人车路耦合系统的非线性振动特性及试验研究

Nonlinear vibration characteristics and experimental validation of a human-vehicle-road coupled system

为了解决车辆行驶中产生的复杂非线性振动响应问题,建立三自由度人车路耦合非线性动力学模型。基于扭转几何变形非线性特征,利用拉格朗日方程推导出三自由度人车路耦合非线性振动方程,该方程中的正弦和余弦函数项来源于几何非线性扭转变形。针对自由振动,给出非线性恢复力曲面、势能曲面及固有频率解析表达式。针对强迫振动,运用数值仿真方法分析车辆质量、转动惯量、乘客质量、座椅刚度/阻尼、悬架刚度/阻尼、阻尼、质心位置、路面波长及波幅等系统参数对振幅速度响应曲线的影响。搭建人车路耦合振动系统的实验平台,通过振动实验结果验证理论分析与数值结果的可靠性。研究结果表明:该三自由度非线性动力学耦合系统可精确描述人车路耦合系统的响应特性,合理选择系统参数能够有效减小振动响应幅值和提升乘坐舒适性。

In order to solve the problem of complex nonlinear vibration response in the traveling vehicle system,a nonlinear dynam-ical model for a coupled human-vehicle-road system with three-degree-of-freedom is established.The coupled vibration equations of human-vehicle-road with three-degree-of-freedom are derived by the Lagrange equation,and the sine and cosine functions of this system arise from the geometric nonlinearity of torsional deformation.The nonlinear restoring force surfaces,potential energy sur-faces and analytical expressions of natural frequency are obtained for the free vibration of the human-vehicle-road system.For the forced vibration,the influence of vehicle system parameters of vehicle mass,moment of inertia,passenger mass,seat stiffness,suspension stiffness,damping,centroid position,road wavelength and wave amplitude on the response curves of amplitude veloci-ty is analyzed by using the numerical simulation method.The experimental platform of the coupled human-vehicle-road vibration system is built and the reliability of theoretical analysis and numerical results is verified by the experiments.The results show that this nonlinear dynamical coupled system with three degree-of-freedom can accurately describe the human-vehicle-road response characteristics,and reasonable selection of the system parameters can effectively reduce the vibration response amplitude and im-prove the human riding comfort.