Numerical study of scratch velocity effect on recovery of viscoelastic–viscoplastic solids

The scratch test is a classical way to investigate the abrasive resistance of coatings and substrates. Because of the complex phenomena involved, the use of refined finite element analysis is often required to analyze the influence of specific parameters. In this paper, the influence of the tip velocity on the scratch recovery of polymer-like time-dependent solids is qualitatively investigated. More precisely the response of three constitutive models is analyzed: an elastic–viscoplastic model, a linear viscoelastic model and finally a viscoelastic–viscoplastic model. This last model is an original assembly based on the connection in series of the elastic–viscoplastic model and the linear viscoelastic model. For that, a new method allowing the connection in series of two different rheological models in a FE code is presented. To analyze the numerical results, the concept of representative stress and representative strain rate of a scratch test is introduced.