A model that predicts the static friction for elastic-plastic contact of rough surfaces is presented. The model incorporates the results of accurate finite element analyses for the elastic-plastic contact, adhesion and sliding inception of a single asperity in a statistical representation of surface roughness. The model shows strong effect of the external force and nominal contact area on the s...

In this paper, we study mixed variational nite element methods for the unilateral problems arising in contact mechanics.The presented discrete spaces can handle the case of non matching meshes in the contact area. We rst state the static problem and then extend it to the frictional contact case, and end with the dynamic frictional problem.

The feet/ground interaction is one of the major problem in the context of dynamic simulation for walking devices. We focus here about the phenomenon of contact. This paper describes a general model for dynamic simulation of contacts between a walking robot and ground. This model considers a force distribution and uses an analytical form for each force depending only on the known state of the ro...

in this work, we study a unilateral contact problem with non local friction of coulombbetween a locking material and a rigid foundation. in the first step , we present the mathematicalmodel for a static process, we establish the variational formulation in the form of a variationalinequality and we prove the existence and uniqueness of the solution. in the second step, usingthe penalty method we...

We present a high-precision determination of the universal contact parameter in a strongly interacting Fermi gas. In a trapped gas at unitarity, we find the contact to be 3.06±0.08 at a temperature of 0.08 of the Fermi temperature in a harmonic trap. The contact governs the high-momentum (short-range) properties of these systems, and this low-temperature measurement provides a new benchmark for...

We investigate and compare a few parallel preconditioning techniques in the iterative solution of large sparse linear systems arising from solid Earth simulation with and without using contact information in the domain partitioning process. Previous studies are focused on using static or matrix pattern based incomplete LU (ILU) preconditioners in a localized preconditioner implementation. Our c...

This communication describes a new approach for controlling static charging (contact electrification), and resulting electrical discharging, that occurs when two contacting materials separate. The prevention of contact electrification is an important problem; unwanted adhesion between oppositely charged materials, spark-initiated explosions, and damage to microelectronic circuitry are some of t...

Abstract The analysis of the sliding electrical contact characteristics between armature and rails is an important research area for electromagnetic railguns. In this paper, a model considering non-ideal factors introduced, magneto-thermal coupling interface are summarized, current temperature distribution outlined. end, measures that can be taken to improve performance presented in terms rail ...