Author: J.A.C. Martinis
Publisher: Springer Science & Business Media
ISBN: 9783211836958
Category : Science
Languages : en
Pages : 304
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Book Description
The book addresses instability and bifurcation phenomena in frictional contact problems. The treatment of this subject has its roots in previous studies of instability and bifurcation in elastic, thermoelastic or elastic-plastic bodies, and in previous mathematical, mechanical and computational studies of unilateral problems. The salient feature of this book is to put together and develop concepts and tools for stability and bifurcation studies in mechanics, taking into account the inherent non-smoothness and non-associativity (non-symmetry) of unilateral frictional contact laws. The mechanical foundations, the mathematical theory and the computational algorithms for such studies are developed along six chapters written by the lecturers of a CISM course. Those concepts and tools are illustrated not only with enlightening academic examples but also with some demanding industrial applications, related, namely, to the automotive industry.
Author: Bharat Bhushan
Publisher: Springer Science & Business Media
ISBN: 9401150508
Category : Science
Languages : en
Pages : 652
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Book Description
Micro Electro Mechanical Systems (MEMS) is already about a billion dollars a year industry and is growing rapidly. So far major emphasis has been placed on the fabrication processes for various devices. There are serious issues related to tribology, mechanics, surfacechemistry and materials science in the operationand manufacturingof many MEMS devices and these issues are preventing an even faster commercialization. Very little is understood about tribology and mechanical properties on micro- to nanoscales of the materials used in the construction of MEMS devices. The MEMS community needs to be exposed to the state-of-the-artoftribology and vice versa. Fundamental understanding of friction/stiction, wear and the role of surface contamination and environmental debris in micro devices is required. There are significantadhesion, friction and wear issues in manufacturing and actual use, facing the MEMS industry. Very little is understood about the tribology of bulk silicon and polysilicon films used in the construction ofthese microdevices. These issues are based on surface phenomenaand cannotbe scaled down linearly and these become increasingly important with the small size of the devices. Continuum theory breaks down in the analyses, e. g. in fluid flow of micro-scale devices. Mechanical properties ofpolysilicon and other films are not well characterized. Roughness optimization can help in tribological improvements. Monolayers of lubricants and other materials need to be developed for ultra-low friction and near zero wear. Hard coatings and ion implantation techniques hold promise.
Author: Michael Nosonovsky
Publisher: CRC Press
ISBN: 1466504048
Category : Science
Languages : en
Pages : 332
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Book Description
Many scientists and engineers do not realize that, under certain conditions, friction can lead to the formation of new structures at the interface, including in situ tribofilms and various patterns. In turn, these structures-usually formed by destabilization of the stationary sliding regime-can lead to the reduction of friction and wear. Friction-I
Author: J.F. Labuz
Publisher: CRC Press
ISBN: 9789058095633
Category : Technology & Engineering
Languages : en
Pages : 282
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Book Description
This book contains a sampling of papers presented at the June 2-5, 2002 International Workshop on Bifurcations andamp; Instabilities in Geomechanics (IWBI 2002). The scope of the Workshop includes analytical approaches, numerical methods, and experimental techniques.
Author: J.A.C. Martinis
Publisher: Springer
ISBN: 3709125340
Category : Science
Languages : en
Pages : 297
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Book Description
The book addresses instability and bifurcation phenomena in frictional contact problems. The treatment of this subject has its roots in previous studies of instability and bifurcation in elastic, thermoelastic or elastic-plastic bodies, and in previous mathematical, mechanical and computational studies of unilateral problems. The salient feature of this book is to put together and develop concepts and tools for stability and bifurcation studies in mechanics, taking into account the inherent non-smoothness and non-associativity (non-symmetry) of unilateral frictional contact laws. The mechanical foundations, the mathematical theory and the computational algorithms for such studies are developed along six chapters written by the lecturers of a CISM course. Those concepts and tools are illustrated not only with enlightening academic examples but also with some demanding industrial applications, related, namely, to the automotive industry.
