Browse Topic: Restraint systems

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Statistical Assessment of Pretensioner and Load Limiter Effects on the Large Omnidirectional Child ATD Response in Frontal Impacts2026-01-0550To be published on 04/07/2026
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 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 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 (APTS). Statistical evaluation using analysis of variance (ANOVA) and Tukey-Kramer post-hoc tests quantified main and interaction effects. Pretensioners
Khattak, Mohid, Bendig, Colleen, Louden, Allison, Noll, Scott
Effects of Child Anthropometry, Seatback Angle, Seat Rotation Angle, Seatbelt Force Limiting, and Collision Type on Injury Risk of Child Occupants in Highly Automated Vehicles2026-01-0570To be published on 04/07/2026
This study aimed to evaluate the influence of child anthropometry, seat posture (recline and rotation), seatbelt force limiting, and frontal collision scenarios on the kinematic response and injury risk to children in highly automated vehicles. The TUST IBMs 6YO-O model was conducted the frontal collisions in sled tests. This simulation matrix includes five percentiles six-year-old occupants (P3, P25, P50, P75, and P97), three seatback angles (20°, 30°, and 45°), four seat rotation angles (0°, 90°, 180°, and 270°), three seatbelt force limiting (2.6 kN, 3.6 kN, and 4.6 kN), and three collision types. Injury risks were assessed including the child occupant's head, neck, chest/abdomen, and lumbar region in each simulation (n=540). The results indicate that the child anthropometry, the seatback angle, and the seat rotation angle have a significant influence on the motion responses. Statistically significant differences between all the groups within each independent variable category were
Wang, Yanxin, Zhao, Hongqian, Li, Haiyan, He, Lijuan, Cui, Shihai, Lv, Wenle
A study on the injury risk of occupant with different head and neck rotating positions2026-01-0574To be published on 04/07/2026
Drivers obtain road information through head and neck rotation. In order to study the impact of head and neck rotation posture on occupant injury in frontal collision, this paper studies the biomechanical response of occupants with five different head and neck rotation posture under 56 km/h frontal collision based on THUMS human model. Firstly, the kinematic response and head center-of-mass acceleration curves of the dead body and THUMS were compared to verify the validity of the vehicle model. Then, THUMS was adjusted to the standard occupant pose and five different head and neck rotation poses of ±20° and ±40°, and frontal collision simulation was conducted for each of the five poses with or without airbags. The results show that with the increase of head and neck rotation Angle, the risk of neck injury increases while the risk of chest injury decreases. 4 ribs are broken under standard posture, and only 2 ribs are broken when the left rotation of head and neck is 40°. The neck Nij
Li, Dongqiang, jiang, Yejie, Li, Yanyan, Tan, Chun, Jiang, Binhui
Revisiting Rear Seat Safety: Field Evaluations of Relative Injury Risk Across Seating Positions and the Integration of Advanced Rear Seat Belt Systems.2026-01-0561To be published on 04/07/2026
Despite advances in automotive crash avoidance, occupant restraint systems remain crucial in protecting the motoring public. Following decades of improvement in occupant protection, including the development of features such as frontal airbags, collapsable steering columns, and seat belt pretensioners and load limiters for the front seat, the safety of rear seat occupants has recently undergone scrutiny. Studies evaluating rear seat occupant injury risk via field crash data have reported findings of reduced relative safety in the rear seating positions and alluded to rear seat advanced restraints, such as pretensioners and load limiters, as a potential solution. While the pursuit of certain novel technologies has historically improved automotive occupant outcomes, evaluation of these new systems in both controlled laboratory environments and field crashes is necessary to understand potential positive and negative effects of widespread introduction. This study expanded upon prior field
Rapp van Roden, Elizabeth Ann, Miller, Bruce, Pearson, Joseph, Williamson, James, Brown, Thomas
Leveraging Machine Learning for Occupant Body Size Estimation via B-Pillar Seatbelt Systems2026-01-0559To be published on 04/07/2026
Occupant body size in vehicles varies significantly, encompassing differences in height, weight, and overall body composition. Adaptive restraint systems, featuring adjustable parameters such as belt load limiters, steering column load limiters and stroke, seat pan stiffness, and airbag pressure, can offer more equitable protection tailored to individual body sizes. In this study, a test rig modeled after the Volvo XC90 was used to collect data from 47 seated participants. Key seatbelt-related parameters, including D-ring angle, belt payout length, lap belt length, and buckle tension, were measured. These measurements were used to train machine learning models to predict occupant characteristics: height, weight, sitting height. The results demonstrate that low-cost sensors embedded in the seatbelt system can provide sufficiently accurate occupant body size estimations to inform adaptive restraint systems. The prediction errors across both training and test datasets were as follows
