Analysis Of Energy-Absorbing Sliding Seat Properties For Neck Injury Protection In Rear Impact

This study investigates the overall properties of a sliding seat concept withenergy-absorbing (EA) function for whiplash neck injury protection in rear impact.The sliding seat includes a mechanism to slide backward for a certain distance andunder certain restraint force. The analysis includes performance assessment of thesliding seat in low, medium and high severity rear impact, as well as frontal collisionand rollover. A mechanism of sliding and EA is also designed for implementation inseat rail system. Furthermore, a prototype of sliding seat is designed and evaluated ina slide test.A numerical model that consists of vehicle interior, a seat, a BioRID II dummyand a seatbelt is built to evaluate occupant whiplash neck injury in rear impact. Thesliding and EA mechanism is included in the seat model. A cross design ofexperiments (DOE) is used in a sensitivity analysis of main neck injury parameters toa number of seat design parameters related to whiplash protection. The parametersincluded in the first batch analysis are position and cushion stiffness of seat headrestraint, seatback cushion stiffness, and seat recliner characteristics, which arecommon seat design parameters in the existing whiplash protection countermeasures.In the second batch of analysis, the sliding seat mechanism including the EA restraintforce is added in the DOE study to assess the effect the sliding seat compared to thatof the existing countermeasures. Finally, an optimization is conducted to obtain theoptimal design configurations for the EA sliding seat for rear crashes of differentseverities.The simulation results show that the EA restraint force of sliding seat hassignificant influence on the following neck injury parameters: NIC, Nkm, upper neckshear force, upper neck tension force and T1acceleration. To provide effective neckprotection in rear impact crash, optimal configurations are3-kN EA restraint forcelevel under low and medium severities and6-kN force level under high severity,respectively. In frontal collision and rollover, compared to non-sliding seat, the sliding seat does not have any negative effects on occupant protection. The proposedsliding and EA mechanism can provide relative constant force that meets theconcept’s needs. The slide test results show that the sliding seat could provide a betterneck protection that that of non-sliding seat when using Hybrid III50thdummy undermedium severity rear impact.