车辆传动轴系动态激励及其响应的仿真研究

应用动态接触有限元法模拟了齿轮啮合的动态过程，得到了齿轮啮合时变刚度曲线；并运用发动机曲轴系的多刚体动力学模型，仿真计算了其动力输出，得到了车辆传动轴系的激励。在建立车辆传动齿轮轴系动态有限元模型时，应用了一种用温度信号控制单元刚度的变化从而实现对齿轮啮合时变刚度变化模拟的新方法，计算了系统的动态响应；并且与以平均刚度代替时变刚度进行计算的结果进行了比较，可知计算传动轴系动响应时，在一定精度范围内，可以用平均啮合刚度作为一种近似的替代。

Study on Dynamic Excitation and Response of Shaft and Gears System in Certain Vehicle

Based on the dynamic contact finite element method,the process of the gears meshing is simulated.As a result,the time-varying mesh stiffness is obtained.Then,the multi-body dynamics model of a certain engine is developed;using this model the dynamic output,which is the external excitation of the vehicle gear and shaft system,is calculated.A new method,by using the temperature variation to control the stiffness of the elements to agree with the time dependant mesh stiffness,is put forward,and the expected result is get.It can be concluded that the change in system natural frequency resulting from the time average of the mesh stiffness is slightly affecting the dynamic response.To some extent,the time average of the mesh stiffness can be used to take place of the time variable one.