Wang, Da, Ahmed, Jawwad, Rowe, Mike, Brase, Dan
Numerical Investigation on Thorax Rib Deflections of 50th Male in Vehicle Side Oblique Pole Impact Using Human Body Model2026-01-0566To be published on 04/07/2026
The WorldSID-50M dummy is an advanced side impact dummy that has been adopted extensively in regulatory testing and third party testing such as Euro-NCAP and C-NCAP. However, with increased testing modalities, excessive upper thorax rib deflection was observed in some vehicle side impact tests. It is believed that interaction between arm and thorax rib causes excessive deflection of upper thorax rib in side oblique pole impact with a large side airbag, which has better protection to the shoulders of an occupant. The objectives of the study was as following: (1) Excessive upper thoracic rib deflection of WorldSID-50M dummy are presented in the side oblique pole crash tests while this observation was not found in side impact tests with the barrier. (2) The effect of the interaction between arm and thorax of a 50th male occupant on upper thorax rib deflection was studied using Human Body Models (HBMs). The study indicates that the interaction between arm and thorax ribs has minor effect
Zhou, DY, Chen, Shaopeng, Yan, Li, Wu, Jing, Liu, Chong, Lv, Xiaojiang, Yang, Heping
Machine Learning based Meta-Analysis of IIHS Moderate Overlap Frontal Crash Test for Rear Seat Occupant Safety Performance2026-01-0579To be published on 04/07/2026
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
Lalwala, Mitesh, Kim, Wonhee, Furton, Lisa, Song, Jay
Evaluating the Effects of Improper Positioning and Unbuckling of a Restraint System on a 10-year-old Child ATD in a Far Side Side-Impact Environment2026-01-0562To be published on 04/07/2026
Five sled tests were performed with a Hybrid III 10-year-old child ATD positioned in the 2nd row left seat of a three row 2006 Sport Utility Vehicle. The sled buck was positioned and accelerated on a Hyge Sled to replicate an intersection side impact collision to the passenger (right) side of the Sport Utility Vehicle. 3 of the 5 tests were performed with a delta-V of 17 mph, with one test performed with a properly restrained ATD and two tests performed with improper restraint positioning. 2 of the 5 tests were performed with a delta-V of 24 mph, and both tests included improper restraint positioning effectively identical to the two 17 mph delta-V tests. The first scenario of improper restraint positioning involved moving the torso belt from the left shoulder, over the head, and onto the right shoulder. The second scenario involved the same belt re-positioning as the first scenario, but additionally disengaged the latch plate from the buckle, essentially creating a condition of seat
Luepke, Peter, Hewett, Natalie, Betts, Kevin, Van Arsdell, William, Weber, Paul, Stankewich, Charles, Miller, Gregory, Watson, Richard, Sochor, Mark
Determining the Deployment Threshold of Active Head Restraints Through Real World Crashes.2026-01-0533To be published on 04/07/2026
Accident reconstructionists often face the challenge of working with limited information when analyzing a collision. For this reason, every piece of data can be valuable. In this study, we are examining whether the deployment of an active head restraint can provide meaningful insight into the severity of a crash. To do this, the authors will use the Crash Investigation Sampling System (CISS) to identify vehicles involved in collisions where investigators noted the presence of active head restraints and where airbag control module data was available. From these cases, the status of the driver and right-front passenger active head restraints will be determined using the provided photographs. By correlating deployment status with crash severity, this study will estimate the likelihood of active head restraint deployment at varying levels of collision severity.
Fix, Ryan, Rutledge, Bradley
Improve Safety Balance between Women and Men in Frontal Crashes through Parametric Human Modeling and Adaptive Design Optimization2025-22-00101/23/2026
Objective: Previous studies have reported disparity in injuries between male and female drivers in the risk of certain types of injuries in frontal crashes that may be due to a myriad of sex-related differences, including body size, shape, anatomy, or sitting posture. The objectives of this study are 1) to use mesh-morphing methods to generate a diverse set of human body models (HBMs) representing a wide range of body sizes and shapes for both sexes, 2) conduct population-based frontal crash simulations, and 3) explore adaptive restraint design strategies that may lead to enhanced safety for the whole population while mitigating potential differences in injury risks between male and female drivers Method: A total of 200 HBMs with a wide range of body sizes and shapes were generated by morphing the THUMS v4.1 midsize male model into geometries predicted by the statistical human geometry models. Ten male and ten female HBMs were selected for population-based simulations. An existing
Sun, Wenbo, Hu, Jingwen, Lin, Yang-Shen, Boyle, Kyle, Reed, Matthew, Sun, Zhaonan, Hallman, Jason
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
Klinich, Kathleen D., Manary, Miriam A., Boyle, Kyle J., Vallier, Tyler, Orton, Nichole R.
