contact cases involved only the CRS, but not the ATD head, contacting the front-row seat. No contributory contact cases were those that involved either ATD or CRS contact with the front-row seatback, but the contact occurred after the time point associated with 10 g below the peak ATD head acceleration. No contact cases were those that did not involve either ATD or CRS contact with the front-row seatback. Contributory CRS and/or ATD contact with the front-row seatback was found to be associated with increased head injury risk. Therefore, the energy-absorbing properties of the CRS head restraint and/or front-row seatback are likely important considerations regarding frontal crash protection for rearward-facing pediatric second-row occupants. Impact velocity, location, and angle were able to be calculated for two cases that involved contributory ATD contact with the front-row seatback. Such data could be used as boundary conditions for physical testing of front-row seatbacks and computational modeling.

Patton, Declan A., Tang, Kathy, Tylko, Suzanne, Arbogast, Kristy B.

Comparative Analysis of Thoracic Injury and Causative Factors across Sexes in Serious Frontal Motor Vehicle Collisions in the Crash Injury Research and Engineering Network Database

09-14-01-0031

5/4/2026

This study investigated sex-specific differences in thoracic injury prevalence, causation, and rib fracture patterns among seriously injured occupants in frontal motor vehicle collisions. Crash Injury Research and Engineering Network (CIREN) data from 2005 to 2022 included 793 front-seat occupants aged 16 years and older with Abbreviated Injury Scale 2+ thorax injury, representing 1802 thoracic injuries. Injuries were grouped as rib fracture, sternum fracture, hemo/pneumothorax, lung injury, heart injury, and other. A weighted scoring system captured contributions of involved physical components to each injury. Logistic and linear regression with generalized estimating equations assessed sex associations with injury presence and causation. Two models were estimated: a comprehensively adjusted model including demographic, crash, vehicle, restraint, and airbag deployment, and a simplified model adjusting for age, body mass index, delta-V, and occupant role. Among occupants with AIS 2+ thoracic injuries, sex-specific differences were observed in injury patterns and causation. Females were less likely than males to sustain lung injuries (OR = 0.70, p = 0.038) and more likely to sustain rib fractures (OR = 1.25, p = 0.006). Females had higher odds of rib fractures attributed to seatbelt loading in both models (Full: OR = 2.20, p = 0.005; Simplified: OR = 1.55, p = 0.021). Females were less likely than males to sustain lung injuries (OR = 0.17, p = 0.042) and hemo/pneumothoraces (OR = 0.15, p = 0.044) from instrument panel loading. Steering wheel, airbag, and other components showed no significant sex-specific associations with thoracic injury. Rib fracture patterns showed clusters along the seatbelt path in belted occupants and a more diffuse pattern in unbelted occupants, with minimal significant findings of differences between sexes. These findings contribute to the growing evidence of sex-specific injury patterns and may inform future research on injury prediction and prevention strategies. However, this dataset includes only occupants with AIS 2+ thoracic injuries and therefore cannot be extrapolated to the general population or to collisions outside those represented in the sample.

Armstrong, William, Devane, Karan, Hsu, Fang-Chi, Heilmann, Nina, Sink, Joel, Miller, Anna N., Kiani, Bahram, Martin, R. Shayn, Stitzel, Joel D., Weaver, Ashley

Injury and Kinematics of Obese PMHS in Frontal Impacts with Reclined Seating

09-14-01-0003

5/4/2026

Objective: This study investigated injury outcomes and body kinematics in obese occupants exposed to frontal impacts while seated in reclined postures. With increasing interest in non-traditional seating configurations and a growing population of obese vehicle occupants, the objective was to evaluate how seat stiffness and restraint features influence injury patterns and whole-body excursions. Methods: Nine obese post-mortem human surrogates (PMHS; mean age: 64 years, stature: 1.70 m, body mass: 102 kg, BMI: 35 kg/m2) were tested under frontal impact conditions simulating a delta-V of 50 kph. All specimens were seated on a spring-controlled seat with a 45° reclined seatback and restrained by a three-point belt system with pretensioner and load limiter. Three configurations were evaluated: (1) stiffer seat, (2) softer seat, and (3) stiffer seat with a knee bolster 100 mm from the knees. Each subject underwent one test. Whole-body kinematics were captured using a VICON motion analysis system, and injury outcomes were assessed through radiographs, CT imaging, and autopsy, with severity classified by Maximum Abbreviated Injury Scale (MAIS) and Injury Severity Score (ISS). Results: Softer seats produced substantially greater downward (+Z) pelvic displacement compared with stiffer seats. The knee bolster effectively reduced both downward and forward excursions of the lower torso. Rib cage and pelvic injuries were most frequent, with the highest severity observed in softer seat tests. Mean ISS values were: STIFF—27, 13, 27; SOFT—34, 27, 14; STIFF-KB—22, 0, 13. Discussion: Reduced seat stiffness combined with increased occupant mass contributed to greater excursions and anterior torso injuries, whereas the knee bolster mitigated excursion and injury severity. Findings are limited by sample size and test conditions; broader evaluation with production seats is needed to confirm trends and support countermeasure design.

