Elastic-Plastic Contact Analysis of Single Layer Solid Rough Surface Model using FEM

Abstract

Evaluation of contact pressure, surface and subsurface contact stresses are essential to know t he functional response of surface coatings and the contact behavi or mainly depends on surface roughness, material property, thickness of layer and the manner of loading. Contact parameter evaluation of real rough surface contacts mostly relies on statistical singl e asperity contact approaches. In this work, a three dimensional layer ed solid rough surface in contact with a rigid flat is modeled and analyzed using finite element method. The rough surface of layered solid is generated by FFT approach. The generated rough surface is exported to a finite element method based ANSYS package through which the bottom up solid modeling is employed to create a de formable solid model with a layered solid rough surface on top. Th e discretization and contact analysis are carried by using the same ANSYS package. The elastic, elastoplastic and plastic deformations are continuous in the present finite element method unlike many other contact models. The Young's modulus to yield strength ratio of laye r is varied in the present work to observe the contact parameters effe ct while keeping the surface roughness and substrate material proper ties as constant. The contacting asperities attain elastic, elastopla stic and plastic states with their continuity and asperity interaction phen omena is inherently included. The resultant contact parameters show tha t neighboring asperity interaction and the Young's modulus to yie ld strength ratio of layer influence the bulk deformation consequentl y affect the interface strength.