On models of contact surfaces including anisotropy for friction and adhesion and their experimental validations (original) (raw)

On coupled models of anisotropic contact surfaces and their experimental validation

Wear, 2008

The necessity to apply a coupled contact interface model including anisotropy for both adhesion and friction is shown via a set of experiments for a rubber surface possessing a periodical waviness, and therefore, an obvious anisotropic structure. The focus of experimental investigations is placed upon the measurements of the global macro characteristics such as global forces and trajectories of a sliding block in order to validate the proposed computational model.

Covariant description of contact interfaces considering anisotropy for adhesion and friction

Computer Methods in Applied Mechanics and Engineering, 2006

A covariant description for contact problems including anisotropy for both adhesion and sliding domains is proposed. The principle of maximum dissipation is used to obtain a computational model in the case of quasi-static motion. Various cases including curvilinear anisotropy on arbitrary surfaces illustrating the possibility to model machined surfaces are considered. The part is served to be a necessary preparation for further finite element implementations and numerical analysis.

On the modelling of complex anisotropic frictional contact laws

International Journal of Engineering Science, 2004

In this paper, the formulation of complex anisotropic frictional models with orthotropic friction condition and non-associated sliding rule is discussed. The friction law is described by a superellipse, which allow to consider a wide range of convex friction condition by simply varying the roundness factor affecting the shape of the limit surface. The sliding potential is also a superellipse but with a different semi-axis ratio, which lead to a non-associated sliding rule. For bodies in contact, the Signorini conditions can be formulated in terms of velocities and combined with the sliding rule to give the frictional contact law describing interfacial interactions. Its is shown that the frictional contact law as well as its inverse can be derived from the same scalar valued function called bi-potential. Due to the non-associated nature of the law, this relation is implicit. The advantage of the present formulation lies in the existence of stationary points of a functional, called bi-functional, that depends on both the displacements and the stresses.

Micromechanical analysis of friction anisotropy in rough elastic contacts

International Journal of Solids and Structures, 2014

Computational contact homogenization approach is applied to study friction anisotropy resulting from asperity interaction in elastic contacts. Contact of rough surfaces with anisotropic roughness is considered with asperity contact at the micro scale being governed by the isotropic Coulomb friction model. Application of a micro-to-macro scale transition scheme yields a macroscopic friction model with orientation-and pressure-dependent macroscopic friction coefficient. The macroscopic slip rule is found to exhibit a weak non-associativity in the tangential plane, although the slip rule at the microscale is associated in the tangential plane. Counterintuitive effects are observed for compressible materials, in particular, for auxetic materials.

Friction and adhesion

2006

The studies carried out on adhesion by the group "Modeling in Contact Mechanics" at the LMA are reviewed in this paper and recent applications are presented. Based on the introduction of the adhesion intensity variable developed by M. Frémond, different forms of a model coupling adhesion to unilateral contact and friction have been developed. The formulations are given either under the form of implicit variational inequalities or the one of complementarity problems. Both quasi-static and dynamic formulations are considered. The model is non smooth because we do not use any regularization for the unilateral conditions and for the friction, i.e. Signorini conditions and strict Coulomb law are written. In the thermodynamics analysis, the state and the complementarity laws are then written using subdifferentials and differential inclusions because of the non convexity and non differentiability of the potentials. For the dynamics, the formulation is given in term of differential measures in order to deal with the non continuity of the velocities that may occur in the solutions. This work therefore owes much to the theories and the numerical scheme developed by J.-J. Moreau and M. Jean.

Modeling the surface topography dependence of friction, adhesion, and contact compliance

MRS Bulletin

The small-scale topography of surfaces critically affects the contact area of solids and thus the forces acting between them. Although this has long been known, only recent advances made it possible to reliably model interfacial forces and related quantities for surfaces with multiscale roughness. This article sketches both recent and traditional approaches to their mechanics, while addressing the relevance of nonlinearity and nonlocality arising in soft- and hard-matter contacts.Graphical abstract

Influence of frictional anisotropy on contacting surfaces during loading/unloading cycles

International Journal of Non-Linear Mechanics, 2006

This paper presents numerical investigations on the loading and unloading of a three-dimensional body in frictional contact with a rigid foundation. The evolution of the sliding process during loading/unloading cycles is analyzed. The important case of anisotropy is examined along with the effect of the sliding rule. The solution algorithm is based on a variational inequality which combine the contact problem and the frictional problem. The numerical results of the punch problem show the hysteretic and irreversible behavior occurring when friction is anisotropic. ᭧

Interface models coupling adhesion and friction

Comptes Rendus Mecanique, 2011

Interface models coupling friction and adhesion, where adhesion is regarded as interface damage, are briefly reviewed. The most widely used cohesive zone models are presented and discussed. A general framework for these laws, recently developed by Del Piero and Raous in the form of a unified model, is outlined. As an example, it is here established that the RCCM (Raous-Cangémi-Cocou-Monerie) model is a specific case in this general framework. The variational formulation and some associated solvers are briefly recalled in the context of non smooth mechanics in the cases of both quasi-static and dynamic problems. A few examples in various fields of application are given. Lastly, some open problems and ongoing researches in this field are presented and discussed.

Constitutive model for 2D analysis of iso-kinematic frictional contact problems

abcm.org.br

During contact between two surfaces, a part the normal pressure between the surfaces, tangential forces that involve dissipative phenomena related to friction, occur. Modeling the interface friction involves adherence and slipping. This last effect may include evolution equations considering displacement hardening with isotropic or kinematic surfaces involved. Isotropic conditions are generally considered, what may be inadequate to cyclic loadings. Kinematic models address this difficulty and should handle these cases better. Here a kinematic model is formulated, developed and implemented for two-dimensional problems. Corotational measures are used in the setting of the constitutive incremental equations for quasi-static conditions, without thermal coupling. An implicit numerical scheme is used to develop the solution procedure. A few cyclic cases are used to verify the model, followed by an application problem. Results are compared to available solutions with acceptable agreement.