Modeling of normal contact stiffness for surface with machining textures and analysis of its influencing factors

A new contact stiffness model for the rough surface with different machining textures is established. The studied surface consists of regular surface machining texture in the global scale and stochastic micro-asperities in the local scale. The proposed model improves upon previous work that considers only the effect of stochastic as-perities and completely ignores that of the machining textures generated by different machining methods. The analytical expression to calculate the contact stiffness of the studied textured surface is derived and numerical results are obtained via the finite element method. A high-precision test bench to measure the interface contact stiffness of the workpiece with different surface textures is designed. The measured results and simulated results are directly compared to demonstrate the validity of the proposed method. The effects of different texture types and surface roughness values on the contact stiffness of the proposed textured surface are analyzed. The proposed method provides a research basis for the accurate calculation of nonlinear contact stiffness and dynamic char-acteristics of the surface with complex texture topography.