随机激励下汽车非线性悬架系统的混沌研究

摘要

研究了具有迟滞非线性特性的单自由度悬架模型在随机激励下的混沌运动。运用随机梅尔尼科夫（Melnikov）方法，推导并得到有界噪声激励下系统在均方意义下发生混沌运动的临界条件，讨论了悬架迟滞参数对系统混沌运动的影响，并运用庞加莱截面、功率谱和最大李雅普诺夫指数（LLE ）进行了数值验证，研究表明，悬架系统存在混沌运动。分析了C级路面激励下，汽车单自由度悬架迟滞非线性系统的随机响应，并运用庞加莱截面、功率谱和最大李雅普诺夫指数进行了数值模拟，揭示了此类系统在随机路面激励下发生混沌运动的可能性。%Chaotic motions of a single DOF vehicle suspension system with nonlinear hysteretic characteristics under random excitation were studied.By using stochastic Melnikov method,the critical condition to cause chaotic motion of the system under bounded noise excitation was derived in the mean square sense.The influences of suspension hysteretic parameters on the system’s chaotic motion were discussed,and the numerical validation was performed by using Poincaré section,power spectrum and the largest Lyapunov exponent (LLE).The results showed that there exist chaotic motions in the suspension system.The random responses of the single DOF vehicle suspension system with nonlinear hysteretic characteristics under the C-class road excitation were simulated and analyzed by using Poincaré section,power spectrum and the largest Lyapunov exponent.The numerical simulation revealed the possibility of the occurrence of chaotic motions in this kind system under stochastic road excitation.