Friction force inherently exists as a nonlinear factor in a vehicle seat suspension. This study tries to address the effect of the friction on the seat suspension's transmission characteristics quantitatively. A nonlinear seat model of two degrees of freedom is established and verified by experiments. A preliminary analysis on the effect is conducted analytically based on the verified model, and a friction factor is defined to describe the extent of nonlinearity introduced by the friction quantitatively. A series of simulations are then carried out to investigate the coupling effects of the friction with various other factors on the transmission characteristics. These factors include load mass, suspension damping, and excitation amplitude. With the simulation results, these coupling effects are explained in terms of the defined friction factor. It is suggested for the targeted vehicles that the friction coefficient should be less than 0.4 so as to have better seat comfort.

Friction force,Seat experiment,Seat transmission characteristics,Nonlinear seat model