نتایج جستجو برای: friction contact

تعداد نتایج: 192458  

Gear’s normal contact stiffness played an important role in the mechanical equipment. In this paper, the M-B fractal model is modified and the contact surface coefficient is put forward to set up the fractal model, considering the influence of friction, which could be used to calculate accurately the involute arc cylindrical gears’ normal contact stiffness based on the fractal theory and Hertz ...

Journal: :Ultramicroscopy 2004
Robert W Stark Georg Schitter Andreas Stemmer

Friction forces in the tip-sample contact govern the dynamics of contact mode atomic force microscopy. In ambient conditions typical contact radii between tip and sample are in the order of a few nanometers. In order to account for the large interaction area the dynamics of contact mode atomic force microscope (AFM) is investigated under the assumption of a multi-asperity contact interface betw...

2004
Laurent Baillet Taoufik Sassi

This paper presents a mixed variational framework and numerical examples to treat a bidimensional friction contact problem in large deformation. Two different contact algorithms with friction are developed using the 2D finite element code PLAST2. The first contact algorithm is the classical node-on-segment, and the second one corresponds to an extension of the mortar element method to a unilate...

2013
Philipp Damm Joern Dymke Robert Ackermann Alwina Bender Friedmar Graichen Andreas Halder Alexander Beier Georg Bergmann

Friction-induced moments and subsequent cup loosening can be the reason for total hip joint replacement failure. The aim of this study was to measure the in vivo contact forces and friction moments during walking. Instrumented hip implants with Al2O3 ceramic head and an XPE inlay were used. In vivo measurements were taken 3 months post operatively in 8 subjects. The coefficient of friction was ...

2015
Philipp Damm Alwina Bender Georg Bergmann

Loosening of the artificial cup and inlay is the most common reasons for total hip replacement failures. Polyethylene wear and aseptic loosening are frequent reasons. Furthermore, over the past few decades, the population of patients receiving total hip replacements has become younger and more active. Hence, a higher level of activity may include an increased risk of implant loosening as a resu...

2003
Lior Kogut Izhak Etsion

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...

2012
Liliang Wang Liliang WANG

During high-temperature ball-on-disc tests of aluminium against steel, hot aluminium deformsand wear track evolves. The individual contributions of ploughing and shearing to theapparent friction and the contact pressure are unknown. The aim of this chapter was todevelop a model capable of determining these parameters. It was found that during high-temperature ball-on-disc tests,...

Journal: :JNW 2014
Yuhuan Cui Jingguo Qu Hongbo Shao Aimin Yang Yamian Peng

It is a highly nonlinear problem of 3-D elastoplastic contact with friction. To obtain the key information about the real size, displacement and traction in contact zone, the elements in contact and plastic zone should be subdivided. However, the increase of degrees of freedom is limited by the problem-solving scale when traditional BEM is used, for a larger memory size is required and the solu...

2002
I. Nogueira R. Gras

Mechanical engineering often uses fluid lubrication to limit friction. Even in the presence of a lubricant, metallic contact between the sliding surfaces may readily occur. In running-in, the oil film thickness can be so thin that contact arises at the summit of asperities, thus, increasing both the friction coefficient and wear. Such regimes are the so-called mixed or boundary lubrication. In ...

Journal: :Physical review. E, Statistical, nonlinear, and soft matter physics 2015
Fernando Alonso-Marroquin Pengyu Huang Dorian A H Hanaor E A Flores-Johnson Gwénaëlle Proust Yixiang Gan Luming Shen

Using spheropolygon-based simulations and contact slope analysis, we investigate the effects of surface topography and atomic scale friction on the macroscopically observed friction between rigid blocks with fractal surface structures. From our mathematical derivation, the angle of macroscopic friction is the result of the sum of the angle of atomic friction and the slope angle between the cont...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید