Browse Topic: Occupant protection

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A Comprehensive Review of System Risk in Automotive Crash Safety15-19-02-00106/9/2026
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.
Assessing the Influence of Reclined Vehicle Seatback Configurations with and without a Belt-Positioning Booster on Child Posture via Pressure Mapping09-14-01-00045/4/2026
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 Safety09-14-01-00075/4/2026
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
Comparative Analysis of Thoracic Injury and Causative Factors across Sexes in Serious Frontal Motor Vehicle Collisions in the Crash Injury Research and Engineering Network Database09-14-01-00315/4/2026
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 Seating09-14-01-00035/4/2026
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
Securing Child Restraint Systems in Motor VehiclesJ1819_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
Statistical Assessment of Pretensioner and Load Limiter Effects on the Large Omnidirectional Child ATD Response in Frontal Impacts2026-01-05504/7/2026
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
Effective Design Method for Lightweight Suite of Seats Considering Crashworthiness and Cost2026-01-04934/7/2026
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
Enhanced CAE Methodology to Predict Bolt Shear Failure Using Multi-Layer Approach2026-01-04894/7/2026
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
Injury Risk Analysis of Occupant with Different Lower Limb Postures under the Frontal Impact Sled Conditions2026-01-05724/7/2026
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
Application of DFSS for Optimizing Thermal Protection in Electric Vehicles during Battery Thermal Runaway Events2026-01-01424/7/2026
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
Guidelines for Interior Material Selection to Enhance Thermal Safety in Electric Vehicles2026-01-02494/7/2026
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
Occupant and Seat Responses in Various Moderate- to High-Speed Rear Impact Conditions: Focus on Head-to-Head Restraint Interactions2026-01-05654/7/2026
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
Potential Regulatory Approaches for Occupant Safety in Automated Vehicles with Unique Seating Configurations – Part 2: Interior Safety Sensing and Messaging Proposals2026-01-05764/7/2026
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
Revisiting Rear Seat Safety: Field Evaluations of Relative Injury Risk Across Seating Positions and the Integration of Advanced Rear Seat Belt Systems2026-01-05614/7/2026
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
Machine Learning Based Meta-Analysis of IIHS Moderate Overlap Frontal Crash Test for Rear Seat Occupant Safety Performance2026-01-05794/7/2026
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
HaloBus: Edge Computing-Enabled Real-Time Boarding and Exit Detection for Enhanced Transportation Safety Using Lightweight AI2026-01-05554/7/2026
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
Potential Regulatory Approaches for Occupant Safety in Automated Vehicles with Unique Seating Configurations – Part 1: Occupant Protection Proposals2026-01-05784/7/2026
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
Quasi-Static Head Restraint Pull-Tests to Assess Retention Performance: Maximum Load and Damage Characteristic2026-01-05644/7/2026
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
Development of Automotive Hood Using Multi-Material Double Injection Molding – An Overview2026-01-04764/7/2026
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
Aircraft Tow BarARP1915E (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
Crashworthiness of WC19 Wheelchairs in Horizontal Dynamic Aircraft Seating Tests09-14-02-00011/23/2026
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.
Method and System of Detecting Obstacle around Vehicle Door2026-26-00261/16/2026
Vehicle door-related accidents, especially in urban environments, pose a significant safety risk to pedestrians, infrastructure and vehicle occupants. Conventional rear view systems fails to detect obstacles in blind spots directly below the Outside Rear View Mirror (ORVM), leading to unintended collisions during door opening. This paper presents a novel vision-based obstacle detection system integrated into the ORVM assembly. It utilizes the monocular camera and a projection-based reference image technique. The system captures real-time images of the ground surface near the door and compares them with calibrated reference projections to detect deviations caused by obstacles such as pavements, potholes or curbs. Once such an obstacle is detected the vehicle user is alerted in the form of a chime.
Bhuyan, Anurag, Khandekar, Dhiraj, Jahagirdar, Shweta
Enhancing EV Battery Safety: Progressive Crushing and Energy Absorption Technique2026-26-01891/16/2026
A crash energy absorption technique and method improve the safety and structural integrity of electric vehicle battery packs during collisions, complying with global regulations. This analysis details an assembly featuring a battery housing for mounting battery cells, a crash member connected to the battery housing's periphery, and flexural members linked to the crash member. The flexural members are designed to absorb impact forces by deforming and storing potential energy during sudden impacts. This approach ensures energy is stored within the flexural elements and then transferred to the battery cells through progressive crushing. The design effectively delays intrusion, enhances battery safety, and minimizes cell-level damage. This solution improves occupant safety and prevents thermal runaway incidents while maintaining the battery's overall performance and reliability in EVs.
Amberkar S, Sunil, Lakshman singh, Meenakumari, Bodaindala, Anil Kumar
Multi-Material Front Structures: A Pathway to Safer and More Sustainable Vehicle Design2026-26-04561/16/2026
Frontal crash structures play a vital role in occupant safety, but traditional designs often involve a trade-off between structural strength and weight efficiency. In the pursuit of safer and more sustainable mobility, this study explores a physics-based methodology that leverages the principle of dynamic equilibrium to guide the integration of dissimilar materials in front-end vehicle structures. Specifically, examined a novel configuration wherein aluminum High-pressure die cast (single HPDC part) is introduced which covers swan neck region as well as the base of the front longitudinal member, while retaining steel in the frontal crush zone. This arrangement aims to redistribute crash loads and control deformation mechanisms, enabling improved energy absorption without compromising structural integrity. To evaluate the proposed strategy, a series of detailed finite element simulations were conducted using LS-DYNA, a widely adopted tool for vehicle crash analysis. The results reveal that the dynamic equilibrium approach offers a rational and most efficient framework for material allocation, allowing for the optimization of crash performance metrics while simultaneously achieving weight reduction. Compared to conventional all-steel or all-aluminum designs, the hybrid structure demonstrate efficient, improved crashworthiness, with measurable mass savings. By grounding material decisions in mechanical principles rather than empirical iteration, this research presents a scalable methodology applicable to a wide-range of vehicle platforms. The outcomes offer a compelling case for the adoption of multi-material architectures as a pathway toward enhanced crash safety and reduced environmental impact.
