An Experimental Study on the Effect of Surface Texture on Contact Stiffness Using Soft Material

Abstract

Contact interface is one of the most important factors in a mechanical contact because it is the place where friction, sound, and heat originate. It is therefore inevitable that modeling various phenomenon related to contact dynamics requires a proper representation of the contact interfaces. One of the methods in representing the behavior of two surfaces in contact is by using the parameter of contact stiffness. In this study, the effect of surface texture on contact stiffness is analyzed. the texture was used in order to reduce the randomness of surface roughness. the soft material was chosen to achieve a pure elastic contact thus preventing plastic deformation to the asperities. the analysis was conducted by using an indentation method employing a steel ball with a relatively small indentation force. the result show contact stiffness values of the textured surfaces were smaller than that of smooth surface. This is particularly observed at low normal load at which total deformation of the surface is relatively small compared to the asperities height. This decrease in the contact stiffness value of the textured surfaces can be related to the reduction in the real contact area.