Layered structures with rough surfaces and interfaces at contact loading

• DOI: 10.1016/j.ijmecsci.2020.105611
• Publication Date: 2020-03-12T08:01:14Z
• Authors: Qingbing Dong; Yan Li; Jing Wei; Fengxia Lu
• Keywords: 0203 mechanical engineering; 02 engineering and technology; 0210 nano-technology

Abstract Layered structures are used in many applications because of their abilities to protect the surface from wear, corrosion and other damages, but the growth of a thin film inevitably generates a certain amount of roughness on the surface or between the adjacent layers. In this study, a numerical model is developed to address the stress concentrations at the roughened surface/interface under contact loading in plane-strain conditions. A square domain covering the structures of interest is proposed, and the gap between the horizontal edge of the domain and the rough surface is assumed to be filled with a fictitious layer, which may not possibly induce stresses, and the interactions are thus reasonably removed. The coating layer zone between the surface and interface is assumed as an infinitely extended inclusion and the Eshelby's Equivalent Inclusion Method (EIM) is employed to model the layered volumes. The Conjugate Gradient Method (CGM) is adopted to determine the surface pressure in contact areas and eigenstrains in equivalent inclusions. An algorithm mixing the techniques of discrete convolution and fast Fourier transform (DC–FFT) and DCD–FFT is employed to speed up the calculation. The model provides a useful tool to accurately capture the stresses within the roughened areas, and the analysis based on the model potentially gives insight views to enhance the contact behaviors of layered material systems. The model is also capable of solving problems of multi-layered materials as long as the layered volumes are specified.