Revanth, Goshika, Bhagat, Milind, Joshi, Vikas, Mankhair, Abhijit, Sudarshan, B.Sudarshan, Kollipara, Jahanavi
Rear-Facing Infant Seat Structural Integrity and Crashworthiness under Front Seatback Loading in Rear-Impact Collisions2026-26-05541/16/2026
Rear-facing infant seats that are positioned behind front outboard vehicle seats are at risk of being compromised by the rearward yielding of occupied front seat seatbacks during rear-impact collisions. This movement can cause the plastic shell of the infant seat to collapse and deform, increasing the risk of head injuries to the infant. Current designs of rear-facing infant seats typically do not consider the loading effects from the front seatback during rear-impact situations, which results in weak and collapsible shell structures. Moreover, regulatory compliance tests, such as FMVSS 213, do not include assessments of rear-facing infant seats under realistic rear-impact conditions. as the bench used for the regulatory test lacks realistic vehicle interior components. This study emphasizes the need for revised testing methodologies that employ sled tests with realistic seatback intrusion conditions to facilitate the development of improved infant seat designs. Research shows that rear-facing infant seats designed for real-world loading conditions can improve safety and injury outcomes for infants in severe rear-impact collisions in the presence of front-occupied seats.
Thorbole, Chandrashekhar
Characterization and Material Card Calibration of PU Foam Under Various Strain Rates for Crash Simulation2026-26-04641/16/2026
PU foam shows a excellent energy absorbing dissipation properties during impact load so it commonly used in car seats, cabin and crash protection system. Specifically, in vehicle seats PU foams play a critical role in protecting occupants during crash scenarios by absorbing energy, distributing forces, and improving seatbelt performance, additionally providing countermeasures for head impact protection. The movement of the seat and the direction of the force during crash testing are highly unpredictable. The material behaviour of PU foam is captured using an isotropic, hyper-elasticity-based constitutive model available in LS-DYNA through MAT_083. This model is designed to take into account the foam's compressibility, sensitivity to strain rates, low Poisson's ratio, and hysteresis. The characterization of a PU foam with a nominal density of 65 kg/m3 was performed using quasi-static compressive testing of 0.01/s and dynamic compressive testing of 1/s,13/s, 120/s, as well as a quasi-static tensile test of 0.01/s. The material response data were used to calibrate the LS-DYNA foam model MAT-FU CHANG FOAM MAT-083. Calibration of the LS-DYNA material card (*MAT_FU_CHAN_FOAM MAT-083) was performed using coupon-level test data. The goal was to accurately simulate the foam's behaviour under varying strain rate conditions and extract the deformation pattern. Finally, the simulations were conducted with the same geometry and loading conditions as the experimental setup. The performance of the material card was validated by comparing simulation results with experimental data, demonstrating its ability to replicate foam behaviour under crash conditions.
Gaurav, Ashish Kumar, Krishnamoorthy, Kunju, Varatharajan, Senthilkumaran
Influence of Impact Configuration on Rear Compartment Intrusion and Structural Countermeasures2026-26-04621/16/2026
The impact configuration has a strong influence on the rear seat survival space intrusion pattern during severe rear-impact collisions. The relative contributions of rear seat pan forward intrusion versus rear seatback intrusion vary depending on the nature of the crash. In underride impacts, the rear wheels are pushed forward into the occupant survival space from below, causing the rear seat-pan to move forward and upward relative to the vehicle interior. Conversely, override impacts tend to produce direct seatback intrusion into the rear compartment. This study used a validated computer model from the NHTSA website to simulate various types of rear compartment intrusions under different impact configurations. The analysis also assessed structural countermeasures designed to minimize occupant survival space intrusion. The results demonstrate that underride impacts primarily drive the forward motion of the rear wheels into the structure, establishing load paths that lead to structural failures and forward propulsion of the seat pan, in contrast to the seatback-dominant intrusion observed in override impacts. Furthermore, the study shows that structural reinforcements located above, and below the beltline are effective in mitigating survival space intrusion across different rear-impact scenarios.
Thorbole, Chandrashekhar, Vhanaje, Manoj G, Eknath Chopade, Santosh
Experimental Evaluation of High Energy Impact Test of Wheel Rim2026-26-05041/16/2026
High energy impact testing using free fall mass is a crucial method for evaluating the structural integrity, and safety performance of automotive components subjected to sudden impact forces. This study focuses on assessing critical parts such as wheel rims, suspension knuckles, commonly exposed to unintentional impacts during vehicle operation, maintenance, or collisions. The test involves dropping a standardized mass from predetermined heights onto the component to simulate real-world impact scenarios. Key performance indicators include deformation, crack propagation, fracture resistance, and energy absorption capacity. Wheel rims and knuckles are evaluated for their ability to maintain structural integrity under localized impact without compromising vehicle handling or safety. Seats and related interior structures are tested to ensure occupant protection during crash-like events. Other components, such as brackets, mounts, or housings, are included based on functional criticality and exposure risk. Results from the free fall impact tests inform design optimizations, material selection (e.g., aluminium alloys, composites, high-strength steels), and manufacturing processes to improve product reliability and compliance with automotive safety requirements. This approach supports the development of robust vehicle systems capable of withstanding harsh real-world conditions, ultimately enhancing vehicle safety, performance, and customer satisfaction.