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
Kudale, Shailesh, Rao, Guruprakash, wayal, Virendra, Goswami, Tarun
Q-Series Child Dummy FE Model Development and Validation for Child Occupant Safety Assessment in Automotive Crashes2026-26-03901/16/2026
The Ministry of Road Transport and Highways (MoRTH), Government of India, has established BHARAT NCAP to provide a fair, meaningful, and objective assessment of the crash safety performance of cars. This program evaluates vehicles across three key areas, including Child Occupant Protection (COP). A critical component of the COP assessment involves dynamic testing using Q-series child dummies representing a 1½-year-old (Q1.5) and a 3-year-old child (Q3). As per the BHARAT NCAP protocol, these dummies are placed in the second-row outboard seating position within Child Restraint Systems (CRSs) and subjected to two primary dynamic impact tests: Offset Deformable Barrier (ODB) conducted at a speed of 64 km/hr. and Mobile Deformable Barrier (MDB) Side Impact tests conducted at 50 km/hr. The dynamic assessment of these child dummies is primarily focused on the head, neck, and chest regions to evaluate the effectiveness of the CRSs and overall vehicle safety system in protecting young
Khopekar, Maria, Lakshminarayana, Apoorva, Mohan, Pradeep, Kurkuri, Mahendra
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
Pendurthi, Chaitanya Sagar, THANIGAIVEL RAJA, T, Kondala, Hareesh, Sudarshan, B.Sudarshan, Nehe, Vaibhav, Rao, Guruprakash
Packaging the HPTS Airbag in a Second-Row Seat2026-26-00331/16/2026
Seats of modern cars should necessarily meet the regulatory safety norms along with aesthetics and comfort. In the existing passenger cars prevailing across the Indian subcontinent, the measure of safety has been a challenging one. The stringent regulatory norms thereby make the Airbag very promising. In the Automotive industry, safety features are very important, one of the topmost features which falls in this category is airbags. The driver and passenger safety during high impact collisions and sudden crashes is the key objective of airbag. This safety is provided by the airbag with its automatic deployment. The inflatable airbag is engineering in a way to respond very quickly during a collision and furnish necessary cushioning to decrease the impulse and enhance the safety of the passenger. The technology has been practiced widely upon many vehicles' seats. However, the present work highlights a novel approach of packaging the HPTS air bag in second row seat. This Air bag unit is
Buradkar, Rajat, Bose, Karthik, Jadhav, Deepika, Balakrishnan, Gangadharan
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
satija, Anshul, Suryawanshi, Yuvraj, Chavan, Avinash, Rao, Guruprakash
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
Raj, Pavan, Rao, Guruprakash, Pendurthi, Chaitanya Sagar, Nehe, Vaibhav, Chavan, Avinash
Side Crash Pressure Sensor Response Prediction: CPM Approach2026-26-04131/16/2026
Side crashes are generally hazardous because there is no room for large deformation to protect an occupant from the crash forces. A crucial point in side impacts is the rapid intrusion of the side structure into the passenger compartment which need sufficient space between occupants and door trim to enable a proper unfolding of the side airbag. This problem can be alleviated by using the rising air pressure inside the door as an additional input for crash sensing. With improvements in the crash sensor technology, pressure sensors that detect pressure changes in door cavities have been developed recently for vehicle crash safety applications. The crash pulses recorded by the acceleration based crash sensors usually exhibit high frequency and noisy responses. The data obtained from the pressure sensors exhibit lower frequency and less noisy responses. Due to its ability to discriminate crash severities and allow the restraint devices to deploy earlier, the pressure sensor technology has
Bhagat, Milind, Narale, Naganath, Mahajan, Ashutosh, Wayal, Virendra, Jadhav, Swapnil
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
Jaju, Divyan, Kulkarni, Dileep, Mahajan, Rahul
Addressing Safety Belt Discomfort among Female Driving Population through Data Collection and Simulation2026-26-00161/16/2026
The number of female drivers in India is increasing alongside the rapid growth of the Indian automotive industry. A driving comfort survey conducted among female drivers revealed that many of them experienced discomfort when wearing safety belts—while driving and as front-seat passengers. This discomfort is primarily due to a phenomenon referred to as “neck cutting.” The root cause of neck cutting is likely related to vehicle design, which is traditionally based on Anthropometric Test Devices (ATD’s) representing the 5th, 50th & 95th percentile (%tile) of the global population. However, a literature review indicated that the anthropometric dimensions of the Indian populations are generally smaller than those of the global for the respective candidate. To validate the neck-cutting issue, various female candidates were asked to sit in the Driver’s seat for physical measurements trials. Accordingly, methodology was developed to quantify neck cutting parameters objectively. A correlation
Kulkarni, Nachiket A, Chitodkar, Vivek V, Eknath Chopade, Santosh, Mahajan, Rahul, Yamgar, Babasaheb S
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
Joshi, Kedar Shrikant, Gadekar, Ganesh, Date, Atul, Koralla, Sivaprasad
An Innovative Collision Sensing Architecture for Robust Functionality of Safety Restraint Systems in Different Challenging Real World Accident Scenarios2026-26-00171/16/2026
