[...]... of contact mechanics and friction is ultimately about our ability to control friction, adhesion, and wear and to mould them to our wishes For that, a detailed understanding of the dependency of contact, friction, and wear phenomena on the materials and system properties is necessary 1.2 History of Contact Mechanics and the Physics of Friction 3 1.2 History of Contact Mechanics and the Physics of Friction. .. are examples of frictional contacts as well Contact and friction phenomena on different scales, from nanoscale phenomena to those on a mega-scale, have much in common and, thus, can be approached with similar methods Contact mechanics and the physics V.L Popov, Contact Mechanics and Friction, DOI 10.1007/978-3-642-10803-7_1, © Springer- Verlag Berlin Heidelberg 2010 2 1 Introduction of friction has proven... 7 1.3 Structure of the Book Contact and friction always go hand in hand and are interlaced in many ways in real systems In our theoretical treatment, we must first separate them We begin our investigation of contact and frictional phenomena with contact mechanics This, in turn, begins with a qualitative analysis, which provides us with a simple, but comprehensive understanding of the respective phenomena... ultrasonic welding, electrical contacts, and many others These applications have tasks spanning from stress analysis of contact elements and joints, over the influence of lubrication and material design on friction and wear, to applications in micro and nanotechnology Friction is a phenomenon that people have been interested in for over hundreds and even thousands of years and still today remains in the middle... normal contact should deliver are: (1) The relationship between the contact force and the normal displacement of the body, which determines the stiffness of the contact and therefore the dynamic properties of the system (2) The relationships between forces and contact stresses and whether or not they exceed the critical values Without actual geometric contact there can be no other contact phenomena, no friction, ... events happening in the contact area during rolling contact and established that on a driven wheel, there are always areas in which the two bodies are in no-slip contact and areas where slipping takes place It was the first attempt to put tribological contact underneath a magnifying glass and at the same time the end of the strict differentiation between static friction and kinetic friction Reynolds accounted... M Popov and Dr G Putzar for their help with proofreading I thank the Dean of Faculty V, Transportation and Machine Systems, for granting me a research semester, during which this book was completed Berlin, October 2008 V.L Popov Table of Contents 1 Introduction 1 1.1 Contact and Friction Phenomena and their Applications 1 1.2 History of Contact Mechanics and the Physics of Friction. .. will delve into the rigorous treatment of contact problems and subsequently move on to frictional phenomena, lubrication, and wear 2 Qualitative Treatment of Contact Problems – Normal Contact without Adhesion We begin our consideration of contact problems with the normal contact problem A normal contact problem revolves around two bodies which are brought into contact with one another by forces perpendicular... invented, and the composition of a low -friction alloy as well his experimental examination of friction and wear phenomena He was the first engineer who persistently and quantitatively formulated the laws of friction He arrived at the conclusion that can be summarized in today’s language as two fundamental Laws of Friction: 1 The frictional force is proportional to the normal force, or load 2 The frictional... frictional forces pre- V.L Popov, Contact Mechanics and Friction, DOI 10.1007/978-3-642-10803-7_2, © Springer- Verlag Berlin Heidelberg 2010 10 2 Qualitative Treatment of Contact Problems – Normal Contact without Adhesion sent in the contact area Also, the always present attractive force, adhesion, will be neglected for the time being An analytical or numerical analysis of contact problems is even in the .