Roham, Prasad, Bagade, Mohan, Sinnarkar, Nitin, Pawar, Prashant R, Shinde, Vikram
Integrated Evaluation of Pre-Crash Braking and Crash Injury Outcomes Using Human Body Models and ATDs2026-26-00191/16/2026
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
Geometrical Assessment of the Curtain Airbag Coverage in Indian Passenger Vehicles2026-26-00211/16/2026
Curtain airbags are the most effective protective systems to prevent severe/fatal head injuries in side collisions with narrow objects such as poles or trees. One of the important parameters of curtain airbags is the inflated zone i.e. the coverage area of the airbag, which decides the extent of head protection for occupants with different anthropometries in different seating rows. EuroNCAP first introduced the concept of Head Protection Device Assessment (HPDA) in 2015., In addition to the performance requirements in the dynamic test, EuroNCAP started assessing the deployed curtain airbag/s for its area coverage and verification of inflated zones for various anthropometries over occupant rows. In India, there is now a near total adoption of curtain airbags as standard fitment by the OEMs. Further, introduction of Bharat NCAP (BNCAP), a Perpendicular Pole Side Impact test is conducted for assessing the effectiveness of curtain airbags in a dynamic test, but currently, does not perform the HPD assessment. The paper studies the Head Protection Device/Curtain Airbags offered in Passenger Vehicles in India w.r.t. the Head Protection Device Geometric Assessment (HPDA). This assessment analyses the effectiveness of curtain airbags present in Indian passenger vehicles for protection of occupants of different anthropometries. The study is conducted on the vehicles that have been tested at ARAI and are also currently under sale in the Indian market.
Jaju, Divyan, Kulkarni, Dileep, Mahajan, Rahul
Adaptive Restraints for Equitable Protection2026-26-00151/16/2026
Real-world crashes involve diverse occupants, but traditional restraint systems are designed for a limited range of body types considering the applicable regulations and protocols. While conventional restraints are effective for homogeneous occupant profiles, these systems often underperform in real-world scenarios with diverse demographics, including variations in age, gender, and body morphology. This study addresses this critical gap by evaluating adaptive restraint systems aligned with the forthcoming EURO NCAP 2026 protocols, which emphasize real-world crash diversity and occupant type. Through digital studies of frontal impact scenarios, we analyze biomechanical responses using adaptive restraints across varied occupant demographics, focusing on head and chest injury (e.g., Chest Compression Criterion [CC]). This study used a Design of Experiments (DOE) approach to optimize occupant protection by timing the actuating of these adaptive systems. The results indicate that activating adaptive seatbelts and airbags before reaching peak chest and pelvis accelerations can help reduce injuries. The study suggests a rule-based framework for adaptive restraints, demonstrating that injury optimization correlates strongly with time control of restraint parameters. These insights advance the development of occupant-centric safety systems, offering scalable solutions for emerging regulatory standards and enhancing protection for underrepresented demographics in vehicular safety engineering.
satija, Anshul, Suryawanshi, Yuvraj, Chavan, Avinash, Rao, Guruprakash
Real-Time Helmet Detection and Closed-Loop Enforcement System for Two Wheelers2026-26-06501/16/2026
Asian countries capture a significant share of global two-wheeler usage, with India consistently ranking among the top three countries. 2 wheelers are a significant portion of road traffic and contribute heavily to the national burden of road fatalities. Despite regulatory mandates, helmet non-compliance remains widespread due to limited enforcement reach and behavioural inertia. The current strategies for enforcement, such as traffic policing or external camera-based surveillance, are reactive, infrastructure-dependent, are ineffective at scale. To address these limitations, we propose system that will detect if the user is wearing the helmet. The system is designed and packaged to be integrated into the 2-wheeler directly and then execute functions in real-time for helmet noncompliance. The software algorithm is an AI-powered, vision-based system that leverages deep learning techniques for helmet detection. This model is enforced with a custombuilt dataset accommodating cultural and regional variations. Further model is trained and optimized so that it also perform accurately under conditions, including variable lighting, occlusions, and diverse headgear styles commonly seen in the Indian context. The overall system is further optimized for low-power, real-time inference suitable for embedded platforms on two-wheelers. Once the helmet is not detected, the system generates a two-stage response: an audible alert warns the rider, and if non-compliance persists, the vehicle can trigger a controlled deceleration mode through a closedloop actuation strategy, bringing it to a safe stop. The evaluation results indicate a detection accuracy of 97% under varied real-world conditions, establishing the feasibility of intelligent, vehicle-integrated enforcement for two-wheelers in the Indian context.
