scholarly journals Rate-, state-, and pressure-dependent friction model based on the elastoplastic theory

Friction ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 768-783 ◽  
Author(s):  
Shingo Ozaki ◽  
Takeru Matsuura ◽  
Satoru Maegawa
Keyword(s):  
Friction Force ◽  
Contact Area ◽  
Contact Surface ◽  
Internal State ◽  
Friction Model ◽  
Real Contact Area ◽  
State Variables ◽  
Real Contact ◽  
Model Based ◽  
Acrylic Plate

AbstractAdhesion is one of essences with respect to rubber friction because the magnitude of the friction force is closely related to the magnitude of adhesion on a real contact area. However, the real contact area during sliding depends on the state and history of the contact surface. Therefore, the friction force occasionally exhibits rate-, state-, and pressure dependency. In this study, to rationally describe friction and simulate boundary value problems, a rate-, state-, and pressure-dependent friction model based on the elastoplastic theory was formulated. First, the evolution law for the friction coefficient was prescribed. Next, a nonlinear sliding surface (frictional criterion) was adopted, and several other evolution laws for internal state variables were prescribed. Subsequently, the typical response characteristics of the proposed friction model were demonstrated, and its validity was verified by comparing the obtained results with those of experiments conducted considering the contact surface between a rough rubber hemisphere and smooth acrylic plate.

Scale effects on the attachment pads and friction forces in syrphid flies (Diptera, Syrphidae)

2001 ◽  
Vol 204 (8) ◽  
pp. 1421-1431 ◽  
Author(s):  
S. Gorb ◽  
E. Gorb ◽  
V. Kastner
Keyword(s):  
Body Mass ◽  
Friction Force ◽  
Contact Area ◽  
Scale Effects ◽  
Real Contact Area ◽  
Resistance Force ◽  
Friction Forces ◽  
The Real ◽  
Frictional Properties ◽  
Real Contact

To test the role of constructional and dimensional factors in the generation of friction force by systems of setose attachment pads, six species of syrphid fly (Platycheirus angustatus, Sphaerophoria scripta, Episyrphus balteatus, Eristalis tenax, Myathropa florea and Volucella pellucens) were studied using light and scanning electron microscopy. Flies were selected according to their various body mass and attachment pad dimensions. Such variables as pad area, setal density, the area of a single setal tip and body mass were individually measured. A centrifugal force tester, equipped with a fibre-optic sensor, was used to measure the friction forces of the pads on a smooth horizontal surface made of polyvinylchloride. Friction force, which is the resistance force of the insect mass against the sum of centrifugal and tangential forces, was greater in heavier insects such as Er. tenax, M. florea and V. pellucens. Although lighter species generated lower frictional forces, the acceleration required to detach an insect was greater in smaller species. The area of attachment pads, setal tip area and setal density differed significantly in the species studied, and the dependence of these variables on body mass was significant. The frictional properties of the material of the setal tips were not dependent on the dimensions of the fly species. Similar results were obtained for the frictional properties of the pulvillus as a whole. Thus, the properties of the secretion and the mechanical properties of the material of the setal tips are approximately constant among the species studied. It is concluded that differences in friction force must be related mainly to variations in the real contact area generated by the pad on the smooth surface. The real contact area can be estimated as the summed area of the broadened setal tips of the pad in contact with the surface. The real contact area depends on such morphological variables as setal density and the area of a single setal tip. Although individual variables vary among flies with different dimensions, they usually compensate such that smaller setal tip area is partially compensated for by higher setal density.

scholarly journals An experimental study on the relation between friction force and real contact area

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
X. M. Liang ◽  
Y. Z. Xing ◽  
L. T. Li ◽  
W. K. Yuan ◽  
G. F. Wang
Keyword(s):  
Experimental Study ◽  
Friction Force ◽  
Contact Area ◽  
Linear Relation ◽  
Normal Load ◽  
Real Contact Area ◽  
Normal Loading ◽  
Real Contact ◽  
Loading And Unloading ◽  
Nominal Contact Area

