Finite Element Analysis of Normal Contact Stiffness between Real Rough Surfaces Based on ANSYS

The data of real rough surface are captured by using the morphology measuring instrument LEXT OLS4000. Contraposing the scarcities that no rough surface produced with either statistical model or fractal model can represent the real surface and reflect the surface stress, the real rough surface model is built based on the idea of reverse engineering. ANSYS is employed in research on the normal contact between the real rough surfaces, which is predigested with the contact between a rigid plane and a rough surface. The study shows that hysteresis phenomenon presents itself between the normal loading curve and the normal unloading curve as a result of some asperities´ plastic deformation, which also brings on residual press-stress benefits for material properties on the rough surface after unloading completely and the residual stress varies with the amount of load at the start of unloading. Normal contact stiffness increases first and then decreases along with the normal load, and is also affected by surface topography and the residual surface stress of the micro-body.