Kandimalla, Om Mahalakshmi, Shah, Ravindra, Karle, Ujjwala
Crash Pulse Characterization for the Passenger Vehicle Fleet in India2026-26-00291/16/2026
A crash pulse is the signature of the deceleration experienced by a vehicle and its occupants during a crash. The deceleration-time plot or crash pulse provides key insights into occupant kinematics, occupant restraints, occupant loading and efficiency of the structure in crash energy dissipation. Analysing crash pulse characteristics like shape, slope, maximum deceleration, and duration helps in understanding the impact of the crash on occupant safety and vehicle crashworthiness. This paper represents the crash pulse characterization study done for the vehicles tested at ARAI as per the ODB64 test protocol. Firstly, the classification and characterization of the crash pulses is done on the basis of the unladen masses of the vehicles. The same are further analysed for suitability of mathematical waveform models such as Equivalent Square Wave (ESW), Equivalent Triangular Wave (ETW), Equivalent Sine Wave (ESW), Equivalent Haversine Wave (EHSW) as well as EDTW (Equivalent dual trapezia wave) or Bi Slope Approximation model for the characterization. These mathematical wave diagrams are then utilized for analysing the crash behaviour and its probable effect on the injury probability. Such a study can be used by design engineers to model the front-end stiffness of the vehicle frontal structure. This can further help to optimize the dummy restraint modifications to minimize the occupant injury.
Mishra, Satish, Kulkarni, Dileep, Borse, Tanmay, Mahindrakar, Rahula Ashok, Mahajan, Rahul, Jaju, Divyan
Safer Trucks for India: Smart Tech Fusion2026-26-00311/16/2026
Commercial vehicle sector (especially trucks) has a major role in economic growth of a nation. With improving infrastructure, increasing number of trucks on roads, accidents are also increasing. As per RASSI (Road Accident Sampling System India) FY2016-23 database, commercial vehicles are involved in 42% of total accidents on Indian roads. Involvement of trucks (N2 & N3) is over 25% of total accidents. Amongst all accident scenarios of N2 &N3, frontal impacts are the most frequent (26%) and causing severe occupant injuries. Today, truck safety development for frontal impact is based on passive safety regulations (viz. front pendulum – AIS029) and basic safety features like seatbelts. In any truck accident, it is challenging rather impossible to manage comprehensive safety only with passive safety systems due to size and weight. Accident prevention becomes imperative in truck safety development due to extremely high energy involved in front impact scenarios. The paper presents a unique safety development approach (for frontal impact safety development for N2 and N3 trucks) which enables smart synthesis of active and passive safety systems to comprehensively address real world safety. Four major areas are identified for truck safety development viz. structural crashworthiness, compatibility, occupant safety and ADAS (Advanced Driver Assistance System). The innovation lies in smart mix of these areas during product safety development. The study presents the safety development of light commercial vehicle (truck) with this approach. Structural crashworthiness & occupant safety are developed with extensive number of CAE simulations. Design is physically validated with frontal impact test. In addition, extensive mileage accumulation is generated across Indian roads to validate ADAS system performance.
Joshi, Kedar Shrikant, Gadekar, Ganesh, Date, Atul, Koralla, Sivaprasad
Achieving Robust Sensing Performance for Six-Airbag Systems: Design Approaches and Validation Techniques for Side Sensing2026-26-00301/16/2026
The proposal of GSR 16(E) in India promotes six airbags in passenger vehicles, aiming to enhance occupant safety. In parallel, the new Bharat New Car Assessment Program (BNCAP) outlines performance protocols that demand robust airbag deployment strategies to achieve a five-star safety rating. One of the critical challenges in meeting both regulatory and consumer safety expectations is the optimal packaging of the airbag Electronic Control Unit (ECU) and its associated impact sensors. These must perform reliably across regulatory tests, BNCAP protocols, and real-world accident scenarios. The location of side acceleration ‘g’ side impact sensors—whether mounted on the side sill, B-pillar, C-pillar, or door structures—is pivotal to achieving consistent and timely side airbag deployment. These sensors must also demonstrate immunity to false triggers or missed events in both static and dynamic misuse and abuse conditions. Ensuring robust sensor performance under these varied conditions is key to the success of the system. This study focuses on evaluating acceleration-based side impact sensors placed at different locations within the vehicle structure, assessing their sensitivity and correlation with airbag deployment performance. Additionally, for compact vehicles where faster deployment of side airbag is essential, the use of pressure-based sensors was investigated. The findings of this study were instrumental in finalizing the optimal packaging strategy for both acceleration and pressure sensors in six-airbag systems.
Kudale, Shailesh, Rao, Guruprakash, wayal, Virendra, Goswami, Tarun
Investigating Pelvic Locking and Torso Kinematics Using Human Body Models in Frontal Impact Scenarios2026-26-00021/16/2026
Occupant Safety systems are usually developed using anthropomorphic test devices (ATDs), such as the Hybrid III, THOR-50M, ES-2, and WorldSID. However, in compliance with NCAP and regulatory guidelines, these ATDs are designed for specific crash scenarios, typically frontal and side impacts involving upright occupants. As vehicles evolve (e.g., autonomous layouts, diverse occupant populations), ATDs are proving increasingly inadequate for capturing real-world injury mechanisms. This has led to the adoption of computational Human Body Models (HBMs), such as the Global Human Body Models Consortium (GHBMC) and Total Human Model for Safety (THUMS), which offer superior anatomical fidelity, variable anthropometry, active muscle behaviour modelling, and improved postural flexibility. HBMs can predict internal injuries that ATDs cannot, making them valuable tools for future vehicle safety development. This study uses a sled CAE simulation environment to analyze the kinematics of the HBMs model in a frontal crash scenario. The methodology includes the initial correlation of Hybrid III CAE simulation results with physical sled test data, followed by a comparative analysis with GHBMC M50-O v6-2 based simulations. A significant difference was observed in pelvic forward displacement between the Hybrid III and GHBMC M50-O v6-2. The difference in interaction originates from the difference in the construction of the pelvis between the Hybrid III and GHBMC. In the GHBMC, reduced displacement occurs because the pelvis locks in the seat. This interaction is absent in ATDs, resulting in increased torso rotation and a potential rise in upper extremity injury risk for HBMs. The study examines the various reasons for pelvic locking and increased upper body rotation. These evaluations aim to raise the negative consequences of pelvic locking on upper extremity injuries. The probable solutions that can reduce pelvis locking while preserving occupant stability is also discussed. The study highlights the significance of HBMs in understanding occupant interactions and supports their use in the development of next-generation restraint systems.