AbstractClassical laws of friction suggest that friction force is proportional to the normal load and independent of the nominal contact area. As a great improvement in this subject, it is now widely accepted that friction force is proportional to the real contact area, and much work has been conducted based on this hypothesis. In present study, this hypothesis will be carefully revisited by measuring the friction force and real contact area in-site and real-time at both normal loading and unloading stages. Our experiments reveal that the linear relation always holds between friction force and normal load. However, for the relation between friction force and real contact area, the linearity holds only at the loading stage while fails at the unloading stage. This study may improve our understanding of the origin of friction.

Sliding on ice: Real contact area, melted film thickness, and friction force

2020 ◽  
Vol 160 ◽  
pp. 120166
Author(s):  
Changho Yun ◽  
Jin Woo Choi ◽  
Hyungseok Kim ◽  
Dongjo Kim ◽  
Ho-Young Kim
Keyword(s):  
Film Thickness ◽  
Friction Force ◽  
Contact Area ◽  
Real Contact Area ◽  
Real Contact

Influence of Paper Lint on Friction and Wear of Rubber Rollers

2018 ◽  
Author(s):  
Yosuke Tsukiyama ◽  
Isami Nitta
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Contact Area ◽  
Friction And Wear ◽  
Surface Contamination ◽  
Real Contact Area ◽  
The Real ◽  
Real Contact ◽  
Different Types

This paper deals with the influence of surface contamination on the frictional mechanisms of rubber rollers. The contamination which adhered on the rollers after feeding many sheets of papers is one of the predominant causes of paper jams. However, the mechanism has not been understood. The purpose of this paper is to clarify the relationships between the friction force and the real contact area of papers and contaminated rubber rollers. Carrying out paper feeding tests by using a commercial multifunction peripheral, we tested different types of papers produced by different manufacturers. The tests have been done with combinations of different manufacturer’s papers and different kinds of roller materials. Observations of the real contact area clarified that the roller surfaces covered with paper powders or lint reduces the friction coefficient.

scholarly journals Does Linearity Always Hold between Friction Force and Real Contact Area: An Experimental Study

2021 ◽  
Author(s):  
Xuan Ming Liang ◽  
Yuzhe Xing ◽  
Leitao Li ◽  
Weike Yuan ◽  
G.F. Wang
Keyword(s):  
Experimental Study ◽  
Friction Force ◽  
Contact Area ◽  
Normal Load ◽  
Real Contact Area ◽  
Normal Loading ◽  
Real Contact ◽  
Loading And Unloading ◽  
Nominal Contact Area ◽  
Real Area

Classical laws of friction suggest that friction force is proportional to the normal load and independent of the nominal contact area. As a great improvement in this subject, it is now widely accepted that friction force is proportional to the real area in contact, and much work has been conducted based on this hypothesis. In present study, this hypothesis will be carefully revisited by measuring the friction force and real contact area in-site and real-time at both normal loading and unloading stages. Our experiments reveal that the linear relation always holds between friction force and normal load. However, for the relation between friction force and real contact area, the linearity holds only at the loading stage while fails at the unloading stage. This study may improve our understanding of the origin of friction.

An Analytical Thermodynamic Approach to Friction of Rubber on Ice

2012 ◽  
Vol 40 (2) ◽  
pp. 124-150
Author(s):  
Klaus Wiese ◽  
Thiemo M. Kessel ◽  
Reinhard Mundl ◽  
Burkhard Wies
Keyword(s):  
Coefficient Of Friction ◽  
Liquid Layer ◽  
Contact Area ◽  
Leading Edge ◽  
Viscous Friction ◽  
Analytical Approximation ◽  
Real Contact Area ◽  
Length Scales ◽  
Real Contact ◽  
Ice Surface

