Modeling and experimental identification of contact pressure and friction for the analysis of non-conforming elastic contact

In this paper, we propose an experiment-based method for the modeling and the identification of the contact pressure and friction distribution on the interface of a non-conforming contact. In this method a two-dimensional contact model is established. The distributed contact pressure and friction are approximated by Taylor series and their relationship with the local displacements near the contact interface are modeled by using a half-space based approach. The parameters of the proposed contact model include the contact center, the half length of the interface, and the orders and coefficients of the Taylor series. They are identified by minimizing the residual between the computed displacement field and the measured one through an alternating optimization. The contact pressure and friction are reconstructed by the optimal parameters. A full-field optical method, namely segmentation-aided digital image correlation, is used not only to experimentally measure the local displacements but also to initialize the model parameters. The proposed mechanical modeling requires fewer assumptions compared with the classic models. The parameter identification only uses the local displacements and does not require boundary conditions of the contact members. The results of the simulated and real-world experiments show that the proposed method is able to reliably recover the contact stress and it is robust against the displacement measurement uncertainty. (C) 2017 Elsevier Ltd. All rights reserved.