Raj, Pavan, Rao, Guruprakash, Pendurthi, Chaitanya Sagar, Nehe, Vaibhav, Chavan, Avinash
Enhancing Energy Absorption in Rear Impact Events through Rail Extension Design and Material Variations2025-36-009612/18/2025
Safety improvements in vehicle crashworthiness remain a primary concern for automotive manufacturers due to the increasing complexity of traffic and the rising number of vehicles on roads globally. Enhancing structural integrity and energy absorption capabilities during collisions is paramount for passenger protection. In this context, longitudinal rails play a critical role in vehicle crashworthiness, particularly in mitigating the effects of rear collisions. This study evaluates the structural performance of a rear longitudinal rail extender, characterized by a U-shaped, asymmetric cross-section, subjected to rear-impact scenarios. Seventy-two finite-element models were systematically developed from a baseline configuration, exploring variations in material yield conditions, sheet thickness, and targeted geometric modifications, including deformation initiators at three distinct positions or maintaining the original geometry. Each model was simulated according to ECE R32 regulation standards, ensuring validity and compliance with relevant safety criteria. Specific energy absorption (SEA), load uniformity, and structural acceleration were used as key measures of crashworthiness. Simulation outcomes indicated that reductions in thickness significantly increased SEA due to enhanced deformability. Thinner configurations demonstrated greater energy absorption and improved load uniformity, whereas thicker components increased structural rigidity, resulting in decreased energy absorption and higher accelerations transmitted to the vehicle’s B-pillar. Material properties had moderate influence, with higher-strength materials elevating accelerations. Geometric modifications, particularly deformation initiators at specific positions, substantially improved SEA, achieving enhancements up to 42% compared to baseline. These findings highlight the potential of strategic adjustments in geometry, material selection, and thickness to significantly enhance vehicle crashworthiness and occupant safety.
Souza Coelho Freitas, Victor de, Pereira, Romulo Franco, Souza, Daniel Souto de
Impact of Harness Integrated Crash RestraintsF-0081-2025-02705/20/2025
The Crashworthy and Escape Systems Branch at NAWCAD has been developing an integrated restraint harness concept for several years, with the intent of developing a novel method of providing improved occupant protection in a crash scenario. A series of tests was conducted on the Horizontal Accelerator at NAS Patuxent River to evaluate the performance of the prototype integrated-restraint system under MIL-STD-58095 conditions with the 50th percentile male Hybrid III Anthropomorphic Test Device (ATD). While occupant flail was the primary metric being analyzed in this effort, ATD instrumentation was also captured, showing that the integrated restraint system demonstrated a significant reduction in head flail compared to five-point restraints while maintaining injury criteria within acceptable levels.
Anderson, Eric, Minnich, Shannon
Evaluation of Occupant Injury Risk in a Transport Aircraft Crash Test Environment02-18-02-00115/16/2025
Researchers at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) previously conducted a full-scale crash test of a Fokker F28 MK1000 aircraft to study occupant injury risks. The goal of the current study was to investigate the injury predictions of the Global Human Body Models Consortium (GHBMC) and Total Human Model for Safety (THUMS) occupant models in the tested aircraft crash condition and explore possible utilization of both human body models (HBMs) in this context. Eight crash conditions were simulated utilizing each of the models. The HBMs were positioned in two postures, a neutral upright posture with hands resting on the legs and feet contacting the floor and a braced posture with head and hand contact with the forward seat back. Head and neck injury metrics and lumbar vertebra axial force were calculated and compared for all simulations. Both HBMs reported similar kinematic responses in the simulated impact conditions. However, the GHBMC model reported higher forces and injury risks in almost all scenarios. The HBMs were compared to previously modeled anthropomorphic test device (ATD) response. The HBMs showed higher loading than the modeled ATDs in two out of eight impact conditions. Relative to the THUMS model, the GHBMC model had included more virtual instrumentation and produced injury metric values, which encompassed that of the THUMS model. The THUMS model has additional value in being a free access model. Both models provided valuable insight into the potential response of the human body within the simulated aerospace crash environment.