Author: D.A. Hills
Publisher: Springer Science & Business Media
ISBN: 9401582815
Category : Technology & Engineering
Languages : en
Pages : 251
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Book Description
Failures of many mechanical components in service result from fatigue. The cracks which grow may either originate from some pre-existing macroscopic defect, or, if the component is of high integrity but highly stressed, a region of localized stress concentration. In turn, such concentrators may be caused by some minute defect, such as a tiny inclusion, or inadvertent machining damage. Another source of surface damage which may exist between notionally 'bonded' components is associated with minute relative motion along the interface, brought about usually be cyclic tangential loading. Such fretting damage is quite insidious, and may lead to many kinds of problems such as wear, but it is its influence on the promotion of embryo cracks with which we are concerned here. When the presence of fretting is associated with decreased fatigue performance the effect is known as fretting fatigue. Fretting fatigue is a subject drawing equally on materials science and applied mechanics, but it is the intention in this book to concentrate attention entirely on the latter aspects, in a search for the quantification of the influence of fretting on both crack nucleation and propagation. There have been very few previous texts in this area, and the present volume seeks to cover five principal areas; (a) The modelling of contact problems including partial slip under tangentialloading, which produces the surface damage. (b) The modelling of short cracks by rigorous methods which deal effectively with steep stress gradients, kinking and closure. (c) The experimental simulation of fretting fatigue.
Author: Orang Vahid-Araghi
Publisher: Springer Science & Business Media
ISBN: 1441917527
Category : Technology & Engineering
Languages : en
Pages : 220
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Book Description
Friction-Induced Vibration in Lead Screw Drives covers the dynamics of lead screw drives with an emphasis on the role of friction. Friction-induced vibration in lead screws can be the cause of unacceptably high levels of audible noise as well as loss of operation accuracy and shortened life. Although lead screw drives have a long history and their mechanical design and manufacturing aspects are very well understood, the role of friction in their dynamical behavior has not been comprehensively treated. The book draws on the vast body of work on the subject of dynamical systems with friction (such as disk brake systems) and offers said treatment, along with: · Unique coverage of modeling of multi-DOF lead screw systems with friction · Detailed analysis of negative damping, mode coupling, and kinematic constraint instability mechanisms in lead screws drives · A practical parameter identification approach for the velocity dependent coefficient of friction in lead screw drives Friction-Induced Vibration in Lead Screw Drives serves as the definitive text on the friction-induced vibration of lead screws, and includes a practical case study where the developed methods are used to study the excessive noise problem of a lead screw drive system and to put forward design modifications that eliminate the friction-induced vibrations.
Author: I.L. Singer
Publisher: Springer Science & Business Media
ISBN: 9401128111
Category : Science
Languages : en
Pages : 638
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Book Description
Fundamentals of Friction, unlike many books on tribology, is devoted to one specific topic: friction. After introductory chapters on scientific and engineering perspectives, the next section contains the necessary background within the areas of contact mechanics, surfaces and adhesion. Then on to fracture, deformation and interface shear, from the macroscopic behavior of materials in frictional contact to microscopic models of uniform and granular interfaces. Lubrication by solids, liquids and gases is presented next, from classical flow properties to the reorganization of monolayers of molecules under normal and shear stresses. A section on new approaches at the nano- and atomic scales covers the physics and chemistry of interfaces, an array of visually exciting simulations, using molecular dynamics, of solids and liquids in sliding contact, and related AFM/STM studies. Following a section on machines and measurements, the final chapter discusses future issues in friction.
Author: O. Mahrenholtz
Publisher: Springer
ISBN: 3709128129
Category : Technology & Engineering
Languages : en
Pages : 501
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Book Description
Author: Bo N.J. Persson
Publisher: Springer Science & Business Media
ISBN: 3662036460
Category : Science
Languages : en
Pages : 465
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Book Description
Sliding friction is one of the oldest problems in physics and certainly one of the most important from a practical point of view. The ability to produce durable low-friction surfaces and lubricant fluids has become an important factor in the miniaturization of moving components in many technological devices, e.g., magnetic storage, recording systems, miniature motors and many aerospace components. This book will be useful to physicists, chemists, materials scientists, and engineers who want to understand sliding friction. The book (or parts of it) could also form the basis for a modern undergraduate or graduate course on tribology.