Somasundaram, Karthik, Yoganandan, Narayan, Pintar, Frank

Neck and Spinal Responses in the Reclined Large Omnidirectional Child Anthropomorphic Test Device with and without a Booster Seat during Far-Side Lateral Oblique Impacts

09-14-01-0011

5/4/2026

Objective The objective of this study was to examine the Large Omnidirectional Child (LODC) anthropomorphic test device (ATD) neck and spine responses in reclined seating configurations with and without a backless belt-positioning booster (BPB) in far-side lateral oblique impacts. Methods The LODC was seated on a production passenger seat with an integrated seatbelt and tested in nine lateral oblique impact (80° from frontal) sled tests (31.3 km/h). A condition with a nominal seatback angle (~25°) with a backless BPB and two conditions with reclined seatback angles (~45° and ~60°) with and without a BPB were compared. Each condition was repeated, except for the 60° without BPB. Peak upper neck tension force and lateral moment, T1, T6, and T12 lateral rotation, lumbar axial and lateral shear forces, and lumbar axial moment (Mz) were extracted. Results With noBPB, upper neck tension (45° noBPB: 2.0 ± 0.1 kN; 60° noBPB: 1.8 kN) and lateral moment (45° noBPB: 31.7 ± 2.3 Nm; 60° noBPB: 29.2 Nm) were greater than with the BPB in all seatback angles (25° BPB: 1.3 ± 0.04 kN; 21.6 ± 0.1 Nm; 45° BPB: 1.2 ± 0.1 kN, 22.5 ± 2.3 Nm; 60° BPB: 1.2 ± 0.03 kN, 17.6 ± 0.7 Nm). Thoracic spine rotation was smaller in reclined conditions with noBPB (41°–59°) than with BPB (63°–80°). Lumbar axial forces decreased with increasing seatback angle with the BPB (from 2.2 to 1.2 kN). Lumbar Mz showed increasing unbelted shoulder rotation toward the seatback with increasing seatback angle (from 29.8 to 37.8 Nm) with the BPB but not without. Discussion The presence of the BPB may improve neck and spine coupled motion during far-side lateral impacts. However, increased lumbar Mz with the BPB in recline seatbacks requires further understanding.

Graci, Valentina, Humm, John, Hauschild, Hans

Resilient Nylon Device Creates Electricity Under Tons of Pressure

TBMG-55064

5/1/2026

Certain materials — such as quartz, some ceramics, and even bone — produce an electrical charge when they are squeezed, pressed, or vibrated. This is piezoelectricity, which comes from the Greek “piezein” meaning to press. Modern vehicles rely on piezo components in fuel injectors, parking sensors, airbag systems, and other functions.

MEMS in Transition

TBMG-55068

5/1/2026

Wide-scale applications for Micro-Electromechanical Systems (MEMS) became practical in the 1980s when they started being fabricated with the same silicon wafer processes as semiconductor chips. Once they could be mass produced, they found a major market in automobile safety systems as inertial sensors for airbag deployment. Then came the introduction of smart phones in the late 2000s. According to Dr. Alissa M. Fitzgerald, CEO, A.M. Fitzgerald & Associates, a MEMS and microtechnology product development company, every smart phone these days contains dozens of MEMS chips. And now there are many more safety applications in automobiles beyond just air bag sensing.

Securing Child Restraint Systems in Motor Vehicles

J1819_202604 (Current)

4/13/2026

The scope of this SAE Recommended Practice is to promote compatibility between child restraint systems and vehicle seats and seat belts. Design guidelines are provided to vehicle manufacturers for certain characteristics of seats and seat belts and to child restraint system (CRS) manufacturers for corresponding CRS features so that each can be made more compatible with the other. The CRS accommodation fixture (see Figure 1) is used to represent a CRS to the designers of both the vehicle interior and the CRS for evaluation of each product for compatibility with the other. The features of the accommodation fixture are described as each is used.

Children's Restraint Systems Committee

Potential Regulatory Approaches for Occupant Safety in Automated Vehicles with Unique Seating Configurations – Part 1: Occupant Protection Proposals

2026-01-0578

4/7/2026

Some Automated / Autonomous Vehicles (AVs) have unique seating configurations (stagecoach and campfire seating) which present expanded occupant safety challenges. Significant portions of the National Highway Traffic Safety Administration (NHTSA) Federal Motor Vehicle Safety Standards (FMVSS) do not yet align with AVs containing unique seating. This paper series takes the NHTSA occupant safety standard approach for conventional forward-facing seat vehicles where many compliance evaluations are in the frequently occupied front row and expands it to stagecoach and campfire AVs where the rear seating row is anticipated to be frequently occupied. The approaches proposed are from a logic-based safety-focused analysis and in many cases previously published material. The goal of this paper series is to offer regulatory proposals that enable equivalent performance for these AVs to existing forward-facing seating vehicle occupant safety standards and meet Executive Order 13045 on child safety. Part 1 (this paper) focuses on occupant protection for the front and rear seating rows in stagecoach and campfire seating AVs for: front impacts (FMVSS-208), windshield mounting (FMVSS-212), windshield glazing (FMVSS-219), rear impacts (FMVSS-301/305), head restraints (FMVSS-202a), head impacts (FMVSS-201), side impacts (FMVSS-214), roof crush (FMVSS-216a), ejection mitigation (FMVSS-226), and door pinch (a potential FMVSS-118 addition). Some of the proposals address occupant performance for vehicles without traditional leg and restraint reaction surfaces. In addition, an interior safety sensing approach that assesses if occupants are properly restrained before a ride can begin is proposed as an alternative / a replacement for unbelted in-position occupant performance compliance evaluations. This document also provides regulatory condition thoughts for AVs without a usable driver seat location. Part 2 (SAE paper 2026-01-0576) discusses interior safety sensing and associated messaging. These approaches can be used in industry-wide regulatory next step contemplation and deliberation for unique interior seating arrangement AVs, including public discussions, safety research, approach proposal development, and rulemaking efforts.

Thomas, Scott

Application of DFSS for Optimizing Thermal Protection in Electric Vehicles during Battery Thermal Runaway Events

2026-01-0142

4/7/2026

Battery thermal runaway is a major safety concern in electric vehicles because of the extreme heat and hazardous gases released during cell failure. These venting events can quickly raise the temperature of the battery enclosure and cabin floor, threatening occupant safety. To address this challenge, this study employs the Design for Six Sigma (DFSS) methodology to design and optimize a thermal protection system that delays and limits heat transfer to the cabin. A physics-based transient heat-transfer model was combined with DFSS principles to systematically evaluate insulation materials, shield layouts, surface emissivity, and layer geometry. An L-18 orthogonal array was used to identify key parameters and quantify their influence on thermal robustness. The optimized architecture reduced cabin-floor temperature rise under severe runaway conditions (600–900 °C vent gas), meeting occupant-egress safety requirements. Findings confirm DFSS as an effective framework for developing high-robustness EV thermal protection systems under uncertainty and extreme boundary conditions.