Jones, Nathaniel, Putnam, Jacob, Untaroiu, Costin Daniel
Overview of Seat Design Changes and Performance2025-01-87294/1/2025
The National Highway Traffic Safety Administration (NHTSA) published an Advance Notice of Proposed Rulemaking (ANPRM) to update the Federal Motor Vehicle Safety Standard (FMVSS) 207. Part of the ANPRM is to assess the merit of conducting quasi static body block seat pull tests and conducting FMVSS 301 rear crash tests at 80 km/h or higher with a 95th percentile ATD lap-shoulder belted in the front seats and limiting seatback deflection to 15 to 25 degrees. Prior to updating regulations, it is important to understand the seating design history and implications. This study was conducted to provide a historical background on seat design and performance using literature and test data. One objective was to first define the terminology used to describe occupant kinematics in rear crashes. Secondly, seat design evolution is then discussed. Third, test methods and test results were summarized, and fourth, the field performance are synopsized and discussed with respect to 2nd row occupant protection. Seat design evolution: Seat designs have continuously evolved for the last 70 years, including changes in seat structure and seat/head restraint geometry. Over the past decades, seatbacks have become taller and include open perimeter frames and dual recliners. Head restraints have become larger and/or more forward. Seat properties have also changed over time, resulting in better performance. These changes resulted in an increase in strength. The changes in design and properties allow the occupant to pocket while offering load-limiting and controlled head and neck support. Test method summary: Various methods are used to evaluate seat performance, including quasi-static pull tests and dynamic sled tests. Pull tests include applying a rearward load at the upper cross member of the seatback frame, which does not account for the interaction between the occupant and the seat. Other test methods include using a body block as suggested in the ANPRM. Many tests have been conducted with the body block representative of the upper torso geometry and center of gravity (cg) of a 50th percentile occupant. The data show a continuous increase in rearward loading strength, averaging 1,232 Nm (10,902 in-lbs) in seats with model year (MY) 1989 and older and 3,244 Nm (28,716 in-lbs) in MY 2010+, decreasing dynamic seatback rotation. FRED (Ford Rear-Impact Energy Device) is another type of device used in pull testing. FRED provides a more biofidelic test for occupant loading and interaction with the seat; the load location coincides with the cg of a 50th percentile occupant. However, there is less FRED data available for historical comparisons. Sled tests are conducted at low-to-moderate speeds and at high-speed. For example, low-to-moderate speed sled tests are conducted at 16 km/h as part of the Insurance Institute Highway Safety (IIHS) head restraint evaluation program, terminated in 2022, and at 17.3 km/h as part of FMVSS 202a. Testing and field performance: The result of this study suggests that the newer seat designs are performing well. Modern seats (2010+ MY) exceed the FMVSS 207 static strength requirement by a factor greater than 8 on average. Dynamic sled tests, conducted with the BioRID and with the 50th Hybrid III, show good performance. The occupant biomechanical responses obtained from 40 km/h rear sled tests remain well below injury thresholds. There was a decrease in neck extension. Chest g’s 3ms however remined similar irrespective of MY group; it averaged 14.6 ± 4.6g with 1990-1999 MY- and 15.7 ± 2.4g in 2010+ MY seats. In either the earlier or more recent MY vehicles, these peak chest accelerations occurred prior to maximum seatback deflection. Conclusion: These results of this study provide background for consideration of future test requirements. Overall, conducting dynamic sled tests with a FMVSS 301R impact energy and 50th percentile male ATD may be valuable. However, selecting a maximum dynamic deflection limit would require additional work, as it may affect seat yielding performance. Yielding is beneficial for overall crash safety, particularly for older and/or more vulnerable occupants. Protecting rear seat occupants from front seat interaction may be the reasoning behind limiting the seatback deflection. Care must be taken in understanding the cause of injury risk to rear occupants when considering design changes that may influence the risk to front seat occupants, especially since the front seats are occupied at a higher rate than rear seats. For example, the literature review indicates that factors outside of front seat design such as intrusion were a significant factor on second-row occupant injury outcomes. The size of the BioRID and 50th Hybrid III used in sled testing is representative of an average driver involved in tow-away crashes. Conducting tests with 95th percentile ATD may thus bias the data and could have unintended consequences for smaller or vulnerable occupants.
Parenteau, Chantal, Burnett, Roger, Davidson, Russell
Analysis of the Event Data Recorder Vehicle System Data of a GM Vehicle Intelligence Platform Airbag Control Module (SDM50)2025-01-87144/1/2025
The primary function of an Airbag Control Module (ACM), referred to as the Sensing and Diagnostic Module (SDM) by General Motors (GM), is to detect crashes, discriminate crashes, evaluate crash severities, deploy the appropriate restraints, including airbags and pretensioners, and perform system diagnostics. A secondary function of the SDM is to act as an Event Data Recorder (EDR) which records data during the time periods just prior to (pre-crash) and during a crash event. This data consists of restraint and vehicle system data which is collected, processed, and stored in the EDR. Data stored in the EDR is intended to be retrieved after a crash. This data provides operational information on the vehicle’s occupant protection system and other vehicle systems to assess system performance, aid in crash reconstruction, and support improved vehicle safety. A series of vehicle test maneuvers were conducted while injecting a non-deployment crash pulse directly into the SDM to cause the SDM to record an event with related restraint and vehicle system (pre-crash) data. These tests include a variety of constant speed, acceleration, braking, and steering maneuvers. During these maneuvers, vehicle system data was recorded directly from the serial data bus using a passive monitoring tool, tapped sensors, video cameras, and independent onboard instrumentation and that data was compared with the data recorded within the SDM EDR. This paper addresses the operation and accuracy of the vehicle system data recorded for a crash event by the SDM, specifically the SDM50 and its utilization of the GM Vehicle Intelligence Platform (VIP) vehicle serial communication bus. Evaluation of this data provides an understanding of the accuracy of the vehicle system data recorded for a crash event by the SDM.
