This paper presents a new integral approximation of frictional contact problems under finite deformations and large sliding. Similar to other augmented Lagrangian based formulations, the proposed method expresses impenetrability, friction and the relevant complementarity conditions as a non-smooth equation, consistently linearized and incorporated in a generalized Newton solution process. Howev...

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...

After clutch engagement in the post-lockup phase, the contact stiffness between friction materials and separators plays an important role in the dynamic behaviour of an Automatic Transmission (AT). The friction material deteriorates progressively during the service-life of a clutch, thus affecting the contact stiffness. The deterioration therefore changes the dynamic behaviour of the AT. In ord...

Numerous works in Computational Mechanics are dedicated to the simulation of multi-body systems with contact and friction. The case of dense multi-contact assemblies is one of the more complex one: the problem have often a large number of unknowns and the non uniqueness of solutions is usual. Moreover this problem becomes harder when the Coulomb’s friction or more complex laws are introduced. I...

When two macroscopic bodies in contact slide, energy is dissipated. However, at the nanoscale, tiny amounts of energy can also be dissipated when the sliding bodies are not in contact with each other. Such non-contact form of friction — the origin of which has been associated with van der Waals (vdW) forces — has been measured with highly sensitive atomic force microscopy (AFM). In a friction f...

An approach is developed to analyze the multiharmonic forced response of large-scale finite element models of bladed disks taking account of the nonlinear forces acting at the contact interfaces of blade roots. Area contact interaction is modeled by area friction contact elements which allow for friction stresses under variable normal load, unilateral contacts, clearances, and interferences. Ex...

A general interface element is developed for dynamic response analysis of structures with jointed interfaces, which can account for damping due to both impact and friction. Contact effects are included through a segment-to-segment contact model which considers the stick-slip-slap behavior at every point along the joint interface. A nonlinear friction law is adopted at the interface to describe ...

This paper presents frictional characteristics of thrust bearing in scroll compressor. The coefficient of friction in thrust bearing was measured by both elemental friction test and loss classification based on the performance test of actual scroll compressor, and investigated frictional characteristics focusing on the behavior of sliding portion which affects the generation of oil film by expe...

We have measured the surface topography and calculated the surface roughness power spectrum for an asphalt road surface. For the same surface we have measured the friction for a tire tread compound for velocities 10(-6) m s(-1) < v < 10(-3) m s(-1) at three different temperatures (at -8 °C, 20 °C and 48 °C). The friction data was shifted using the bulk viscoelasticity shift factor a(T) to form ...

This paper aims to investigate the microscopic friction mechanism based on in situ microscopic observation in order to record the deformation and contact situation of friction lining during the frictional process. The results show that friction coefficient increased with the shear deformation and energy loss of the surfacee, respectively. Furthermore, the friction mechanism mainly included adhe...