基于圆锥微凸体的结合面法向接触特性研究

Research on Normal Contact Characteristics of Joint Surface Based on Conical Asperities

为减小等效微凸体体积,使得等效后的微凸体体积更接近实际微凸体体积,将微凸体变形部分等效为圆锥微凸体,并结合分形理论和改进的W-M函数,建立了结合面法向接触刚度和法向接触阻尼模型,并对模型进行仿真分析和实验验证,仿真结果表明,法向接触阻尼随着分形维数的增大而增大,法向接触刚度随着分形维数的增大先增大后减小,并在分形维数为2.6附近取得最大值;法向接触阻尼随着分形粗糙度的增大先增大后减小,法向接触刚度随着分形粗糙度的增大而减小;法向接触阻尼随着塑性指数的增大而减小,法向接触刚度随着塑性指数的增大而增大;将理论分析结果与实验数据进行比较,两者基本保持一致,验证了其正确性。基于圆锥微凸体的结合面法向接触特性模型的提出,为结合面的刚度与阻尼预测和优化机械设备的性能以及结构改进提供良好的依据。

At present,most researches equate the deformation part of the joint surface asperity to the spherical asperity,but the actual volume of the actual asperity is smaller than the volume of the equivalent spherical asperity.Therefore,the deformation part of the asperity is equivalent to the conical asperity,reducing the volume of the asperity when contacting.In combination with the fractal theory and the improved W-M function,the normal contact stiffness and normal contact damping models of the joint surface are established,and the model is simulated and verified by experiments,The simulation results show that the normal contact damping increases with the increase of fractal dimension,and the normal contact stiffness first increases and then decreases with the increase of fractal dimension,and reaches the maximum value near the fractal dimension of 2.6;The normal contact damping first increases and then decreases with the increase of fractal roughness,and the normal contact stiffness decreases with the increase of fractal roughness;The normal contact damping decreases with the increase of plasticity index,and the normal contact stiffness increases with the increase of plasticity index;The theoretical analysis results of this model are compared with the experimental data,and they are basically consistent,which verifies the correctness of this model.The normal contact characteristic model of the joint surface based on the conical asperity provides a good basis for predicting the stiffness and damping of the joint surface,optimizing the performance and improving the structure of mechanical equipment.