Contact Stiffness Model of Joint Surface Considering Continuous Smooth Characteristics and Asperity Interaction

A new model to accurately obtain the contact stiffness of the mechanical joint surface is established, which satisfies the continuous smooth contact characteristics of the asperity and also considers the influence of the asperity interaction. In order to satisfy the continuous and smooth contact characteristics of the asperity, the interpolation interval of the Hermite polynomial function is improved to make the asperity contact stiffness curve smoothly transition in the elastic, elastoplastic and completely plastic stages. Further, the contact situation of the joint surface considering the asperity interaction is explored through micro-contact analysis and mechanism research. Finally, using statistical principles, the microscopic contact model is extended to the entire joint surface, and the contact stiffness model of the joint surface is established. The simulation results show that the asperity stiffness model satisfies the continuous smooth contact characteristics. Surface roughness is the main factor that affects the contact stiffness, and the influence of the asperity interaction cannot be ignored.