In emerging markets, especially in India and other similar countries, the growing traffic density on the roads leads to different types of accidents, including frontal head-on collisions, rear-end collisions, side-impact collisions, collisions with fixed objects such as electric poles, trees, road guard rails, road dividers, and accidents involving pedestrians, cyclists, and two-wheelers. These accidents could be due to over speeding, distracted driving, violation of traffic rules, and inadequate road infrastructure etc. Providing the necessary safety restraint systems (Airbags and Seat belts) in vehicles and ensuring their robust functionality in different real-world accident scenarios will be challenging for vehicle manufacturers. It is high time to redefine the traditional collision-sensing architecture strategies with a logical approach based on a thorough study of available accident data statistics, types of objects, and scenarios leading to severe accidents. Among these, rear-end
KOVALAM, SUNIL KUMAR
Vehicle Electrical Architecture: A Review of Wiring Harness Routing Optimization Strategies2025-36-013012/18/2025
The modern vehicle electrical architecture consists, on average, of 30 integrated electronic modules (ABS, infotainment, instrument panel, etc.), also known as Electronic Control Units (ECUs), and approximately 300 peripherals such as sensors (collision, temperature, oxygen, position, pressure, etc.) and actuators (window motor, mirror motor, relays, airbag inflator, windshield wiper, etc.). This increase in component integration imposes significant challenges to system installation and design. The interconnection of multiple devices renders harness design an arduous and time-consuming task, especially when conducted manually, resulting in error-prone and suboptimal outcomes. Such a scenario highlights the pressing need for studies on harness routing optimization in the automotive industry. Historically, wiring harness design practices have transitioned from manual approaches to the adoption of advanced computational tools. This methodological transition encompasses the use of various
Ribeiro, Thiago, Reis, Breno, Barreto, Zeus, Galeno, Antônio, Pereira, Marcelo, Ferreira, Fláavio Fabrício V. M.
Study on the Sled Test of Far-Side Test and the Influencing Factors of Dummy Damage2025-99-033112/17/2025
The addition of far-side occupants evaluation conditions in C-NCAP2024 version is an important consideration in the development of passive safety in vehicles. This article conducts analysis and research on key points such as test conditions, test results, and influencing factors. Firstly, introduce the test conditions, methods, and protection evaluation of far-side occupants. Secondly, analyze the distribution of factors such as airbag type, armrest height, test waveform, head offset, and dummy damage in the test data. Finally, analyze the influence of five factors, including airbag type, armrest height, test waveform, test conditions, and belt pre-tightening, on the test results. Analysis has found that the WorldSID 50th dummy’s lower neck MX is prone to exceeding high performance limits, compared to single chamber and double chamber airbags, three chamber airbags provide better protection for far-side occupants; For loading waveforms, the probability of the head being in the orange
He, Yonglong, Gu, Haiming, Guo, Xiaotian, Wang, Jingchen
Quantifying Naturalistic Changes in Occupant Postures in Belt-Positioning Booster Seats Utilizing Pressure Mats2025-22-000812/2/2025
Belt-positioning booster seats (BPBs) help promote proper seat belt fit for children in vehicles. The effectiveness of BPBs depends on occupant posture, which can be influenced by BPB design features. This study aimed to quantitatively describe how children's postures naturally change over time in BPBs, using pressure mats. Thirty children aged 5 to 12 participated in two 30-minute trials using randomly assigned seating configurations. Five configurations were studied by installing two backless BPBs in vehicle captain’s chairs, varying booster profile (high, low, or no BPB) and armrest presence (with or without BPB/vehicle seat armrests). TekScan 5250 pressure mats were placed on the seating surfaces. Children began in an ideal reference posture, and center of force (COF) data were collected continuously. Additional observations on posture, behavior, and comfort were periodically collected. Mixed models, including effects of seating configuration, time, and volunteer characteristics
Connell, Rosalie, Baker, Gretchen H., Mansfield, Julie A.
Enhancing Tipper Stability during Descent with Dynamic Angle Adjustment2025-28-027611/6/2025
Tippers transporting loose bulk cargo during prolonged descents are subject to two critical operational challenges: cargo displacement and rear axle lifting. Uncontrolled cargo movement, often involving loose aggregates or soil, arises due to gravitational forces and insufficient restraint systems. This phenomenon can lead to cabin damage, loss of control, and hazardous discharge of materials onto roadways. Simultaneously, load imbalances during descent can cause rear axle lift, increasing stress on the front steering axle, resulting in tire slippage and compromised maneuverability. This study proposes a dynamic control strategy that adjusts the tipper lift angle in real time to align with the descent angle of the road. By synchronizing the trailer bed angle with the slope of the terrain, the system minimizes cargo instability, maintains rear axle contact, and enhances braking performance, including engine and exhaust braking systems. Computational modelling is employed to assess the
Vijeth, Abhishek, Bhosle, Devidas Ashok, Cherian, Roshni, Dash, Prasanjita
Research and Analysis on Airbag Dangerous Deployment Evaluation Based on 2024 Version C-NCAP2025-99-007310/17/2025
Research on the subjective items of airbag dangerous deployment in the 2024 version of C-NCAP regulations, which includes two aspects: the action of the airbag sweeping over the face and the speed of airbag deployment. This article starts from other aspects. On the one hand, when examining the action of airbags sweeping over the face, it is necessary to consider the acceleration index. Based on the head injury index of the front dummy in collision in C-NCAP, the injury index of face - sweeping risk is defined; On the other hand, the force level of facial injury should also be examined, and the definition and experimental methods should be discussed based on the force level that the head can withstand. Added airbag deployment hazard assessment for the HIII 5 female dummy.