El-Sharkawy, Alaa, Asar, Mona, Taha, Nahla, Sheta, Mai

Evaluating the Effects of Improper Positioning and Unbuckling of a Restraint System on a 10-Year-Old Child ATD in a Far Side Side-Impact Environment

2026-01-0562

4/7/2026

Five sled tests were performed with a Hybrid III (H-III) 10-year-old child sized Anthropomorphic Test Device (ATD) positioned in the 2nd row left seat of a three row 2006 Sport Utility Vehicle (SUV). A HYGE Sled buck was positioned to represent/replicate a side impact collision to the passenger (right) side of the SUV, with a Principal Direction of Force (PDOF) of 60 degrees, resulting in a far side side-impact for the ATD. Of the 5 tests performed, three of the five tests were performed with a delta-V of 17 mph, and two of the tests at a delta-V of 24 mph. Of the 17 mph tests, one test was performed with a properly restrained ATD, and two tests performed with improper restraint positioning. Both of the 24 mph tests were performed with improper restraint positioning, effectively identical to the two 17 mph delta-V tests. The two improper restraint use tests (at both 17 and 24 mph delta-V) included two different improper restraint scenarios. The first scenario of improper restraint positioning involved moving the torso belt from the left shoulder, over the head, and onto the right shoulder. The second scenario involved the same belt re-positioning as the first scenario, but additionally a disengaged latch plate from the buckle, essentially creating a condition of seat belt entanglement. Each of the five tests utilized its own salvage-vehicle-harvested seat belt assembly, originating from the same model series of SUV. All tests were documented with 4 high-speed video cameras. Occupant kinematics and seat belt physical evidence were analyzed and compared across the test series. Head accelerations and upper neck loads were also evaluated. The results demonstrated the uniqueness of physical evidence left behind on components of the seat belt system, both in terms of locations of the evidence as well as the extent and geometric orientation of the evidence, across the three demonstrated scenarios (proper, improper, and improper and unbuckled). Additionally, the three scenarios exhibited significant differences with respect to the head accelerations and neck loads experienced by the ATD.

Luepke, Peter, Hewett, Natalie, Betts, Kevin, Van Arsdell, William, Weber, Paul, Stankewich, Charles, Miller, Gregory, Watson, Richard, Sochor, Mark

Effects of Child Anthropometry, Seatback Angle, Seat Rotation Angle, Seatbelt Force Limiting, and Collision Type on Injury Risk of Child Occupants in Highly Automated Vehicles

2026-01-0570

4/7/2026

This study aimed to evaluate the influence of child anthropometry, seating postures (recline and rotation), seatbelt force limiting, and frontal collision scenarios on the kinematic response and injury risk in highly automated vehicles. The TUST IBMs 6YO-O model was conducted the frontal collisions in sled tests. This simulation matrix includes five percentiles six-year-old occupants (P3, P25, P50, P75, and P97), three seatback angles (20°, 30°, and 45°), four seat rotation angles (0°, 90°, 180°, and 270°), three seatbelt force limiting (2.6 kN, 3.6 kN, and 4.6 kN), and three frontal collision types. Injury risks were assessed including the child occupant's head, neck, chest/abdomen, and lumbar region in each simulation (n=540). The results indicate that the child anthropometry, the seatback angle, and the seat rotation angle have a significant influence on the motion responses. Statistically significant differences between all the groups within each independent variable category were observed based on the analysis of variance. As the child dimension increases, the risk of head injury decreases showing by HIC15, while the risk of neck and lumbar injuries increases. As the seatback angle increases, biomechanical parameters of the head show an increasing trend. The risk of upper neck injury decreases, while the risk of lumbar injury decreases and then increases. As the seat rotation angle increases, the risks of head, neck, and chest injuries initially rise and subsequently decrease, while the risk of lumbar injury demonstrates a downward trend. Seatbelt force limiting exhibited a positive correlation with head, neck, and lumbar injury risks. Consequently, small percentile child experiences higher head loads in smart cockpits, with seatback angle and seat rotation angle being key factors contributing to child injuries. These findings highlight the critical need to address the vulnerability of smaller children in smart cockpits by adapting integrated active and passive safety systems to mitigate their injury risk.

Wang, Yanxin, Zhao, Hongqian, Li, Haiyan, He, Lijuan, Cui, Shihai, Lv, Wenle

A Study on the Injury Risk of Occupant with Different Head and Neck Rotating Postures under the Frontal Impact Sled Conditions

2026-01-0574

4/7/2026

Drivers obtain road information through head and neck rotation. In order to study the influences of head and neck rotation posture on occupant injury in frontal impact scenario, the THUMS (Total Human Model for Safety) AM50 human body model with five different head and neck rotation postures but without active muscles was adopted to study the biomechanical injury responses of occupant under the frontal impact scenario at 56 km/h in this study. Firstly, the kinematic responses of total body and head acceleration curves at the center of gravity predicted by PMHS (Post Mortem Human Subject) and THUMS AM50 human model under the sled test conditions were compared to verify the simulation model for subsequent study. Then, the THUMS AM50 human model with standard occupant seating posture was adjusted to have five different head and neck rotation postures with 0°, ±20°, and ±40° rotation angle, respectively. Finally, a series of frontal impact sled with or without airbag simulations were conducted for each THUMS AM50 human model with different head and neck rotation postures. The simulation results showed that with the increasing of head and neck rotation angle, the neck injury risk was increased while the thoracic injury risk was decreased. Regardless of whether airbags were present or absent, the model prediction for the standard posture indicated a lower injury risk. And regardless of whether the head and neck posture changed, the airbag always could provide a certain protection in that posture.

