The purpose of the paper is to give a pedagogical introduction to the multiple time-scale technique, on the example of the high friction limit of the Kramers equation. We begin with a discussion of the standard perturbation technique as presented in van Kampen’s reference book V K , which will be shown to fail in the long-time limit. Application of the multiple time-scale technique avoids these...

We consider the dynamics of bubble growth in the Minimal Standard Model at the electroweak phase transition and determine the shape and the velocity of the phase boundary, or bubble wall. We show that in the semi-classical approximation the friction on the wall arises from the deviation of massive particle populations from thermal equilibrium. We treat these with Boltzmann equations in a fluid ...

In an admittance-controlled haptic device, input forces are used to calculate the movement of the device. Although developers try to minimize delays, there will always be delays between the applied force and the corresponding movement in such systems, which might affect what the user of the device perceives. In this experiment we tested whether these delays in a haptic human-robot interaction i...

Recently friction stir welding for manufacturing of welded tubes has been developed. Friction stir welding is a continuous solid state welding process in which a non-consumable rotating tool using severe plastic deformation Can join materials can be join materials. Commonly, a portion of a specially shaped rotating tool is plunged between metalsjoint cross section and adjacent faces of the join...

Dynamic modelling is an important issue in legged locomotion. However, friction has been neglected in most studied models. The aim of this work is the experimental determination of frictional effects over leg dynamics. For this purpose, previous work on friction modelling in robot manipulators (1), (3), has been followed and similar results have been achieved. However, a new friction component ...

This work revealed the results of comparative surveys of the impact of formed surface layer TiN and CrN and two component surfaces layer TiN-steel and CrN-steel. The slide couple worked in conditions of lubricating the friction area with Lotos Syntetyk 5W/40 and Castrol GTX Magnatec 5W/40 engine oils. In the friction couple the counter sample was made from CuPb30 bearing alloy. The tribological...

Recently friction stir welding for manufacturing of welded tubes has been developed. Friction stir welding is a continuous solid state welding process in which a non-consumable rotating tool using severe plastic deformation Can join materials can be join materials. Commonly, a portion of a specially shaped rotating tool is plunged between metalsjoint cross section and adjacent faces of the join...

The present work aims at reducing the friction of rubber soles sliding on ceramic floorings. Fitting bored cylindrical protrusions with different diameters on rubber soles was proposed. Experiments were carried out to evaluate the performance of the proposed protrusions in increasing friction coefficient at dry and contaminated floorings. It was found that, at dry sliding, friction coefficient ...

The friction is detrimental to the normal work of the servo system, but the friction mechanism is very complicated. In this paper, Tustin friction model is used as the friction parameter identification, reflecting the phenomenon of friction in the system, and laying the foundation for the friction compensation. Tustin model is a nonlinear friction one, and the friction properties can be reflect...

in all engineering applications where solid surfaces slide on each other, friction plays an important role. it becomes even more important, particularly in metal forming processes where the two sliding materials are metallic. among forming processes, forging is an important process, because of improving material structure, mechanical properties and reducing production time. an inverse analysis ...