ABSTRACT The presented investigation is motivated by the need for performance improvement in winter tires, based on the idea of innovative “functional” surfaces. Current tread design features focus on macroscopic length scales. The potential of microscopic surface effects for friction on wintery roads has not been considered extensively yet. We limit our considerations to length scales for which rubber is rough, in contrast to a perfectly smooth ice surface. Therefore we assume that the only source of frictional forces is the viscosity of a sheared intermediate thin liquid layer of melted ice. Rubber hysteresis and adhesion effects are considered to be negligible. The height of the liquid layer is driven by an equilibrium between the heat built up by viscous friction, energy consumption for phase transition between ice and water, and heat flow into the cold underlying ice. In addition, the microscopic “squeeze-out” phenomena of melted water resulting from rubber asperities are also taken into consideration. The size and microscopic real contact area of these asperities are derived from roughness parameters of the free rubber surface using Greenwood-Williamson contact theory and compared with the measured real contact area. The derived one-dimensional differential equation for the height of an averaged liquid layer is solved for stationary sliding by a piecewise analytical approximation. The frictional shear forces are deduced and integrated over the whole macroscopic contact area to result in a global coefficient of friction. The boundary condition at the leading edge of the contact area is prescribed by the height of a “quasi-liquid layer,” which already exists on the “free” ice surface. It turns out that this approach meets the measured coefficient of friction in the laboratory. More precisely, the calculated dependencies of the friction coefficient on ice temperature, sliding speed, and contact pressure are confirmed by measurements of a simple rubber block sample on artificial ice in the laboratory.

scholarly journals Relationship between the real contact behavior and tribological characteristics of cotton fabric

Friction ◽  
2020 ◽  
Author(s):  
Rongxin Chen ◽  
Jiaxin Ye ◽  
Wei Zhang ◽  
Jiang Wei ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Contact Area ◽  
Dynamic Change ◽  
Tribological Characteristics ◽  
Real Contact Area ◽  
Cotton Fibers ◽  
Friction Behavior ◽  
Contact Behavior ◽  
The Real ◽  
Real Contact

Abstract The tribological characteristics of cotton fibers play an important role in engineering and materials science, and real contact behavior is a significant aspect in the friction behavior of cotton fibers. In this study, the tribological characteristics of cotton fibers and their relationship with the real contact behavior are investigated through reciprocating linear tribotesting and real contact analysis. Results show that the friction coefficient decreases with a general increase in load or velocity, and the load and velocity exhibit a co-influence on the friction coefficient. The dynamic change in the real contact area is recorded clearly during the experiments and corresponds to the fluctuations observed in the friction coefficient. Moreover, the friction coefficient is positively correlated with the real contact area based on a quantitative analysis of the evolution of friction behavior and the real contact area at different loads and velocities. This correlation is evident at low velocities and medium load.

scholarly journals Estimation of real contact area during sliding friction from interface temperature

AIP Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 065227
Author(s):  
Sung Keun Chey ◽  
Pengyi Tian ◽  
Yu Tian
Keyword(s):  
Contact Area ◽  
Sliding Friction ◽  
Real Contact Area ◽  
Interface Temperature ◽  
Real Contact

An Observation Method of Real Contact Area during PVA Brush Scrubbing

2018 ◽  
Vol 282 ◽  
pp. 73-76 ◽  
Author(s):  
Toshiyuki Sanada ◽  
Masanao Hanai ◽  
Akira Fukunaga ◽  
Hirokuni Hiyama
Keyword(s):  
Contact Area ◽  
Contact Condition ◽  
Real Contact Area ◽  
Led Light ◽  
The Real ◽  
Real Contact ◽  
Observation Method

In the post CMP cleaning, the contact condition between PVA brush and surface is very important. In this study, we observed the real contact area between a brush and surface using a collimating LED light and prism. As a result, we found that the real contact area increases with increasing the brush compression. In addition, we also found that the real contact area decreases when the brush starts to move, and the brush was locally compressed due to its deformation.

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