Li, Dongqiang, jiang, Yejie, Tan, Chun, Li, Yanyan, Gong, Chuangye, Wu, Hequan, Jiang, Binhui

Machine Learning Based Meta-Analysis of IIHS Moderate Overlap Frontal Crash Test for Rear Seat Occupant Safety Performance

2026-01-0579

4/7/2026

A machine learning (ML)-based meta-analysis was conducted to evaluate rear seat occupant safety performance in the Insurance Institute for Highway Safety (IIHS) Moderate Overlap Frontal (MOF) 2.0 crash test. ML models were trained on historical IIHS crash test data to predict rear passenger injury metrics using vehicle architecture, restraint system characteristics, crash pulse parameters, and vehicle kinematics as input features. The models demonstrated high predictive accuracy and were subsequently used in a Sobol sensitivity analysis to identify critical design parameters influencing injury outcomes. The analysis revealed that rear passenger injury metrics were most sensitive to restraint system parameters. Specifically, crash pulse magnitude was the dominant factor for head injury metrics, pretensioner activation time for neck tension force, and lap belt force for the Neck Injury Criterion (Nij). For chest-related metrics—sternum deflection, dynamic belt position, and maximum belt position—the initial belt position emerged as the most influential factor. This study demonstrates the potential of ML models to uncover dominant injury mechanisms and critical design parameters without explicitly encoding biomechanical knowledge. The findings also offer actionable insights to guide future vehicle safety design improvements for rear seat occupants.

Lalwala, Mitesh, Kim, Wonhee, Furton, Lisa, Song, Jay

Occupant and Seat Responses in Various Moderate- to High-Speed Rear Impact Conditions: Focus on Head-to-Head Restraint Interactions

2026-01-0565

4/7/2026

Head restraint requirements and designs have evolved to minimize the delay in head support and reduce differential loading in the neck. As a result, they have become bigger, closer to the occupant’s head, and angled forward relative to the seat back. Head restraints have been found missing or detached in the field; they may be removed pre-crash due to occupant comfort issues, or post-crash for better accessibility during extrication. Additionally, although rare, head restraints may become detached in severe rear impacts due to occupant loading. To better understand occupant-to-head restraint dynamic interactions, nine rear sled tests were conducted. The test conditions were selected to represent worst case severe loading scenarios. An instrumented 50th Hybrid III ATD (Anthropomorphic Test Device) was lap-shoulder belted on a right-front seat. The neck was equipped with a bracket and lower neck load cell designed for rear impacts. Three series of sled tests were performed wherein the kinematics and kinetics of a restrained ATD were compared across 3 seat configurations: a conventional modern seat, a rigidized modern seat, and an ABTS (all-belts-to seat). Occupant postures evaluated included seated nominally and leaning forward, as may occur in response to hard pre-impact braking and/or an initial frontal impact. Two crash severities were evaluated including a moderate speed (24 km/h delta V pulse based on Euro NCAP) and a very high-speed (49 km/h delta V) condition. Within each series, the sled pulse and ATD initial posture were held constant. The first series (Match #1) was conducted at 24 km/h with a leaned occupant. All biomechanical responses were below IARVs (Injury Assessment Reference Values). The highest responses relative to IARV were for upper and lower neck tension and extension. The Nij was greatest with the ABTS seat for upper neck and with the rigidized seat for lower neck, highlighting the importance of using both the upper neck and lower neck instrumentation. The second series (Match #2) was at 49 km/h with the nominally seated ATD, and the third (Match #3) was at 49 km/h with a leaning forward ATD. The biomechanical responses were below IARV when nominally seated. The biomechanical responses of Match #2 were more favourable than Match #3, highlighting the benefits of early energy absorption during the ride-down. For example, the upper neck Nij was 2.4 in the conventional seat, 4.2 in the rigidized seat and 5.1 in the ABTS. The corresponding lower neck Nij was 4.2, 5.5 and 2.3. The normalized chest 3 ms response was greatest in the rigidized seat, followed by the ABTS, irrespective of sitting posture. There are numerous reasons for an occupant to be out of position prior to a rear impact. In this study, the test conditions were selected to assess head-to-head restraint interactions in severe conditions, including leaning forward. Though the head restraints remained attached in all tests, the results provide insight on the seat and head restraint performance, and head and shoulder loading characteristics, in particular in some non-nominal postures.

Parenteau, Chantal, Burnett, Roger, Davidson, Russell

Injury Risk Analysis of Occupant with Different Lower Limb Postures under the Frontal Impact Sled Conditions

2026-01-0572

4/7/2026

To investigate the characteristics of injuries sustained by occupant with different lower limb postures under the frontal impact sled conditions. Using the finite element method a series of simulation analyses were conducted on THUMS (Total Human Model for Safety) AM50 human body model with four different postures, including standing posture, lower limb bent at 100°, 90°, and crossed forward-backward, under the frontal impact scenario at 56 km/h in this study. The simulation results indicated that the overall injury risk predicted by the THUMS AM50 huma body model with lower limb crossed forward-backward was higher than that predicted by the model with other postures. The values of injury criteria including of HIC (Head Injury Criterion), head resultant acceleration, and thoracic VC (Viscous Criterion) predicted by the THUMS AM50 huma body model with lower limb crossed forward-backward were highest in these series simulations. Also, the biomechanical responses, including stress or strain of thoracic/abdominal organs, pelvic cortical bone and knee ligaments, predicted by the THUMS AM50 huma body model with lower limb crossed forward-backward was higher than these predicted by the model with other postures.

