Abstract:The response of single degree of freedom (DOF) of vehicle suspension with nonlinear hysteresis characteristics under the bounded noise excitation was studied. In order to achieve the critical condition of chaotic motion of the system, the stochastic Melnikov process of system subjected to two co bounded noise excitations was derived. Then, an analysis was made of the influence of suspension hysteresis parameters on the chaotic motion. By using the Poincaré section, power spectrum and the largest Lyapunov exponent, the chaotic motion of system was verified numerically. The results show that, chaotic motion exists in the hysteretic nonlinear suspension system is subjected to two co bounded noise excitations, and it is found that when the amplitude of bounded noise excitation is small, the system does not appear chaotic motion; while the amplitude is large, chaotic motion possibly occurs.