Development of a nonlinear finite element model for estimating static and dynamic seat cushion characteristics

Commercial vehicle seat cushion coupled with occupant are exposed to dynamic forces due to road roughness and vibration transmitted through the vehicle cabin. The mechanical visco-elastic properties of the seat cushion are crucial and are needed to be investigated for enhancing its performance and comfort under static and dynamic conditions. This study investigates the responses of a commercial vehicle seat cushion by measuring its force-deflection characteristics under different pre-loads and excitations. Additionally, a nonlinear finite element seat cushion model was developed using LS DYNA solver to simulate its response under various loading conditions. The simulation results revealed that the force-deflection characteristics of the seat cushion exhibited significant variation depending on the preload, magnitude and rate of excitation. The dynamic simulations provided a reasonably accurate representation of the measured characteristics, showing good agreement with experimental data. However, small discrepancies were observed, particularly with increasing frequency under different loading conditions. This study marked a preliminary attempt at dynamic simulation of seat cushions and verified the validation of the developed model via experimental data. Future work may focus on refining the model to reduce discrepancies and explore additional factors influencing seat cushion performance.