Li, Dongqiang, jiang, Yejie, Tan, Chun, Li, Yanyan, Li, Yihui, Wu, Hequan, Jiang, Binhui, Zhu, Feng

Potential Regulatory Approaches for Occupant Safety in Automated Vehicles with Unique Seating Configurations – Part 2: Interior Safety Sensing and Messaging Proposals

2026-01-0576

4/7/2026

This paper contains Part 2 of a two-part paper series proposing potential regulatory approaches for occupant safety in Automated / Autonomous Vehicles (AVs) with unique seating configurations (stagecoach and campfire seating). Part 2 focuses on interior safety sensing, associated messaging, and ride control approaches both prior to and during a ride. Assessments are also proposed after significant vehicle braking and crash events. The proposed conditions are to be assessed in a static vehicle environment with humans segmented by occupant size and an infant dummy. On the vehicle seat and on the vehicle floor occupant detection conditions are proposed along with restraint usage detection conditions for vehicle seat belt usage, Child Restraint Seat (CRS) usage, CRS seat belt usage, and Lower Anchors and Tethers for Children (LATCH) system usage. These conditions may be detected by sensors / computer algorithms and human monitoring and thus are technology agnostic. The topics of animal detection and cargo detection are also discussed. Part 1 of this paper series (SAE paper 2026-01-0578) proposed using interior safety sensing as an alternative / a replacement for the National Highway Traffic Safety Administration (NHTSA) Federal Motor Vehicle Safety Standard 208 (FMVSS-208) Occupant Crash Protection unbelted in-position occupant compliance conditions. This paper proposes conditions involving occupant and seat belt restraint usage detection. This evaluation approach strives to prevent unbelted occupants and is an improvement over restraint countermeasures for unbelted occupants. This paper also discusses and proposes visual and audible safety messaging for prior to the ride occupant education and for occupant and restraint usage detection outcomes. Vehicle level ride control actions are suggested such as preventing a ride when improperly restrained occupants are detected. These approaches can be used in industry-wide regulatory next step contemplation for unique interior seating arrangement AVs. When adopted, these approaches would likely reside in an expanded version of FMVSS-208.

Thomas, Scott

HaloBus: Edge Computing-Enabled Real-Time Boarding and Exit Detection for Enhanced Transportation Safety Using Lightweight AI

2026-01-0555

4/7/2026

This paper proposes HaloBus, an innovative, edge-computing solution designed to mitigate this risk by detecting student boarding and exiting in real time using lightweight AI based methods. A persistent challenge in elementary school transportation is the issue of missing students after they exit their buses, which disproportionately impacts low-income households. Current safety systems place the burden of implementation on individual households, often requiring independent methods. Common methods include applications on a personal device or a small tracker. However, not everyone can afford these options, and ensuring child safety is a primary concern for parents and caregivers. That is why HaloBus was invented. The system employs YOLOv5us—an Ultralytics-enhanced, anchor-free, split-head architecture that offers a superior accuracy speed trade-off. By providing real-time, on-device alerts, HaloBus enables immediate intervention to prevent a student from being left behind, thereby shifting the focus from reactive post-incident response to proactive safety. Trained on over 70,000 labeled and unlabeled images, the model can accurately detect multiple students simultaneously, significantly reducing false positives. In real-world deployment, the model sustained 30 frames per second on the Raspberry Pi and achieved detection confidence levels exceeding 75% even when subjects wore sunglasses or hoodies. With opt-in participation for each family, HaloBus effectively balances detection efficiency and privacy protection. Overall, HaloBus offers a low-cost, scalable, and ethically conscious approach to enhancing school-bus safety by delivering reliable, on-device boarding and exit detection for multiple students in varied real-world conditions.

Getz, Grayson, Zadeh, Mehrdad, Tan, Teik-Khoon

Guidelines for Interior Material Selection to Enhance Thermal Safety in Electric Vehicles

2026-01-0249

4/7/2026

The advancement of electric vehicles necessitates a rigorous focus on passenger cabin safety, particularly concerning the severe thermal hazard of a lithium-ion battery thermal runaway. Unlike internal combustion engine vehicles, electric vehicles require interior materials that provide superior thermal resistance to slow heat propagation, delay autoignition, and minimize smoke and toxic gas emissions, thereby securing a survivable evacuation window. This paper examines the application of the lumped-capacitance thermal model and the derived thermal time constant (τ) as a foundational framework for evaluating and selecting cabin materials. This approach enables a quantitative, physics-based ranking of materials—including seat composites, sound-deadening layers, electrical insulation, and carpet assemblies—based on their intrinsic ability to delay their own temperature rise under transient heat flux. By integrating materials with a high τ and elevated critical failure temperatures, this study proposes a performance-based material selection strategy. This strategy is critical for extending the safe egress period mandated by standards such as UN ECE R.100 and GB 38031-2020 and is increasingly vital as safety benchmarks evolve toward longer durations. The synthesis of high-inertia materials with traditional fire-resistant insulation provides a multi-layered defense, enhancing passenger protection by functionally delaying the progression of heat, fire, and hazardous emissions into the occupied cabin space.

El-Sharkawy, Alaa, Taha, Nahla, Asar, Mona, Sheta, Mai

Enhanced CAE Methodology to Predict Bolt Shear Failure Using Multi-Layer Approach

2026-01-0489

4/7/2026

Automotive seat system is one of the most complex systems in vehicle for its technical and functional requirements. Seat is designed to meet all regulatory requirements subjecting it to multiple tests with loading patterns which caters to the occupant safety. Varied loading and load path for different test requirements cause seat bolts to experience tensile, compressive, bending moments and shear loading. Shearing along bolt length is one of the common failure modes observed during design validation by physical tests. In the world of CAE, there is an industry approach to find the bolt failures at nut and head for all kind of loads. But shear failures along varied bolt lengths are not accurately predictable as multiple sheet metal parts will transfer loads unevenly onto bolt length and it becomes challenge to find which component is leading to shear failure. Hence by adding multiple rupture layers across the bolt length shear and its location could be predicted. Further, to resolve the bolt shear issues, engineers generally try to modify the component design for better energy absorption, but our research found that, only by increasing the clearance around bolt hole will resolve the bolt shear issues. During one of such failures, a new approach of adding multiple rupture layers along bolt length was used which predicted the shear failure modes and location of shear as observed in physical tests. The CAE bolt model thus updated with new procedure for all such future bolt shear failure prediction in seat structure models.

