Modelling mechanical interfaces experiencing micro-slip/slap

Surface-to-surface contact interfaces significantly affect structural behaviour. Therefore, accurate modelling of the stiffness and damping characteristics of such interfaces is crucial for dynamic response analysis of assembled structures. Due to the development of nonlinear interactions, such as slip and slap mechanisms, modelling and analysis of the contact interfaces is a challenging task. The nonlinear effects of the slip and slap mechanisms need to be considered in interface models particularly when the amplitude of the structural response is high. This article considers finite element (FE) modelling of a compound structure containing a surface-to-surface contact interface, i.e. a bolted lap-joint. The joint, modelled using thin-layer element theory, experiences micro-slips/slaps under extreme loading conditions of the structure and to take into account these behaviours, the thin-layer element is assumed to behave in a nonlinear manner. In order to identify the nonlinear uncertainties in the joint interface, the real structure is subjected to vibrational testing, and its dynamical behaviour at different loading levels is extracted. The parameters of interfacial elements are tuned in such a way that the resultant FE model predicts the experimental results with a high accuracy.