A vehicle seat design concept for reducing whiplash injury risk in low-speed rear impact

To reduce whiplash injury risk in low-speed rear-impact accidents, a sliding mechanism of vehicle seat with crash energy-absorption (EA) function is proposed and analysed in this study. It can reduce relative motion between occupant head and torso under rear impact and lower values of neck injury related parameters such as neck injury criterion (NIC), neck displacement criterion (NDC) and neck forces and moment. A number of parameters of seat structure and countermeasures have great influence on occupant head–neck responses in rear impacts. They include head restraint position, seat recliner characteristic and seatback cushion stiffness, as well as the newly proposed seat sliding characteristic. A numerical model that includes a seat and a BIORID II dummy is used in a parametric study to evaluate effects of whiplash injury risk reduction. The analysis results show that proper combinations of the values of these parameters can mitigate the whiplash injuries and they form the basis of the existing countermeasures such as active head restraint and yielding seat as well as the newly proposed sliding seat. The simulations demonstrate the effectiveness of the sliding seat in whiplash injury reduction. Potential merits of the sliding seat, compared to the existing countermeasures, are also discussed. Furthermore, appropriate structural mechanisms for EA sliding of seat are designed through quasi-static tests and finite element simulations and an implementation is also preliminarily sketched.