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Citation
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Östling M, Eriksson L, Dahlgren M, Forman J. 27th International Technical Conference on the Enhanced Safety of Vehicles (ESV); April 3-6, 2023; Abstract #: 23-0198, pp. 24p. Washington, DC USA: US National Highway Traffic Safety Administration, 2023 open access. |
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Abstract
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27th International Technical Conference on the Enhanced Safety of Vehicles (ESV): Enhanced and Equitable Vehicle Safety for All: Toward the Next 50 Years
https://www-esv.nhtsa.dot.gov/Proceedings/27/27ESV-000198.pdf
For car occupants in Europe, a car-to-HGV (heavy goods vehicle) crash is the third most frequent fatal crash type after single and car-to-car crashes. Within car-to-HGV fatal crashes, frontal head-on crashes are most common. These crashes can result in larger structural deformation of the car or higher velocity changes and accelerations than single or car-to-car crashes typically do. Structural compatibility and energy absorbing structures are prerequisites for good crashworthiness, so also for severe head on car-to-HGV crashes. If the car compartment can be kept intact there is a potential to improve the current stateof-the-art frontal restraint systems to provide the occupant with good protection also in high-severity car-to-HGV crashes. The goal of this study was to identify potential limitations in a state-of-the-art frontal restraint system in high-severity car-to-HGV head-on crashes with an intact compartment and propose improvements to the restraint system to reduce and balance the risk of injury for all body regions. Finite element simulations were performed using a frontal sled interior model with a geometry representing a mid‐ size sedan. The frontal sled model was equipped with the semi-rigid seat, a generic seat consisting of spring-loaded seat and submarining pans, developed to represent the characteristics of a front seat, and a seat integrated belt system consisting of a shoulder belt retractor with a 4 kN load limiter and a 2 kN pretensioner, and a 2 kN lap belt pretensioner. Further, the model was equipped with a driver airbag, a steering wheel, a collapsible steering column, a knee bolster, and a foot support. The model was validated by means of mechanical sled tests using generic 40 and 56 km/h full frontal rigid barrier crash pulses and THOR-50M v1.9. After validation the performance of the restraint system was evaluated with the THOR-50M by implementing crash pulses from two car-to-HGV head-on crashes. For both car-to-HGV crash pulses there were severe strikethroughs of the restraint system. Improved seat stiffness, increased shoulder belt load limiter force, and increased knee bolster energy absorption prevented the strikethroughs and reduced the injury criteria values. However, the injury criteria values were still higher than current NCAP performance limits for most of the body regions. To guide the development of adaptive occupant protection tailored for high severity crashes, injury criteria targets are required. Such targets should be balanced between feasibility and still challenging enough to prompt improvements relative to the current state of risks. Occupant protection in different crash severities is of high priority. The occupant protection system should be designed to be adaptive to the crash, i.e. more compliant in low-severity crashes and stiffer in high-severity crashes. Current occupant restraint systems are most likely capable of the proposed improvements with existing technologies. However, they are currently not designed with the level of adaptivity that this study indicates may be beneficial. More research is needed to develop injury criteria target values for survival in high severity crashes, as well as sensors that distinguish between low-, mid- and high-severity crashes with the purpose to adapt the restraint system thereafter. Östling 2 INTRODUCTION In 2019, about 22,700 road traffic related fatalitie
Language: en |