Effect of increase in weight and stiffness of vehicles on the safety of rear seat occupants

Abstract

In this study, full-scale finite element (FE) simulations have been performed to identify factors affecting the protection of rear seat occupants. An FE model based on the 2001 Ford Taurus was used and coupled with a Hybrid III 5th percentile female dummy model in the rear seat of the vehicle. The dummy model was restrained using a three-point belt system. The effects of changes in the vehicle design, including changes in vehicle weight and stiffness, on injury readings of the rear seat dummy, including head injury criterion (HIC), chest acceleration and Nij, were evaluated. The simulation results were first validated against available test data for a Ford Taurus vehicle and later used for the analysis. The analysis showed that an increase in the stiffness of the vehicle can significantly increase rear seat dummy injury measures. It was shown, for example, that the HIC15 of a rear seat dummy can increase from 478 to 755 between two vehicles with an increase in stiffness from 1000 to 1557 N/mm.

Keywords:

• rear seat occupant
• frontal crash
• stiffness
• finite element modelling
• LS-DYNA
• MADYMO

Acknowledgement

The kind and proficient editorial assistance of Ms. Lilly Nix for this paper is acknowledged and greatly appreciated.