Tian, Wei, Xue, Kaile, Wang, Qinggui
Monitoring the Injection Molding Process to Improve Quality and Lower CostsTBMG-5389710/1/2025
When it comes to plastics applications, cars are rarely the first products that come to mind. However, with modern vehicles containing 1,000 to 1,500 plastic parts — including dashboards, control elements, clips, trim parts, brackets, door panels, bumpers, and radiator grilles — the material is more important for mobility than we might assume. Some of these plastic parts are relevant for the drivers’ safety: for instance, airbag covers must open correctly in an accident and seat belt guides and retractors could cause severe injuries if they break or deform under load. Their quality is vital. At the same time however, cost pressure and new regulations — for instance regarding an increased use of recycled materials that is under way in the European Union — pose new challenges, especially in plastic injection molding. Digital solutions for measurement technology help control and stabilize the complex process and may even lead to increased product quality despite tougher conditions.
Design and Analysis of Passive Controlled Plastic Hinge in Two-Post Rollover Protective Structure for Off-Highway Motor Grader Equipment02-19-01-00017/23/2025
Rollover protective structures (ROPS) that absorb energy during vehicle rollovers play a crucial role in providing integrated passive safety for operators restrained by seat belts. These protective structures, integrated into the vehicle frame, are designed to absorb high-impact energy and deform in a controlled manner without intruding into the occupant’s safe zone. This research focuses on the detailed analytical design procedure and performance evaluation criteria of the two-post open ROPS used on motor graders against lateral loads. An experimental test on a standard tubular square hollow section (SHS) column subjected to lateral load has demonstrated a significant correlation between the post-yield behavior of plastic hinge development and energy absorption, compared with results from various formulations adopted in finite element analysis (FEA). To reduce design iteration time and the cost of physical destructive testing, the complete equipment experimental setup is virtually
J., Avinash
Nonlinear Finite Element Calculation of Ultimate Breakage Load for Pyro-Inflator Housing2025-01-50456/27/2025
Accurate prediction of the ultimate breakage pressure load for pyro-inflator housing is a critical aspect of inflator development. In this study, the tensile test of a specimen, from its initial shape to fracture, is simulated to verify the material properties of the inflator housing. The numerical results demonstrate high accuracy, with the tensile force–displacement curve, maximum tensile force, necking in the concentrated instability zone, fracture location, and inclined angle all closely matching the experimental data. Following material correlation, the ultimate breakage load of the inflator housing under hydrostatic burst test conditions is calculated using an explicit solver. A stress tensor state analysis method is proposed to define the ultimate load based on the onset of plastic instability in the thickness direction at the top center of the inflator. Compared to experimental results, the accuracy of the ultimate breakage pressure prediction using this method is 99.04%, while
Wang, Cheng
Head Accelerations and Concussion Risks in Low-to-Moderate–Speed Rear-End Collisions2025-01-50416/10/2025
Recent studies have investigated head injury metrics, including mild traumatic brain injury (mTBI), or concussion risks, in low- to moderate-speed rear-end collisions, with linear and angular head accelerations contributing to the risk of developing a concussion. The present study analyzes head acceleration values in rear-end collisions at an impact severity of 5–30 km/h delta-V. Biomechanical data was obtained from HIII 50th percentile male anthropomorphic test devices (ATDs) seated in the target subject vehicles and utilizing safety restraints and head rests. Concussion risks were calculated from resultant linear and angular head accelerations recorded in the ATDs, and a linear regression model was used to determine what, if any, relationship existed between these head injury metrics and impact severity. The results indicate that there is a significant and positive relationship between head acceleration metrics and impact severity, particularly in the sagittal plane, with F-values
Garcia, Beatriz, Emanet, Hatice Seyda, Hoffman, Austin
Occupant Restraint and Equipment Mounting Integrity - Rear Impact Ambulance Patient CompartmentJ3044_202505 (Current)5/20/2025
