A physics-based model of a dynamic tangential contact system of lap joints with non-Gaussian rough surfaces based on a new Iwan solution

This paper aims to propose a tangential contact model of a lap joint interface with non-Gaussian surfaces. Relying on the full-stick contact condition, the elastic-plastic deformation of a single asperity and the penetration-dependent friction coefficient are considered in this model. The Johnson system is utilized to generate non-Gaussian asperity height distributions. Furthermore, the physical asperity model and the phenomenological Iwan model are combined to obtain a continuous and convergent Iwan solution by the dimensional analysis method. The initial tangential stiffness, the tangential force required for gross slip, and the slip index of lap joints reveal the hysteresis loop shape, describing the tangential response completely and uniquely, and the first two parameters are proved to own statistical characteristics. Next, the effects of topography parameters on the initial tangential stiffness, the tangential force/displacement required for gross slip, and the slip index are analyzed. Comparisons among the proposed model, the published models, and the published experimental results have also been made. The proposed model is shown to be consistent with the experimental results when the tangential load is insufficient to cause gross slip, while an error is produced when gross slip happens. Additionally, the error could be reduced in the calibrated model.