Impact of Corrugation and Roughness of Surface Upon Normal Contact Stiffness of Flat Joint

Abstract

A contact stiffness of a flat join in engineering surfaces depends upon the presence of corrugation and roughness which are actually on any surface. An efficient method for the analysis of a contact interaction between wavy surfaces is a simulation: statistical methods for the estimate are unacceptable because of a small number of waves and the absence of a proper statistical distribution of their height, and a fractal model manifesting the peculiarities of rough layer structure and the presence of self-affinity is most suitable for the estimate of contact stiffness. 
 In this paper there is carried out an estimate of the impact of corrugation and roughness of an engineering surface upon normal contact stiffness of a flat joint by methods of the computer modeling of the contact interaction between a wavy and fractal (rough) surfaces. With this purpose there was developed a two-level model of the contact interaction of engineering surfaces according to which on the first level there were estimated parameters of wave contact interaction. 
 There were obtained outline spots of a contact on which were modeled fractal surfaces emulating roughness, and estimated the actual spots of a contact. A computer experiment has shown that the dependence of normal contact stiffness upon a load has a vivid non-linear character, and a stiffness of wavy surface is about 30 times larger than a stiffness of a rough layer.