This SAE Recommended Practice describes the test procedures for conducting rear impact occupant restraint and equipment mounting integrity tests for ambulance patient compartment applications. Its purpose is to describe crash pulse characteristics and establish recommended test procedures that will standardize restraint system and equipment mount testing for ambulances. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
Truck Crashworthiness Committee
Occupant Restraint and Equipment Mounting Integrity - Side Impact Ambulance Patient CompartmentJ2956_202505 (Current)5/20/2025
This SAE Recommended Practice describes the test procedures for conducting side impact occupant restraint and equipment mounting integrity tests for ambulance patient compartment applications. Its purpose is to describe crash pulse characteristics and establish recommended test procedures that will standardize restraint system and equipment mounting testing for ambulances. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
Truck Crashworthiness Committee
Structural Strength Evaluation of the Lightweight Frame of Bus Passenger Seat with High-Tensile Material and Analysis of the Importance of Independent Variables by Regression02-18-04-00225/10/2025
This study aims to develop a lightweight bus passenger seat frame by conducting structural nonlinear finite element analysis (FEA) on various thickness combinations of seat frame components to identify the optimal configuration. The thicknesses of critical structural members that primarily bear the load when force is applied to the seat frame were selected as independent variables, while stress on each component and compliance with ECE R14 seatbelt anchorage displacement regulations were set as dependent variables. A regression analysis was performed to calculate the importance of each component and analyze the influence of each design variable on the dependent variables. Strain gauges were attached to critical areas of the actual seat frame to conduct a seatbelt anchorage test, and simulations under identical conditions were performed using the nonlinear FEA software (LS-DYNA) to validate the reliability of the analysis results. The optimized seat frame exhibited a maximum stress of
Ko, Yeong Gook, Cho, Kyu Chun, Lee, Ji Sun, Kang, Ki Weon
The Applications of Acoustic Black Holes to Attenuation of Coach/Bus Frame Structure Vibrations2025-01-00655/5/2025
Basic structures of vehicle frames、aircraft fuselages and ship hulls are made of beams、columns and trusses. If Acoustic Black Holes(ABH) are carefully arranged alongside with the wave propagation paths in those structures, the wave propagation paths could be changed at NVH engineers’ will and the structure vibrations can be reduced. Two kinds of ABHs are used in this paper: one is ABH made of Polyurethane(PU), other one is ABH composed of several steel plate 1D ABH stacked up in parallel. Three structures are used to test the effectiveness of ABHs for vibration reductions: a squared hollow sectional steel commonly used in motorcoach/bus chassis and frame structures, a simple frame for motorcoach airbag suspension and a 12m chassis structure. The attached ABHs show a great vibration attenuation in terms of transfer functions on the basic structure element for a motorcoach. The lateral, vertical and longitudinal transfer functions for steel ABHs were greatly reduced from 13.2~14.7 dB
Xu, Chuanyan, Wang, Jianjun, Xing, Qisen, Chen, Hengbin, Huang, Xianli
Occupant Restraint and Equipment Mounting Integrity - Frontal Impact Ambulance Patient CompartmentJ2917_202505 (Current)5/3/2025
This SAE Recommended Practice describes the test procedures for conducting frontal impact occupant restraint and equipment mounting integrity tests for ambulance patient compartment applications. Its purpose is to describe crash pulse characteristics and establish recommended test procedures that will standardize restraint system and equipment mounting testing for ambulances. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
Truck Crashworthiness Committee
USCAR FRONTAL AIRBAG PERFORMANCE SPECIFICATIONUSCAR52 (Current)4/9/2025
This specification establishes the DV/PV performance and validation requirements for frontal airbag modules, namely driver, passenger, and knee airbags. In cases where airbag designs fall outside the scope of this standard, the Responsible Vehicle Engineering Organization (RVEO) is the final arbiter of all performance requirements within this specification. Additional system level requirements may be introduced by the RVEO but are outside the scope of this specification.
