Friction

2019 ◽  
pp. 88-109
Author(s):  
C. Mathew Mate ◽  
Robert W. Carpick
Keyword(s):  
Static Friction ◽  
Kinetic Friction ◽  
Stick Slip ◽  
Sliding Surfaces ◽  
Proportionality Constant ◽  
Contact Points ◽  
Real Area Of Contact ◽  
Stick Slip Motion ◽  
Slip Motion ◽  
Slip Distance

This chapter introduces friction as it manifests itself in everyday life. The chapter begins with Amontons’ law (1699) that friction is proportional to the loading force between contacting surfaces (the proportionality constant is called the coefficient of friction). The two primary mechanisms for unlubricated friction are adhesive friction and plowing friction, with the predominant mechanism generally being adhesive friction. Adhesive friction is proportional to the real area of contact; for rough surfaces, this contact area is proportional to the loading force, providing a physical underpinning for Amontons’ law. Processes like the nanoscale flow of atoms and molecules around contact points results in the force needed to induce sliding (static friction) being higher than the force needed to maintain sliding (kinetic friction). Friction decreasing with increasing velocity leads stick-slip motion of the sliding surfaces, where the slip distance can be as short as the distance between atoms.

Stick-Slip Motion of Machine Tool Slideway

1974 ◽  
Vol 96 (2) ◽  
pp. 557-566 ◽  
Author(s):  
S. Kato ◽  
K. Yamaguchi ◽  
T. Matsubayashi
Keyword(s):  
Boundary Conditions ◽  
Machine Tool ◽  
Static Friction ◽  
Experimental Results ◽  
Kinetic Friction ◽  
Stick Slip ◽  
Frictional Coefficients ◽  
Stick Slip Motion ◽  
Slip Motion

Stick-slip motion of a moving element on an actual machine tool slideway is investigated experimentally under various sliding conditions, and the fundamental characteristics of the stick-slip motion are clarified. Based on these experimental results, the characteristics of static friction in the period of stick and kinetic friction in the period of slip are studied concretely so as to clarify the stick-slip process. It is shown experimentally that static and kinetic frictional coefficients can be expressed with simple formulas. Using these expressions, the boundary conditions for occurrence of stick-slip motion are examined, and the relation between properties of the stick-slip motion and frictional characteristics is explained quantitatively.

Some Considerations on Characteristics of Static Friction of Machine Tool Slideway

1972 ◽  
Vol 94 (3) ◽  
pp. 234-247 ◽  
Author(s):  
S. Kato ◽  
N. Sato ◽  
T. Matsubayashi
Keyword(s):  
Machine Tool ◽  
Time Dependence ◽  
Surface Topography ◽  
Empirical Formula ◽  
Great Influence ◽  
Static Friction ◽  
Stick Slip ◽  
Stick Slip Motion ◽  
Influence Of Properties ◽  
Slip Motion

The fundamental characteristics of “stick-slip” motion in a machine tool slideway is ascertained experimentally, and it is clarified that the time-dependence of static friction has a great influence on the behavior of the stick-slip motion. An empirical formula is proposed to express the characteristics of static friction and the mechanism of the time-dependence of static friction is examined experimentally and theoretically. The influence of properties of lubricants and surface topography on the static friction is investigated quantitatively. Finally, a general conception to prevent stick-slip motion is offered.

Stick-Slip Motion of Frictionally Damped Turbine Airfoils: A Finite Element in Time (FET) Approach

1997 ◽  
Vol 119 (2) ◽  
pp. 236-242 ◽  
Author(s):  
Yu Wang
Keyword(s):  
Turbine Blades ◽  
Static Friction ◽  
Response Analysis ◽  
Stick Slip ◽  
System Equations ◽  
Structured System ◽  
The Time Domain ◽  
Turbine Airfoils ◽  
Stick Slip Motion ◽  
Slip Motion

A method is proposed for analyzing the periodic stick-slip motion of a single degree of freedom model of frictionally damped turbine blades. The method of finite elements in the time domain (FET) is based on a Hamilton’s weak principle, paralleling the variational methods in elastostatics. It permits a complete determination of the hysteretic friction force, and results in a set of highly structured system equations. The method has a number of unique features, which are utilized to provide a simple yet efficient approach for predicting the steady-state response. When applied to a number of example problems, including systems with static friction and the excitation of multiple discrete frequencies, the FET method is demonstrated to be an efficient and reliable alternative technique for nonlinear dynamic response analysis.

Stick–Slip Motion and Static Friction in a Nonlinear Deformable Substrate Potential

2011 ◽  
Vol 43 (1) ◽  
pp. 65-72 ◽  
Author(s):  
M. Motchongom-Tingue ◽  
G. Djuidjé Kenmoé ◽  
T. C. Kofané
Keyword(s):  
Static Friction ◽  
Stick Slip ◽  
Substrate Potential ◽  
Stick Slip Motion ◽  
Slip Motion
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