N. Menga

Fast High-Resolution Simulation of the Gross Slip Wear of Axially Symmetric Contacts

ABSTRACT In the present article, we study the development of a wear profile in an axially symmetric contact under conditions of gross slip and assumption of the Reye-Archard wear criterion. Simulations are carried out using the method of dimensionality reduction and a full finite element method (FEM) formulation. The calculation time of the proposed model is several orders lower than that of FEM-based models and allows for much higher spatial resolution.

The sliding contact of a rigid wavy surface with a viscoelastic half-space

In this paper, the contact of a rigid sinusoid sliding on a viscoelastic half-space is studied. The solution of the problem is obtained by following the path drawn by Hunter for cylindrical contacts. Results show that depending on the remote applied load, a transition from full contact conditions to partial contact may occur depending on the sliding velocity. This effect, which is not observed in smooth single asperity contacts, is related to the viscoelastic stiffening of the material and to the periodicity of the contacts. Frictional properties as well as contact area, displacement and pressure distributions are discussed in detail.

A Winkler solution for the axisymmetric Hertzian contact problem with wear and finite element method comparison

Contact problems with wear are often modelled according to the Reye–Archard law that applies locally to the wearing parts. In the transient regime, for geometries where the contact area cannot be assumed to be constant, a simple solution is possible when using the Winkler simplifying assumption. Here, we obtain such a solution in the axisymmetric contact problem, for an initially Hertzian geometry. Also, we explore the possibility to improve the solution by assuming that the Winkler constant adapts to the changing size of the contact. The correction is relevant in intermediate regimes before the solution tends to a ‘rigid’ asymptotic regime, independent of the elastic modulus. Comparison with a full finite element method simulation shows that the error in either contact area or peak pressure tends to be reduced from the initial error intrinsic in the Winkler assumption; however, the improvement remains small.

The multiple V-shaped double peeling of elastic thin films from elastic soft substrates

Abstract In this paper, a periodic configuration of V-shaped double peeling process is investigated. Specifically, an elastic thin film is detached from a soft elastic material by applying multiple concentrated loads periodically distributed with spatial periodicity λ. The original Kendall’s idea is extended to take into account the change in elastic energy occurring in the substrate when the detachment fronts propagate. The symmetric configuration typical of a V-peeling process causes the energy release rate to be sensitive to variations of the elastic energy stored in the soft substrate. This results in an enhancement of the adhesion strength because part of the external work required to trigger the peeling mechanism is converted in substrate elastic energy. A key role is played by both spatial periodicity λ and elasticity ratio E/Eh, between tape and substrate elastic moduli, in determining the conditions of stable adhesion. Indeed, the presence of multiple peeling fronts determines a modification of the mechanism of interaction, because deformations close to each peeling front are also affected by the stresses related to the other fronts. Results show that the energy release rate depends on the detached length of the tape so that conditions can be established which lead to an increase of the supported load compared to the classical peeling on rigid substrates. Finally, we also find that for any given value of the load per unit length, an optimum value of the wavelength λ exists that maximizes the tolerance of the system, before unstable propagation of the peeling front can occur.

Viscoelastic Contact of a Half-Plane Sliding Over a Slightly Wavy Rigid Surface

In this paper, the sliding contact of a rigid sinusoid over a viscoelastic halfplane is studied by means of an analytical procedure that reduced the original viscoelastic system to an elastic equivalent one, which has been already solved in [1]. In such a way, the solution of the original viscoelastic contact problem requires just to numerically solve a set of two integral equations. Results show the viscoelasticity influence on the solution by means of a detailed analysis of contact area, pressure and displacement distribution. A particular attention is paid to the transition from full contact to partial contact conditions.Copyright