Load-limiting in the lap belt reduces injury risks associated with new seating positions

Abstract

The two objectives are to demonstrate technical feasibility for an advanced 3-point seatbelt system incorporating double lap belt pre-tensioning and load-limiting and to evaluate its injury risk reduction relative to that of a 3-point seatbelt without double lap belt load-limiting. Frontal sled tests were conducted at 50 km/h with a Hybrid III 50-percentile male in upright and reclined with the seat in a rearward position. The advanced 3-point seatbelt system satisfied all requirements and all injury risk metrics (from Euro NCAP and additional ones associated with the new seating positions) were reduced. In particular, the risk for head-to-thigh contact was substantially reduced. Therefore, the advanced 3-point seatbelt system is technically feasible and conveys substantial benefits. More research is needed to investigate the risk of submarining and sliding off the seat, using a wider range of occupant surrogates and more severe crash pulses.

Keywords:

• Advanced seatbelt
• flexible seating
• frontal restraints
• lap belt load-limiter
• occupant protection

Acknowledgements

The authors want to thank Benny Tholin, Per-Erik Johansson, Sonny Muhoray and Mikael Lindberg all at Autoliv Safety Center in Sweden for executing the sled tests and for their patience when changes were made at the last minute. We would also like to thank Linus Larsson and Nicklas Brunnegård for expertise support in designing the prototype seatbelt systems. Thanks are extended to Dr. F. López-Valdés and Dr. J. Kerrigan for their insightful comments on an earlier version of the manuscript. Finally, the authors would like to thank Dr. K. Mayberry for language revisions. The project is associated to SAFER, the Vehicle and Traffic Safety Centre at Chalmers.

Disclosure statement

The authors are employed at Autoliv Research, located in Vårgårda, Sweden. Autoliv Research is part of Autoliv (www.autoliv.com), a company that develops, manufactures, and sells for example protective safety systems to car manufacturers. Results from this study may impact how Autoliv choose to develop their products.

Additional information

Funding

The work is part of the project 2020-02943 Car Passenger Safety – to the next level. The project received funding from FFI (Strategic Vehicle Research and Innovation), Vinnova (Sweden’s Innovation Agency), the Swedish Transport Administration, the Swedish Energy Agency, and the Swedish vehicle industry.