RJ, Jethendra, Chiu, Li-Ban

Quasi-Static Head Restraint Pull-Tests to Assess Retention Performance: Maximum Load and Damage Characteristic

2026-01-0564

4/7/2026

Head restraint requirements and designs have evolved to minimize the delay in head support and reduce differential loading in the neck. As a result, head restraints have become bigger and more angled forward, sitting, closer to the occupant’s head. Head restraints separation from seatbacks are sometimes observed in the field. Are head restraint detachments resulting from occupant comfort issues prior to the crash, occupant loading during the crash or were they removed by emergency personnel for extrication? Understanding the retention strength of head restraints and the type of evidence left behind by a forced removal may help researchers resolve the question of how a head restraint may be found post-crash separated from the seat. Quasistatic pull tests were conducted to measure vertical retention capabilities, compare vertical adjustment and release mechanisms, and document deformation and damage. Eighteen different front seat head restraint designs were evaluated. The model years ranged from 2014 to 2019. All head restraints complied with FMVSS 202A requirements. Each head restraint design was tested in two tension loading configurations: In-line nominal pull and 45-degree pull. In the nominal configuration, the head restraints were pulled vertically upwards, in line with the adjustment posts. Additionally, head restraints were pulled at a 45-degree angle to the ground in the 45-degree configuration. The force at detachment averaged 1,758 ± 559 N for the in-line tests and 2,505 ± 662 N for the 45 degree pull tests. Damage was observed in all 36 tests and was evidenced by deformation in the locking mechanism and/or the guide sleeve being displaced out of the seatback. Detachment occurred due to overload or deformation of the locking mechanism or the guide sleeve being pulled out of the seatback. Bypassing detachment occurred in 21 of the tests while detachment from guide sleeve separation resulted in 15 of the tests. Half of the head restraints were equipped with two locking sides and half with one side. However, there does not appear to be a correlation between peak force and number of locking sides. There are currently no head restraint retention regulations for tensile loading. This study is a first to document head restraint separation resulting from forceful loading. The damage was documented in detail. This information may assist in answering the questions posed above.

Parenteau, Chantal, Burnett, Roger, Davidson, Russell

Numerical Investigation on Thorax Rib Deflections of 50th Male in Vehicle Side Oblique Pole Impact Using Human Body Model

2026-01-0566

4/7/2026

The WorldSID-50M dummy is widely adopted in regulatory and third-party testing programs (e.g., ECE, Euro-NCAP, C-NCAP) owing to its advanced design and superior biofidelity. However, in vehicle side oblique pole crash tests involving shoulder-covered side airbags - an expanded testing modality - excessive deflection of the upper thoracic ribs was observed. Notably, this phenomenon was absent in standard side moving deformable barrier (SMDB) tests. This study pursued two core objectives: (1) to systematically document the excessive upper thoracic rib deflection of the WorldSID-50M dummy in side oblique pole crash tests; and (2) to investigate the influence of arm-thorax interaction on such deflection using a Human Body Model (HBM) representative of a 50th percentile male occupant. Numerical simulation results reveal that while arm-thorax interaction does contribute to rib deflection, its impact on the excessive deflection of the upper thoracic ribs is negligible.

Zhou, DY, Chen, Shaopeng, Yan, Li, Wu, Jing, Liu, Chong, Lv, Xiaojiang, Yang, Heping

Development of Automotive Hood Using Multi-Material Double Injection Molding – An Overview

2026-01-0476

4/7/2026

This paper presents the multidisciplinary development of a hybrid automotive hood manufactured using double-shot injection molding with overmolded brackets. Conventional steel and aluminum hoods, while structurally reliable, pose challenges in terms of weight reduction, pedestrian head protection, and manufacturing cost. Composite and thermoplastic alternatives supported by computational analysis and advanced molding processes provide opportunities to address these challenges. Finite element analysis (FEA) was employed to evaluate torsional and bending stiffness, locking load, and crashworthiness, while pedestrian headform simulations following ECE R127 and EEVC WG17 guidelines were conducted to assess compliance with safety regulations. Adhesion and bonding strength of overmolded polymer–polymer interfaces were studied to validate manufacturing feasibility. Results confirm that hybrid hoods fabricated using multi-material double-shot molding can achieve weight reductions of up to 30% compared with steel, maintain structural stiffness equivalent to aluminum, meet head injury criterion (HIC) thresholds, and reduce assembly complexity by consolidating brackets and reinforcements into a single integrated structure.

Ganesan, Karthikeyan, Seok, Sang Ho, Jo, Hyoung Han

Effective Design Method for Lightweight Suite of Seats Considering Crashworthiness and Cost

2026-01-0493

4/7/2026

This paper presents a methodology for designing and evaluating lightweight, crashworthy aircraft seats that meet 21g crash safety standards and injury criteria. Four seat classes—double economy, single economy, premium economy, and business—were developed using a modular design strategy focused on part commonality (family of parts) and manufacturability. A shared family of structural components was implemented across all seat types, with dimensional modifications applied only, when necessary, due to differences in seat width or height. In such cases, the same material systems and design principles were used to ensure consistency and reduce manufacturing complexity. The designs were evaluated using finite element simulations to verify performance under aerospace crash conditions. Each seat configuration was validated against regulatory crashworthiness criteria and injury thresholds, including pelvic, lumbar, and femur compressive forces, as well as head injury criteria (HIC) values. The final designs successfully passed all crash and most injury thresholds, achieving regulatory compliance while maintaining a lightweight structure. This marked a significant improvement over a baseline seat configuration that failed to meet crash or injury requirements. By combining modularity with performance-driven design, this approach delivers a flexible and manufacturable seat family that balances safety, weight, and cost. The methodology offers broader applicability for occupant protection systems in automotive and aerospace domains, where lightweighting and regulatory compliance remain critical design challenges.

