Friction analysis at elastic-plastic contact of rough surfaces using n-point asperity model

Abstract

The paper describes a theoretical study of friction at elastic-plastic contact of rough surfaces in n-point asperity model framework and based on accurate finite element analysis of elastic-plastic deformation of single asperity contact. Plasticity index, a well-defined nondimensional parameter is used to study the prospective situations arising out of variation in material properties and surface roughness. Using practical values of material properties and surface roughness parameters, results are obtained for the behavior of applied load, friction force, and coefficient of friction as a function plasticity index and mean separation of surfaces. It is observed that with increase in amount of plastic deformation, the load required to be applied for maintaining a particular level of separation between contacting surfaces increases while the frictional force decreases. Coefficient of friction is independent of applied load in predominantly plastic domain of deformation but varies nonlinearly in other domains of deformation. Also, for the same applied load the coefficient of friction increases with increase in elastic deformation.

Tribological properties of multilayer tetrahedral amorphous carbon coatings deposited by filtered cathodic vacuum arc deposition

“…However, in this study, because the plasticity index was 6-10, the contact state belonged to the elastic-plastic contact, and the Hertzian contact pressure and CoF were not correlated. However, Waghmare et al [26,27] reported that the elasticity index of H/E should be considered along with the Hertz contact pressure. Therefore, as shown in Figs.…”

Correlation between surface roughness parameters and contact stress of gear

“…With the help of a single-peak contact model of a single asperity and 3D rough surface contact model based on asperities parameters in Wen et al, 43,44 surface stress and shear stress of the workpiece surface can be obtained under a given load. Similar to the work of others, [21][22][23][24][25][26][27][28] for the convenience and efficiency of the calculation of contact model, the interaction between asperities is not taken into account.…”

“…To solve this problem, Wen and Tang, 17 Wei et al, 18 Wen et al, 19 and Wang et al 20 used the elastic-plastic mechanics theory to propose that in the meshing and contact analysis of rough tooth surface, the plastic hardening of asperities resulted in complicated influences of surface roughness on tooth surface contact. At the same time, some researchers put forward a series of contact models [21][22][23][24][25][26][27][28] to analyze the influence of asperities on rough surfaces. The above analysis shows that the influence of tooth surface roughness on gear contact or fatigue performance cannot be ignored.…”

Adhesive Friction Based on Accurate Elastic-Plastic Finite Element Analysis and n-Point Asperity Concept

“…Same expressions are incorporated in present section to model elastic-plastic adhesive contact using n-point asperities. In earlier study also the present authors (Waghmare and Sahoo, [22]) have successfully incorporated the KE expressions for non-adhesive frictional contact. The present adhesive friction contact study is based upon RG's slip and yield theory of contacting asperities.…”

“…The slipping of the asperities because of tangential load may occur either in purely elastic or elasticplastic stage-I zone of deformation. Therefore, resistance offered by such asperities before slip is calculated as frictional force using equation (19) while the resistance offered by asperities which do not slip is calculated by equation (22). …”