面向虚拟样机的机构间隙旋转铰建模与动力学仿真

Dynamic Simulation and Modeling of Revolute Clearance Joint for Virtual Prototyping

含间隙机构的运动/动力学仿真必须考虑间隙及其影响因素对机构动态特性的影响。针对大型重载机构虚拟样机中的间隙旋转铰,建立考虑铰接处两相对运动构件制造和装配误差的旋转铰间隙变化模型。基于间隙矢量模型,描述间隙铰处两构件间的相对运动学关系和基于非线性碰撞接触模式的动力学约束关系。该模型改善了一般虚拟样机仿真软件对间隙铰建模不考虑制造和装配误差的不足,可以提高虚拟样机仿真的可靠性、真实性。对一汽轮机阀门机构进行仿真计算,分析铰间隙、制造和装配误差等因素对机构动力学特性的影响。

The effects of spatial clearance and its influencing factors on the system dynamic responses in kinetic/dynamic simulation of mechanical system with clearance joints should be considered. A revolute clearance vector model in consideration of manufacturing error is developed for the virtual prototyping simulation of large heary-duty mechanism. Based on the clearance vector model, the kinetic relationship between two adjacent linked bodies is obtained. And the dynamic relationship based on the model of nonlinear contact force is also presented. An example is presented to demonstrate the reliability of the proposed model, with different clearance sizes and manufacturing errors.