USCAR
Analysis and Comparison of Metrics to Assess Submarining Behavior with the Hybrid III 5th Percentile Dummy in the Rear Seat2025-01-87114/1/2025
Real-world data show that abdominal loading due to a poor pelvis-belt restraint interaction is one of the primary causes of injury in belted rear-seat occupants, highlighting the importance of being able to assess it in crash tests. This study analyzes the phenomenon of submarining using video, time histories, and statistical analysis of data from a Hybrid III 5th female dummy seated in the rear seat of passenger vehicles in moderate overlap frontal crash tests. This study also proposes different metrics that can be used for detecting submarining in full-scale crash tests. The results show that apart from the high-speed videos, when comparing time-series graphs of various metrics, using a combination of iliac and lap belt loads was the most reliable method for detecting submarining. Five metrics from the dynamic sensors (the maximum iliac moment, maximum iliac force drop in 1 ms, time for 80% drop from peak iliac force, maximum pelvis rotation, and lumbar shear force) were all
Jagtap, Sushant R, Jermakian, Jessica S, Edwards, Marcy A
Comprehensive Injury Assessment of Reclined Occupants across Varied Seat Configurations with the THUMS Human Body Model2025-01-87394/1/2025
The development of autonomous driving technology will liberate the space in the car and bring more possibilities of comfortable and diverse sitting postures to passengers, but the collision safety problem cannot be ignored. The aim of this study is to investigate the changes of injury pattern and loading mechanism of occupants under various reclined postures. A highly rotatable rigid seat and an integrated three-point seat belt were used, with a 23g, 50kph input pulse. Firstly, the sled test and simulation using THOR-AV in a reclined posture were conducted, and the sled model was verified effective. Based on the sled model, the latest human body model, THUMS v7, was used for collision simulation. By changing the angle of seatback and seat pan, 5 seat configurations were designed. Through the calculation of the volunteers' pose regression function, the initial position of THUMS body parts in different seat configurations was determined. The responses of human body parts were output
Yang, Xiaoting, Wang, Qiang, Liu, Yu, Fei, Jing, Wang, Peifeng, Li, Zhen, Bai, Zhonghao
The Influence of out-of-Position Displacement during Emergency Braking on Occupant Whiplash Injury in Subsequent Rear-End Collisions2025-01-87204/1/2025
In the pre-crash emergency braking scenario, the occupant inside the vehicle will move forward due to inertia, deviating from the standard upright seating position for which conventional restraint systems are designed. Previous studies have mainly focused on the influence of out-of-position (OOP) displacement on occupant injuries in frontal collisions, and provided solutions such as active pretensioning seatbelts (APS). But little attention has been paid to the influence of OOP on whiplash injury during a subsequent rear-end collision. To investigate the forward OOP impact on whiplash injuries and the effectiveness of APS in this accident scenario, a vehicle interior model with an active human body model (AHBM) was setup in the MADYMO simulation platform. Different braking strengths (0.8g and 1.1g), APS triggering times (from 0.2s before to 0.2s after the braking initiation) and pretensioning forces (from 100N to 600N) were input to the simulation matrix. The occupant’s forward OOP
Fei, Jing, Qiu, Hang, Wang, Peifeng, Liu, Yu, Cheng, James Chih, Zhou, Qing, Tan, Puyuan
Design of an Integrated Crash Safety Test Scenario: Rear-End Collision in SUBSEQUENCE of Emergency Braking2025-01-87474/1/2025
The integrated vehicle crash safety design provides longer pre-crash preparation time and design space for the in-crash occupant protection. However, the occupant’s out-of-position displacement caused by vehicle’s pre-crash emergency braking also poses challenges to the conventional restraint system. Despite the long-term promotion of integrated restraint patterns by the vehicle manufacturers, safety regulations and assessment protocols still basically focus on traditional standard crash scenarios. More integrated crash safety test scenarios and testing methods need to be developed. In this study, a sled test scenario representing a moderate rear-end collision in subsequence of emergency braking was designed and conducted. The bio-fidelity of the BioRID II ATD during the emergency braking phase is preliminarily discussed and validated through comparison with a volunteer test. The final forward out-of-position displacement of the BioRID II ATD falls within the range of volunteer
Fei, Jing, Wang, Peifeng, Qiu, Hang, Liu, Yu, Shen, Jiajie, Cheng, James Chih, Zhou, Qing, Tan, Puyuan
Assessment of Injuries in Rear Impacts2025-01-87274/1/2025
Rear impacts make up a significant portion of crashes in the United States. To date, regulations on rear impacts have focused on fuel system integrity and seat performance, while most research has focused on seat performance in relation to occupants’ injuries, with some analyses of crash severity and seat belt effects. The performance of seats and seat belts may vary depending on the size of the occupant. Understanding how occupant characteristics, as well as crash scenarios, affect injury outcomes can show opportunities for further enhancements in rear impact occupant protection. This paper presents analyses using survey weighted logistic regression models to understand the factors affecting serious injury outcomes (i.e., MAIS 3+) in rear impacts, exploring the potential for improving occupant outcomes. Three separate models are evaluated, focusing on 1) overall injury level, 2) head, neck, and cervical-spine injuries, and 3) thorax, abdomen, thoracic- and lumbar-spine injuries for
Greib, Joshua, Jurkiw, Renee, Kryzaniwskyj, Tanja, Owen, Susan, Van Rooyen, Paul, Whelan, Stacey, Williamson, John
Machine Learning-Enabled Optimization of Vehicle Restraint Systems – Demonstration in a Real-World Crash Scenario2025-01-87224/1/2025
