Development of a new recline mechanism in order to reduce the “whiplash” effect using a virtual model

Abstract

The purpose of this paper is to design a mechanism mounted on the occupant’s seat to control the recline of the backseat in the case of rear-end collisions to reduce the effects of whiplash upon the occupant’s neck and head using a virtual model of an occupant and seat. The design of the system is modeled in SolidWorks and simulated in this software by using the Adams physics model included in SolidWorks. The system will function similarly to a real sled; it is composed of a car’s seat, a multibody occupant and a surface along which the seat may slide. This system will be validated by comparing two real sled tests and a seat normally functioning. Once validated, the mechanism is enabled to make simulations which are conducted to analyze the differences in kinematics of the occupant’s neck and the various key parameters such as head accelerations, contact forces and T1 vertebrae acceleration. The multibody occupant is composed of multiple bodies inter-connected with joints and it will simulate a real occupant. As for the evaluation of injury potential for the neck, the neck injury criteria (NIC) are calculated for the comparisons of the two situations: when the backseat has normal rigidity and when the recline mechanism is activated. It was observed that, by using this recline mechanism, the key parameters were reduced. This paper presents the new developed mechanism with the obtained parameter reductions.