Smyth, Brian, Crosby, Charles L, Bickhaus, Ryan, Smith, James, Edmunds, Dustin, Floyd, Donald, Modi, Vipul, Outlaw, RaShawndra D., Wright, Jeff
Analysis of Occupants' Responses in Frontal Sled Tests under a Reclined Rigid Seat Environment2025-01-87344/1/2025
With the increasing adoption of Zero-Gravity Seats in intelligent cockpits, there is a growing concern over the safety of occupants in reclined postures during collisions. The newly released anthropomorphic test device (ATD), THOR-AV, has modified the neck, spine, and pelvis structures to better match reclined postures. This study aims to investigate the changes in kinematic response and injury metrics for occupants in reclined postures, through high-speed frontal sled tests utilizing the THOR-AV. The tests were conducted using an adjustable rigid seat with a zero-gravity characteristic and an integrated three-point seat belt. Six tests were performed across four seat configurations: Standard, Semi-Reclined, Reclined, and Zero-gravity postures. The input acceleration pulse for these tests was derived from the equivalent double trapezoidal waveform of the Mobile Progressive Deformable Barrier (MPDB) test. Data from sensors and high-speed video were collected for analysis. The results indicated that with an increasing seat back angle, the degree of head flexion relative to the torso and neck load increased, with abnormal contact between the shoulder belt and neck. After posture reclining, the forward displacement of the ATD's torso increased, with a concomitant increase in lower chest compression, a decrease in thoracic forces, and a significant rise in lumbar axial forces. The zero-gravity posture exhibited submarining, as inferred from the iliac force reduction rate and video analysis. These findings provide critical insights for optimizing occupant restraint systems in reclined postures. Furthermore, the simplified rigid seat sled test environment demonstrated in this study is conducive to modeling and validation, suggesting the potential for further simulation-based investigations.
Wang, Qiang, Liu, Yu, Fei, Jing, Yang, Xiaoting, Wang, Peifeng, Bai, Zhonghao
A Chronology of Research and Events to-Date Significant to Occupant Protection in Rear-End Automobile Impacts2025-01-87254/1/2025
Theory and principles of occupant protection for automobiles in rear-end collisions have experienced significant evolution over the decades. Performance of the seatback, specifically the stiffness of the structure, during such a collision has been a subject of particular interest and debate among design engineers, accident reconstruction experts, critics, etc. The majority of current seat designs rely on plastic deformation of the seatback structure to protect the occupant from the dynamics of the crash. In attempt to highlight and provide background information for understanding this subject, this work highlights significant events, research, and publications over the past five decades to illustrate how this subject, automobile design, government regulation and public opinion has evolved. It is observed that technology and design for improving rear-impact protection has received less attention than collisions of other principal directions of force. The different types of Anthropometric Test Devices (ATDs) used in research are quantified. Lessons may be learned by design engineers to ensure seatback safety moves forward with progress to improve future generations of automobile seats. It is also observed that the quantity of published works could be influenced by historical events as well as certain research topics trending in the automotive industry.
Warner, Wyatt
The Influence of Reclined Seatback Angles on Occupant Injury Risks in Frontal Impacts2025-01-87324/1/2025
The reclined seatbacks will be increasingly used with the advanced technologies of the intelligent automobile. The occupant collision protection must rise to the challenge facing to the new impact scenarios. It is necessary to understand the injury mechanisms of the reclined occupants in order to design the resistant system and testing protection regulations. In this study, simulation tests were conducted for the Frontal Full Width Impact (FRB) and the Mobile Progressive Deformable Barrier Frontal Impact (MPDB) as specified in the China New Car Assessment Programme (C-NCAP, 2021 version). The simulation used the biomechanical model of the 5th female occupant exhibiting the detailed anatomical structures and a seat model with large-angle seatback. The occupant injury risks and mechanisms with 25°, 45° and 60° seating postures were investigated by analyzing the kinematic and biomechanical parameters, and the influence of the seatback angle on occupant injury was discussed. The results indicate that reclined seatback significantly affects the kinematic responses of the head and neck, with head and neck injuries acting as primary contributors to C-NCAP score reductions. Seatback angle and collision type are key factors influencing the risk of visceral and lumbar spine injuries. In FRB impact condition, the risk of visceral injury reduces by 18% and 17% with the increasing seatback angle, respectively, while the risk of lumbar spine injury decreases by 1% and increases by 38%. In MPDB impact condition, the risk of visceral injury reduces by 28% and 32% with increasing seatback angle, and increases the risk of lumbar spine injury by 51% and 32%, respectively. In conclusion, the head, neck, and visceral organs are common injury regions for occupants in reclined seatbacks, and the collision types influence the injury mechanisms. Mitigating the range of head and neck motion and the compressive forces on visceral organs are critical for protecting reclined posture occupants. These findings from this study could contribute significantly to the development of regulations and restraint systems for reclined occupant protection.
Wang, Yanxin, Pan, Ruyang, Lin, Yuyang, Liu, Yutao, He, Lijuan, Wang, Zhenqiang, zhu, he, Liu, Chong, Li, Kun, Lv, Wenle
Exploring Hybrid TPMS Designs for Improved Energy Absorption2025-01-87264/1/2025
Triply Periodic Minimal Surface (TPMS) structures have gained significant attention in recent years due to their excellent mechanical properties, lightweight characteristics, and potential for energy absorption in various engineering applications, particularly in automotive safety. This study explores the design, manufacturing, and mechanical performance of both general and hybrid TPMS structures for energy absorption. Three types of fundamental TPMS unit cells—Primitive, Gyroid, and IWP—were modeled using implicit functions and combined to form hybrid structures. The hybrid designs were optimized by employing Sigmoid functions to achieve smooth transitions between different unit cells. The TPMS structures were fabricated using Selective Laser Melting (SLM) technology with 316L stainless steel and subjected to quasi-static compression tests. Numerical simulations were conducted using finite element methods to verify the experimental results. The findings indicate that hybrid TPMS structures exhibit superior energy absorption characteristics compared to individual unit cells, with notable improvements in specific energy absorption and structural stability under compressive loads. Furthermore, this study demonstrates the potential application of hybrid TPMS structures in automotive crash box, offering enhanced crashworthiness and multi-stage energy regulation.
