Investigation of chest injury mechanism caused by different seatbelt loads in frontal impact.

PURPOSE The purpose of this quantitative study is to investigate the differences of the injury mechanism caused by two different types of seatbelt loads on the occupant's chest. METHODS The finite element analysis is employed to compare the different responses of the human body model, including comparison of kinematics, chest accelerations, seatbelt forces and chest injury outcomes regarding chest deflections and rib fractures. RESULTS The calculated rib strain-stress response from simulations in force-limiting seatbelt are higher than that in the regular seatbelt. The forward movement and torso twist are both great in simulations with force-limiting seatbelt. Moreover, there are obvious differences in the injury outcomes of chest deflections and rib fracture risks under the different seatbelt loads. CONCLUSION Results indicate that the chest deflections and rib fracture risks are negatively correlated under the load of the force-limiting seatbelt, However, they are positively correlated to and determined by the seatbelt peak load of the regular seatbelt. This paper can provide a reference for study of the chest injury mechanism and protection efficiency of seatbelt.