Gray, Savannah, Orr, Mathew, Shi, Yifan, Park, Taeil, Lee, Jake, Wotten, Erik, LeFrancois, Richard, Huang, Yuhao, Patel, Anuj, Kim, Hansu, Burns, Nicholas, Jalayer, Shayan, Grant, Robert, Kok, Leo, Hansen, Eric, Kim, Il Yong

Revisiting Rear Seat Safety: Field Evaluations of Relative Injury Risk Across Seating Positions and the Integration of Advanced Rear Seat Belt Systems

2026-01-0561

4/7/2026

Despite advances in crash avoidance, occupant restraint systems remain crucial in protecting the motoring public. Following decades of improvement in occupant protection, including several supplemental restraint systems for front seat occupants, the safety of rear seat occupants has recently undergone scrutiny. Studies evaluating rear seat occupant injury risk via field crash data have reported reduced relative safety in rear seating positions and alluded to advanced rear seat restraints, such as pretensioners and load limiters, as potential solutions. While the pursuit of novel technologies has historically improved occupant outcomes, evaluation of new systems in both controlled laboratory environments and field crashes is necessary to understand potential consequences of widespread introduction. This study analyzed the prevalence of advanced seat belts (load limiters and pretensioners) in the rear seating positions in the U.S. fleet. Additionally, occupant injury risk was compared across vehicles equipped with conventional and advanced seat belts in the rear seat, as well as between rear and front seat occupants, using data from state crash databases. The proportion of vehicles equipped with advanced rear seat restraints has steadily increased over the past couple of decades, but, as of 2023, remained below 10% of registered vehicles on US roadways. Evaluation of police-reported field crash data indicated that lap-shoulder belted rear seat occupants sustained fatal or incapacitating injury at a lesser rate than front seat occupants. Rear seat occupants have historically been and remain well-protected. Current field data do not consistently demonstrate a statistically significant reduction in rear seat occupant injury or fatality risk attributable to advanced seat belts. However, the relatively low number of crashes involving serious injury or fatality for rear-seated occupants in vehicles equipped with these systems underscores the need for additional data to fully evaluate their effectiveness in real-world crashes.

Rapp van Roden, Elizabeth Ann, Miller, Bruce, Pearson, Joseph, Williamson, James, Brown, Thomas

Statistical Assessment of Pretensioner and Load Limiter Effects on the Large Omnidirectional Child ATD Response in Frontal Impacts

2026-01-0550

4/7/2026

Enhancing child occupant protection requires a clear understanding of how seatbelt restraint parameters influence crash injury metrics. Real-world vehicles mostly include pretensioner and load limiter technologies to mitigate injuries, but rear seat restraints often do not include these. The FMVSS No. 213 test bench closely represents current restraint systems but does not involve such active vehicle restraint features. This study explores the response of the Large Omnidirectional Child ATD to evaluate potential injury mitigation under FMVSS No. 213 frontal sled test conditions. A simulation-based full factorial design was implemented in LS-DYNA to vary pretensioner retraction, retractor load-limiting thresholds, and webbing payout, with injury measures including head acceleration, head excursion, chest compression, and abdominal pressure twin sensors (APTS). Statistical evaluation using analysis of variance (ANOVA) and Tukey-Kramer post-hoc tests quantified main and interaction effects. Pretensioners consistently reduced head excursion and acceleration, while load limiters lowered chest compression but increased excursion, illustrating a performance trade-off. Webbing payout behavior showed strong coupling to load-limiting thresholds, revealing notable parameter interdependencies. These results demonstrate that integrating pretensioners and load limiters into child restraint systems could yield meaningful safety benefits but must be optimized holistically to balance competing injury metrics. The study provides both empirical insight and a statistical framework for evaluating advanced restraint configurations in pediatric occupant simulations.

Khattak, Mohid Muneeb, Bendig, Colleen, Louden, Allison, Noll, Scott

Leveraging Machine Learning for Occupant Body Size Estimation via B-Pillar Seatbelt Systems

2026-01-0559

4/7/2026

Occupant body size in vehicles varies significantly, encompassing differences in height, mass, and overall body composition. Adaptive restraint systems, featuring adjustable parameters such as belt load limiters, steering column load limiters and stroke, seat pan stiffness, and airbag pressure, can offer more equitable protection tailored to individual body sizes. In this study, a test rig modeled after the Volvo XC90 (2016) was used to collect data from 46 participants who were dressed in typical summer clothing and seated upright, without slouching or leaning sideways. Stepwise adjustments of the seat pan and seatback were performed. The collected measurements include seat pan movements (front-back and up-down), seatback recline, and key seatbelt-related parameters, such as belt payout length, D-ring angle, lap belt length, and buckle tension. The collected data was then used to train machine learning models to predict individual occupant characteristics: standing height, mass, and seated height. This study shows the challenges and opportunities for occupant body size estimation from seatbelt and seat location inputs. The prediction’s root mean square error across validation dataset was as follows: standing height 8.76cm, mass 11.33kg, and seated height 5.61cm. The prediction of mass fulfilled the defined criterion, while the prediction accuracy for standing height and seated height require further improvement. Our analysis reveals that a key improvement could be achieved by implementing an upgraded lap belt position sensor, given that lap belt length was identified as a dominant feature across models. Furthermore, the analysis suggests that D-ring angle, buckle tension, and seatback recline can be excluded from the input feature set.

Wang, Da, Ahmed, Jawwad, Rowe, Mike, Brase, Dan

Aircraft Tow Bar

ARP1915E (Current)

2/12/2026

This SAE Aerospace Recommended Practice (ARP) specifies dimensional and physical requirements of tow bar connections to tractor and aircraft (see Figure 1). It is applicable to all types of commercial transport category aircraft tow bar. The purpose of this SAE Aerospace Recommended Practice (ARP) is to standardize tow bar attachments to airplane and tractor according to the mass category of the towed aircraft, so that one tow bar head with different shear levels can be used for all aircraft that are within the same mass category and are manufactured in compliance with AS1614 or ISO 8267.