Liu, Zhe, Wang, MingJie, Guo, Pengbo, Li, Youguang, Lian, Yuehui, Zhong, Gaoshuo
Load Cell Data Analysis from Frontal NCAP Tests to Assess Aggressivity and Compatibility of Battery Electric and Internal Combustion Engine Vehicles2025-01-87464/1/2025
A total of 368 frontal New Car Assessment Program (NCAP) tests (including 24 tests with Battery Electric Vehicles (BEVs)) with high-resolution load cell data were analyzed to investigate vehicle crash compatibility, especially between Internal Combustion Engine Vehicles (ICEVs) and BEVs. An Indirect Frontal Crash Model (IFCM) for Full-Overlap (FO) Vehicle-to-Moving Deformable Barrier (V2MDB) using load cell data from frontal NCAP tests was developed to assess vehicle aggressivity. An analytical solution of the IFCM for FO/V2MDB was obtained and used to develop a new aggressivity metric. In addition, the Max. Standard Deviation (SD) of load cell forces was used to assess vehicle front-end homogeneity. In the case studies, vehicle compatibility was assessed by the new aggressivity metric and Max. SD, along with typical frontal crash metrics.
Park, Chung-Kyu
Development and Validation of a Rear Head Surround Foam Performance Specification for Stock Car Racing2025-01-83534/1/2025
Over the last two decades many improvements have been made in stock car racing driver safety. One of these is the head surround, which is rigidly secured to and an integral part of the NASCAR (National Association for Stock Car Auto Racing, LLC) seating environment and serves as an effective restraint for head protection during lateral and rear impacts. However, previous head impact material specifications were optimized for moderate to severe impacts and did not address low severity impacts that occur frequently during typical driving, such as race restart vehicle nose-to-tail contact. This study focused on developing a test methodology for comprehensive evaluation of rear head surround materials for low, moderate and severe impacts. Specifically, this study aimed to formulate a specification that maintains previous material performance during high speed impacts, while decreasing head accelerations at low speed impacts. Quasi-static and dynamic drop tower testing of sample materials were used to analyze the energy absorption capabilities of various materials. Finite element material models were developed to assess the effects of foam thickness on head kinematics. Anthropomorphic test device (ATD) empirical sled testing was used to analyze material responses in the full NASCAR seating environment. In drop tower testing, the new materials achieved nearly a 33% reduction in peak acceleration for 2.2 m/s (5 mph) impacts compared to the baseline materials while maintaining original peak acceleration and rebound velocity performance at 5.8 m/s (13 mph). Empirical sled testing confirmed equal performance to the baseline materials at high velocity, as well as a 5 to 15 G decrease in peak resultant head acceleration at low speed depending on comparison samples. Study findings resulted in updates to the NASCAR rulebook including increasing the minimum thickness of the original rear head surround foam material and the use of the newly specified alternate foam materials in the field. The alternate foams drop test requirements include 24 total drop tests on 12 test samples per material evaluation, at two speeds (2.2 and 5.8 m/s) and two temperatures (21° and 50° C). The repeated impacts are conducted at the same test speed, for each temperature, on the same sample. Material performance evaluations include peak acceleration, maximum rebound velocity, and flame retardancy.
Gray, Alexandra N., Harper, Matthew G., Mukherjee, Sayak, Patalak, John P., Gaewsky, James
Application of 1.7GPa Martensitic Steel in Dash Lower Cross Member to Enhance Automotive Frontal Impact Safety2025-01-82184/1/2025
The rapid growth of electric vehicles (EVs) has led to a significant increase in vehicle mass due to the integration of large and heavy battery systems. This increase in mass has raised concerns about collision energy and the associated risks, particularly in high-speed impacts. As a consequence, crashworthiness evaluations, especially front-impact regulations, have become increasingly stringent. Crash speed between the vehicle and the Mobile Progressive Deformable Barrier (MPDB) is increasing, reflecting the growing emphasis on safety in the automotive industry. Moreover, a new frontal pole crash scenario is under consideration for future regulatory standards, highlighting the continuous evolution of crash testing protocols. To ensure occupant protection and battery safety, manufacturers have traditionally used Hot Blow Forming technology for producing closed-loop dash lower cross member components. However, this process is both costly and energy-intensive, necessitating more efficient alternatives. This study explores the development of a closed-loop dash lower cross member using 1.7GPa Cold Rolled Martensitic steel, produced through roll forming and CNC bending. The research addresses critical material aspects, including comprehensive hydrogen embrittlement analysis to evaluate the material’s long-term durability and safety. Furthermore, the study focuses on the crash performance of the closed-loop cross-sectional dimensions 1.7GPa steel grades components. The findings of this study aim to contribute to the design of safer and more efficient structural components for modern EVs, meeting both regulatory requirements and industry needs.
Lee, Jongmin, Kim, Donghyun, Jang, Minho, Kim, Geunho, Seongho, Yoo, Kim, Kyu-Rae
Examination of the Data Structures of the Bendix® Data Recorder2025-01-87124/1/2025
Bendix® EC-80™ and certain EC-60™ ABS control units contain an event data recorder called the Bendix® Data Recorder (BDR). Raw BDR data is obtained using commercially available software, however, the translation of the raw data into an event report has only been performed by the manufacturer. In this paper, the raw data structures of the commercially available datasets are examined. It is demonstrated that the data follows uniform and repeatable patterns. The raw BDR data is converted into a conventional report and then validated against translation reports performed by the manufacturer. The techniques outlined in this research allow investigators to access and analyze BDR records independently of the manufacturer and in a way previously not possible.
DiSogra, Matthew, Hirsch, Jeffrey, Yeakley, Adam
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