路面激扰与电磁激扰下电动轮车辆系统非线性全局动态特性研究

为研究电动轮车辆系统在路面 电磁联合激励下的非线性振动特性,并挖掘参数与初始条件协同作用下系统全局动力学信息,建立了计及悬架系统和轮胎的非线性弹簧力和阻尼力的电动轮车辆系统两自由度1/4垂向振动非光滑非线性时变动力学模型,考虑外部激励的谐波性和随机性以及电磁激励的分段周期性,得到了含谐波性、随机性和周期性的复杂外激励模型,分析了驱动电机转速与多初值的关联性对系统动力学共存行为及其分岔的影响规律,研究了共存运动的多样性及其吸引域的拓扑构型,揭示了转速对系统全局动力学稳定性的影响机理.结果表明：电机转速与多初值协同作用诱发系统出现多样性的共存运动,共存运动吸引域的拓扑结构复杂多样,部分共存运动的振动幅值可能较大亦可能很小,其全局动力学稳定性差异较大.电机转速与初值的协同作用对电动轮车辆系统非线性振动和全局动态特性的影响不予忽视.本文研究对电动轮车辆系统的动态性能改善和结构优化具有重要的理论意义和工程价值.

Nonlinear Global Dynamic Characteristics of Electric Wheeled Vehicle Systems with Pavement and Magnetic Excitations

In order to study the nonlinear vibration of the electric wheeled vehicle system under the pavement magnetic excitation and to excavate the global dynamic information of the system under the synergistic effect of parameters and initial conditions, a new non smooth nonlinear time varying dynamic model of the two-degree-of-freedom 1/4 vertical vibration of an electric wheeled vehicle system including the nonlinear spring force and damping of the suspension system and tires are established. Complex external excitation models with harmonicity, randomness and periodicity are obtained by considering the harmonicity and randomness of road excitation and the piecewise periodicity of electromagnetic excitation. The influence of the correlation between motor speed and multiple initial values on the coexistence behavior of the system and its bifurcation is analyzed. The diversity of coexisting motions and the topology of their basins of attraction are investigated. The mechanism of the influence of rotational speed on the global dynamic stability of the system is revealed. The results show that the synergistic effect of the motor speed and the multiple initial values induces a variety of coexisting motions in the system. The topological structures of the basins of attraction of coexisting motions are complex and diverse, and the vibration amplitude of some coexisting motions may be large or small, and their global dynamic stability changes greatly. The impact of the synergistic effect of the motor speed and the initial value on the nonlinear vibration and global dynamics of the system cannot be ignored. This research has important theoretical significance and engineering value for the dynamic performance improvement and structural optimization of the electric wheel vehicle system.