AGE-3 Aircraft Ground Support Equipment Committee

Improve Safety Balance between Women and Men in Frontal Crashes through Parametric Human Modeling and Adaptive Design Optimization

2025-22-0010

1/23/2026

Objective: Previous studies have reported disparity in injuries between male and female drivers in the risk of certain types of injuries in frontal crashes that may be due to a myriad of sex-related differences, including body size, shape, anatomy, or sitting posture. The objectives of this study are 1) to use mesh-morphing methods to generate a diverse set of human body models (HBMs) representing a wide range of body sizes and shapes for both sexes, 2) conduct population-based frontal crash simulations, and 3) explore adaptive restraint design strategies that may lead to enhanced safety for the whole population while mitigating potential differences in injury risks between male and female drivers Method: A total of 200 HBMs with a wide range of body sizes and shapes were generated by morphing the THUMS v4.1 midsize male model into geometries predicted by the statistical human geometry models. Ten male and ten female HBMs were selected for population-based simulations. An existing automated simulation framework was leveraged to rapidly set up crash simulations with the morphed HBMs and previously-validated driver compartment and restraint models. A total of 1,000 frontal crash simulations were performed under varied restraint designs and crash severities. A surrogate model was developed based on the simulation data using a Gaussian Process (GP) method. Two design optimization schemes were used to flexibly adjust design parameters based on subject variables to minimize population injury risks while minimizing differences in injury risk between male and female HBMs. Key Results: The simulations indicated that the joint injury probability (Pjoint) is more sensitive to the seatbelt and driver airbag variables at 35 mph, while the variability is greatly reduced at 25 mph for all design variables. The optimal adaptive design strategy from these models suggested a higher seat belt load limit, higher airbag inflation pressure, smaller airbag venting, and higher steering column force for occupants with higher body mass index (BMI). The adaptive design reduced the population Pjoint by 19.6%, 31.8% and 38.8% from the baseline design when Delta-V equals to 25, 30 and 35 mph, respectively. For high speed crashes (Delta-V = 35 mph), the proposed adaptive design reduced the average Pjoint differences between men and women from 24.02% to 2.84% compared to the baseline design. Surprisingly, a restraint strategy constrained to sex-based balance is able to maintain similar injury risks between male and female drivers. Major Conclusion: This study is the first to integrate finite element crash simulations with adaptive restraint design optimization to potentially reduce population injury risks and safety balance between male and female occupants. Gaussian process was shown to be an effective surrogate to FE simulations.

Sun, Wenbo, Hu, Jingwen, Lin, Yang-Shen, Boyle, Kyle, Reed, Matthew, Sun, Zhaonan, Hallman, Jason

Crashworthiness of WC19 Wheelchairs in Horizontal Dynamic Aircraft Seating Tests

09-14-02-0001

1/23/2026

At present, commercial air travel rules do not allow people to sit in their own wheelchairs during flight. However, airline seating often does not meet medical needs. In response to current requests to allow this seating option, we researched the crashworthiness and safety of wheelchairs for potential use in aircraft. For motor vehicle travel, many wheelchairs meet voluntary standards for crashworthiness and safety per RESNA WC19. This project assesses whether WC19-compliant wheelchairs can meet FAA aircraft seating standards when secured using 4-point tiedowns. For the FAA horizontal impact testing, computer modeling indicated that a trapezoidal sled pulse was sufficient to represent the more typical triangular pulse, and that due to the flexibility of the tiedown webbing, the effect of the simulated pitch/roll element was minimal. During the initial two horizontal impact tests, fracture of the left front wheelchair caster was observed. The remaining five wheelchairs were tested with an added vehicle-mounted lap belt and were successful at meeting occupant retention and structural integrity requirements. The outcomes show that it may be possible for people to remain seated in a WC19-compliant wheelchair for air travel without a significant decrement in safety.

Klinich, Kathleen D., Manary, Miriam A., Boyle, Kyle J., Vallier, Tyler, Orton, Nichole R.

Integrated Evaluation of Pre-Crash Braking and Crash Injury Outcomes Using Human Body Models and ATDs

2026-26-0019

1/16/2026

Traditionally, occupant safety research has centered on passive safety systems such as seatbelts, airbags, and energy-absorbing vehicle structures, all designed under the assumption of a nominal occupant posture at the moment of impact. However, with increasing deployment of active safety technologies such as Forward Collision Warning (FCW) and Autonomous Emergency Braking (AEB), vehicle occupants are exposed to pre-crash decelerations that alter their seated position before the crash. Although AEB mitigates the crash severity, the induced occupant movement leads to out-of-position behavior (OOP), compromising the available survival space phase and effectiveness of passive restraint systems during the crash. Despite these evolving real-world conditions, global regulatory bodies and NCAP programs continue to evaluate pre-crash and crash phases independently, with limited integration. Moreover, traditional Anthropomorphic Test Devices (ATDs) such as Hybrid III dummies, although highly repeatable, lack the bio-fidelity necessary to capture human-like kinematics during pre-crash braking events involving low g. ATDs do not simulate the spinal articulation, posture adjustments and active muscle contraction that occur during emergency maneuvers or pre-crash scenarios. To overcome these limitations, researchers have increasingly turned to Human Body Models (HBMs) such as Total Human Model for Safety (THUMS) and Global Human Body Model Consortium (GHBMC). These models enable high-fidelity finite element (FE) simulations with anatomical realism, allowing for the inclusion of active musculature and posture changes. This study aims to quantify the occupant forward excursion under pre-crash phase (due to AEB) and explore the possibility of an integrated simulation framework that evaluates occupant safety across both pre-crash and crash events. For this, the approach was to carry out full vehicle braking tests (1g braking pulse) with adult male (AM50) volunteers at different speeds to measure forward head excursion during pre-crash. These scenarios were replicated in LS-Dyna using THUMS HBM, showing strong agreement with experimental data. The resulting excursed postures were then used in crash simulations with ATDs to evaluate the effect on injury outcomes. Overall, the findings demonstrate effect of forward excursion on occupant injuries and the effectiveness of HBMs in capturing occupant kinematics, during pre-crash events.

Pendurthi, Chaitanya Sagar, THANIGAIVEL RAJA, T, Kondala, Hareesh, Sudarshan, B.Sudarshan, Nehe, Vaibhav, Rao, Guruprakash

Items per page:

1 – 50 of 4086