Study on Elasto-Plastic Deformation Characteristics of Micro-Bumps on Electrical Contact Surface

Based on the study of fractal rough surface topography, a finite element analysis model of elastic–plastic contact deformation of micro-convex body considering the combination of various material properties is established. The elastic–plastic deformation process of a single micro-convex body on rough surface is calculated and analyzed by using the model. The corresponding relationship among contact area, contact pressure and compressive displacement of micro-convex body is obtained. The distinguishing principles of three typical deformation stages of micro-convex body are pointed out, i.e. complete elastic deformation, elastic–plastic deformation and complete plastic deformation. According to the finite element calculation results, an empirical formula for elastoplastic contact deformation of micro-convex bodies considering the effect of material properties is derived. Compared with other models, the advantages of the empirical formula in accuracy and generality are proved, which is applicable to most engineering materials and lays a foundation for establishing a more complete mathematical model for electrical contact.