Investigation of chest biomechanical response by variation of restraint loads in frontal impact

The seatbelt restraint load is one of the primary sources of occupant chest injury. Thus, studying the different biomechanical responses of chest by varying the seatbelt loads will result in a significant improvement in seatbelt protection performance. Based on the high-biofidelity mechanical dummy model, a sled-dummy test was conducted to investigate the differences in chest injury outcomes caused by the variation of seatbelt load paths or load processes. The chest kinematics and kinetics are compared to determine the influence of load factors on these biomechanical outcomes. Results show that chest injury severity has a positive nonlinear correlation with impact speed. However, the injury risk is mainly determined by the seatbelt peak load in the chest deflection analysis. The results of this study can provide a reference to seatbelt safety design and optimization. The model and method can be used in other research works on the biomechanics of frontal impact.