中文摘要：

基于随机平均法研究考虑刚度非线性时DSAX型受电弓弓头悬挂子系统的随机动力学特性．建立弓头悬挂子系统的非线性动力学模型，基于受电弓的结构参数计算获得非线性刚度．弓网间接触压力简化为对弓头悬挂系统的周期和随机组合外激励，建立描述弓头悬挂动态行为的非线性随机微分方程．基于随机平均法得到弓头悬挂子系统的稳态响应统计量，研究非线性强度对稳态响应的影响规律．结果表明，弓头滑板的稳态响应出现随机跳跃，随着非线性强度的变化随机跳跃会产生或消失，即发生分岔．

英文摘要：

This article is concerned with the stochastic dynamics of the suspension subsystem of DSA X pantograph considering nonlinearity of stiffness. Firstly, a nonlinear dynamic model of the suspension subsystem was developed where the nonlinear stiffness was obtained according to physical parameter values of pantograph. The contact force between the pantograph and the overhead contact line excites the subsystem, which had been modeled as a combination of harmonic and random excitation. The nonlinear stochastic differential equation describing the dynamic behavior of the suspension subsystem was formulated. Then, by using the stochastic averaging method, the statistics of the stationary responses of the suspension subsystem was obtained, and the effect of the intensity of nonlinearity on the stationary response was also studied. Numerical results show that the stochastic jump of the stationary response of the carbon strip and its bifurcation as the nonlinearity intensity＇s change occurs.