Statistical analysis of tangential contact stiffness of joint surfaces

Abstract

To investigate the tangential contact stiffness of joint surfaces, the asperity contact of the joint surfaces is considered as an elliptically shaped contact, with the major and minor semi-axes of the contact areas assumed to follow a two-dimensional Gamma distribution. Hertz theory for the pressure distribution on an elliptical contact area is applied to solve for the tangential contact stiffness in a single asperity. Numerical results reveal a change in the tangential contact stiffness, with the influential factors being normal load, tangential load, eccentricity of elliptical asperities, correlation coefficient of asperity distribution, measured asperity height, and standard deviation of asperity distribution on joint surfaces. All of the results should provide theoretical guidance for evaluating or refining the tangential contact stiffness of joint surfaces.

A new elliptical microcontact model considering elastoplastic deformation

“…In order to make the contact pressure change continuously, smoothly and monotonously during the elastic-plastic contact deformation stage of the asperity, a low order composite curve is used in this paper to model the average contact pressure change of the asperity in the elasticplastic contact phase. According to the continuous and smooth condition of pressure changes at the critical yield point, the following equations can be obtained by equations (15), (16) and (22)…”

“…Nevertheless, when the contact analysis and surface micro-topography deformation analysis are carried out for a specific surface, it is obviously impossible to make elliptical contact simplified. [16][17][18] Bush et al 19 assumed that the shape of asperities is ellipsoidal and analyzed the contact deformation with Hertz contact model. Therefore, the model is limited to the Hertz contact theory and only considers the elastic deformation.…”

Modeling of the Loading–Unloading Contact of Two Cylindrical Rough Surfaces with Friction

“…Statistical methods are commonly used to analyze the contact problems of rough surfaces. There are many statistical models proposed recently, such as GW (Greenwood and Williamson) model [1][2][3], CEB (Chang, Etsion and Bogy) model [4], KE (Kogut and Etsion) model [5][6][7], the ellipse model [8,9], the size-dependent plasticity model [10] and so on. In particular, Kogut and Etsion [11,12] proposed a model that predicts the static friction for elastic-plastic contact of rough surfaces (KE friction model); Brizmer et al [13] developed a numerical model for the elastic-plastic spherical contact under combined normal and tangential loading in full stick based on their single asperity models in full stick condition [14,15]; Cohen et al [16,17] proposed statistical models for flat contacting rough surfaces and for spherical contacting rough surfaces under combined normal and tangential loading with the plasticity index ψ≤ 8 respectively; Li et al [18] extended the spherical model of Cohen up to ψ= 32; Wang et al [19] developed a model to predict the static friction coefficient considering the multi-scale nature of roughness; Zheng et al [20] proposed an improved static friction model for elastic-plastic contacting surfaces based on KE friction model.…”

Loading-unloading contact model between three-dimensional fractal rough surfaces

“…Subsequently, many scholars extended the GW model to deal with other rough surface contact problems about engineering application, such as oscillatory sliding contact, 6 adhesive contact, 7,8 asperity interaction 9 and contact stiffness of joint surfaces. 10 Kadin 11 established a rough surface loading-unloading contact statistical model based on a loadingunloading finite element model of single asperity provided by Etsion. 12 In this model, asperities a Electronic mail: yuanyuanhhhhhh@163.com may undergo plastic deformation during loading and unloading, resulting in residual strain and the change of asperity height distribution function.…”