Vehicle restraint systems, such as seat belts and airbags, play a crucial role in managing crash energy and protecting occupants during vehicle crashes. Designing an effective restraint system for a diverse population is a complex task. This study demonstrates the practical implementation of state-of-the-art Machine Learning (ML) techniques to optimize vehicle restraint systems and improve occupant safety. An ML-based surrogate model was developed using a small Design of Experiments (DOE) dataset from finite element human body model simulations and was employed to optimize a vehicle restraint system. The performance of the ML-optimized restraint system was compared to the baseline design in a real-world crash scenario. The ML-based optimization showed potential for further enhancement in occupant safety over the baseline design, specifically for small-female occupant. The optimized design reduced the joint injury probability for small female passenger from 0.274 to 0.224 in the US NCAP
Lalwala, Mitesh, Lin, Chin-Hsu, Desai, Megha, Rao, Shishir
Literature Review and Framework for Identifying Seat Belt Misuse and Misrouting in Frontal Collisions2025-01-87214/1/2025
The effect of seat belt misuse and/or misrouting is important to consider because it can influence occupant kinematics, reduce restraint effectiveness, and increase injury risk. As new seatbelt technologies are introduced, it is important to understand the prevalence of seatbelt misuse. This type of information is scarce due to limitations in available field data coding, such as in NASS-CDS and FARS. One explanation may be partially due to assessment complexity in identifying misuse and/or misrouting. An objective of this study was to first identify types of lap-shoulder belt misuse/misrouting and associated injury patterns from a literature review. Nine belt misuse/misrouting scenarios were identified including shoulder belt only, lap belt only, or shoulder belt under the arm, for example, while belt misrouting included lap belt on the abdomen, shoulder belt above the breasts, or shoulder belt on the neck. Next, the literature review identified various methods used to assess misuse
Gu, Emily, Parenteau, Chantal
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
Wang, Qiang, Liu, Yu, Fei, Jing, Yang, Xiaoting, Wang, Peifeng, Bai, Zhonghao
Effects of Aging on PVC-Based Instrument Panel Skin for Passenger Airbag Deployment Analysis2025-01-83214/1/2025
Plasticized polyvinyl chloride (PVC) has many applications in automotive industry including electrical harnesses, door handles, seat and head rest covers, and instrument panel (IP) and other interior trim. In IP applications, the PVC skin plays a critical role in passenger airbag deployment (PAB) by tearing along the scored edge of the PAB door and allowing the door to open and the airbag to inflate to protect the occupant. As part of the IP, the PVC skin may be exposed to elevated temperatures and ultraviolet (UV) radiation during the years of the vehicle life cycle which can affect the PVC material properties over time and potentially influence the kinematics of the airbag deployment. Chemical and thermal aging of plasticized PVC materials have been studied in the past, yet no information is found on how the aging affects mechanical properties at high rates of loading typical for airbag deployment events. This paper compares mechanical properties of the virgin PVC-based IP skin
G, Karthigan, Savic, Vesna, Ravichandran, Gowrishankar
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
Smyth, Brian, Crosby, Charles L, Bickhaus, Ryan, Smith, James, Edmunds, Dustin, Floyd, Donald, Modi, Vipul, Outlaw, RaShawndra D., Wright, Jeff
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
Wang, Yanxin, Pan, Ruyang, Lin, Yuyang, Liu, Yutao, He, Lijuan, Wang, Zhenqiang, zhu, he, Liu, Chong, Li, Kun, Lv, Wenle
A Sled Test Methodology for 25% Offset Crash Tests2025-01-87374/1/2025
Sled crash tests are an important tool to develop automotive restraint systems. Compared with full-scale crash tests, the sled test has a shorter development cycle of the restraint system and lower cost. The objective of the present study is to create a cost-effective sled test methodology, calculate the optimal static yaw angle and loading curves, and analyze the motion response and injuries of the dummy in the small overlap crash test. The effectiveness of the proposed methodology was verified under two typical small overlap frontal crash modes: “energy-absorption” and “sideswipe”. The results show that with the calculated yaw angle α, the HIC was different from the small overlap crash model, but all remaining indices were within 5% of the injury criteria. All International Organization for Standardization (ISO) values between the combined accelerations of all parts of the dummy and those of the basic model exceeded 0.75, and some values were above 0.8. Therefore, the proposed sled
Yu, Liu, Chen, Jianzhuo, Wan, Ming Xin, Fan, Tiqiang, Yang, Peilong, Nie, Zhenlong, Ren, Lihai, Cheng, James Chih
Headliner Design Considerations to Meet Safety and Regulations2025-01-82454/1/2025
Headliners are one of the largest components inside an automobile, stretching from the front windshield to the rear windshield. Besides its aesthetic purpose, it contributes to multiple other purposes like housing different components, helps in NVH, defines the interior roominess, and plays a crucial role in defining the deployment of curtain airbag. The headliner also plays a role in meeting regulatory requirements like upward visibility and headroom requirements of the occupants. During the deployment of curtain airbag, it is important that the headliner-pillar interface aids in the easy opening of airbag, with the least hindrance. This is defined by multiple factors like the location of headliner-pillar interface, its distance from the airbag ramp bracket, the position of the inflator, the mountings of the headliner and pillar trims, to name a few. Also, during the deployment of the airbag, it is important that parts such as grabhandle, speaker grilles, etc which are fitted on the
Sabesan, Arvind Kochi, D., Anantha, Kakani, Phani Kumar
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