Valentin L Popov – författare

This open access book gathers authoritative contributions concerning multiscale problems in biomechanics, geomechanics, materials science and tribology. It is written in memory of Sergey Grigorievich Psakhie to feature various aspects of his multifaceted research interests, ranging from theoretical physics, computer modeling of materials and material characterization at the atomic scale, to applications in space industry, medicine and geotectonics, and including organizational, psychological and philosophical aspects of scientific research and teaching as well. This book covers new advances relating to orthopedic implants, concerning the physiological, tribological and materials aspects of their behavior; medical and geological applications of permeable fluid-saturated materials; earthquake dynamics together with aspects relating to their managed and gentle release; lubrication, wear and material transfer in natural and artificial joints; material research in manufacturing processes; hard-soft matter interaction, including adhesive and capillary effects; using nanostructures for influencing living cells and for cancer treatment; manufacturing of surfaces with desired properties; self-organization of hierarchical structures during plastic deformation and thermal treatment; mechanics of composites and coatings; and many more. Covering established knowledge as well as new models and methods, this book provides readers with a comprehensive overview of the field, yet also with extensive details on each single topic.

This open access book gathers authoritative contributions concerning multiscale problems in biomechanics, geomechanics, materials science and tribology. It is written in memory of Sergey Grigorievich Psakhie to feature various aspects of his multifaceted research interests, ranging from theoretical physics, computer modeling of materials and material characterization at the atomic scale, to applications in space industry, medicine and geotectonics, and including organizational, psychological and philosophical aspects of scientific research and teaching as well. This book covers new advances relating to orthopedic implants, concerning the physiological, tribological and materials aspects of their behavior; medical and geological applications of permeable fluid-saturated materials; earthquake dynamics together with aspects relating to their managed and gentle release; lubrication, wear and material transfer in natural and artificial joints; material research in manufacturing processes; hard-soft matter interaction, including adhesive and capillary effects; using nanostructures for influencing living cells and for cancer treatment; manufacturing of surfaces with desired properties; self-organization of hierarchical structures during plastic deformation and thermal treatment; mechanics of composites and coatings; and many more. Covering established knowledge as well as new models and methods, this book provides readers with a comprehensive overview of the field, yet also with extensive details on each single topic.

Das Werk beschreibt erstmalig in einer geschlossenen Form eine Simulationsmethode zur schnellen Berechnung von Kontakteigenschaften und Reibung zwischen rauen Oberflächen. Im Unterschied zu bestehenden Simulationsverfahren basiert die Methode der Dimensionsreduktion (MDR) auf einer exakten Abbildung verschiedener Klassen von dreidimensionalen Kontaktproblemen auf Kontakte mit eindimensionalen Bettungen. Innerhalb der MDR wird jedoch nicht nur die Dimension von drei auf eins reduziert, sondern gleichermaßen sind voneinander unabhängige Freiheitsgrade gegeben. Die MDR beinhaltet daher eine enorme Reduktion sowohl der Entwicklungszeit für die numerische Implementierung von Kontaktproblemen als auch der direkten Rechenzeit und kann letztlich in der Tribologie eine ähnliche Rolle einnehmen wie FEM in der Strukturmechanik oder bekannte CFD-Löser in der Hydrodynamik. Darüber hinaus erleichtert sie in hohem Maße analytische Berechnungen und bietet eine Art “Taschenausgabe” dergesamten Kontaktmechanik. Messungen der Rheologie der kontaktierenden Körper sowie ihrer Oberflächentopographie und Adhäsionseigenschaften finden unmittelbaren Eingang in die Berechnung. Insbesondere ist es möglich, die gesamte Dynamik des Systems – beginnend mit der makroskopischen Systemdynamik über die makroskopische, dynamische Kontaktberechnung bis hin zum Einfluss der Rauheit – in einem numerischen Simulationsmodell zu erfassen. Die MDR erlaubt demnach die Vereinigung der charakteristischen Abläufe verschiedener Skalen. Zielsetzung des Buches ist es, einerseits die Berechtigung und Zuverlässigkeit der Methode zu belegen, andererseits ihre äußerst einfache Handhabung interessierten Praktikern zu erklären.

This book describes for the first time a simulation method for the fast calculation of contact properties and friction between rough surfaces in a complete form. In contrast to existing simulation methods, the method of dimensionality reduction (MDR) is based on the exact mapping of various types of three-dimensional contact problems onto contacts of one-dimensional foundations. Within the confines of MDR, not only are three dimensional systems reduced to one-dimensional, but also the resulting degrees of freedom are independent from another. Therefore, MDR results in an enormous reduction of the development time for the numerical implementation of contact problems as well as the direct computation time and can ultimately assume a similar role in tribology as FEM has in structure mechanics or CFD methods, in hydrodynamics. Furthermore, it substantially simplifies analytical calculation and presents a sort of “pocket book edition” of the entirety contact mechanics. Measurements of the rheology of bodies in contact as well as their surface topography and adhesive properties are the inputs of the calculations. In particular, it is possible to capture the entire dynamics of a system – beginning with the macroscopic, dynamic contact calculation all the way down to the influence of roughness – in a single numerical simulation model. Accordingly, MDR allows for the unification of the methods of solving contact problems on different scales. The goals of this book are on the one hand, to prove the applicability and reliability of the method and on the other hand, to explain its extremely simple application to those interested.

Das anwendungsorientierte Buch führt in den Zusammenhang von Kontaktmechanik und Reibung ein und ermöglicht damit ein tieferes Verständnis der Tribologie.

This book describes for the first time a simulation method for the fast calculation of contact properties and friction between rough surfaces in a complete form. In contrast to existing simulation methods, the method of dimensionality reduction (MDR) is based on the exact mapping of various types of three-dimensional contact problems onto contacts of one-dimensional foundations. Within the confines of MDR, not only are three dimensional systems reduced to one-dimensional, but also the resulting degrees of freedom are independent from another. Therefore, MDR results in an enormous reduction of the development time for the numerical implementation of contact problems as well as the direct computation time and can ultimately assume a similar role in tribology as FEM has in structure mechanics or CFD methods, in hydrodynamics. Furthermore, it substantially simplifies analytical calculation and presents a sort of “pocket book edition” of the entirety contact mechanics. Measurements of the rheology of bodies in contact as well as their surface topography and adhesive properties are the inputs of the calculations. In particular, it is possible to capture the entire dynamics of a system – beginning with the macroscopic, dynamic contact calculation all the way down to the influence of roughness – in a single numerical simulation model. Accordingly, MDR allows for the unification of the methods of solving contact problems on different scales. The goals of this book are on the one hand, to prove the applicability and reliability of the method and on the other hand, to explain its extremely simple application to those interested.

Das Buch beinhaltet eine strukturierte Sammlung der vollständigen Lösungen aller wesentlichen axialsymmetrischen Kontaktprobleme. Es werden Lösungen für klassische Profile wie die Kugel, den Kegel oder den flachen zylindrischen Stempel angegeben, aber auch für eine Vielzahl weiterer technisch relevanter Formen, z.B. den Kegelstumpf, den Zylinder mit abgerundeten Rändern, die verschlissene Kugel, Profile mit Welligkeit, Hohlzylinder usw. Behandelt werden Normal-, Tangential- und Torsionskontakte -, sowohl adhäsionsfreie als auch adhäsionsbehaftete. Als Medien kommen elastisch isotrope, transversal isotrope, viskoelastische sowie funktionale Gradientenwerkstoffe zur Sprache. Die Lösungen der Kontaktprobleme umfassen neben den Zusammenhängen zwischen den makroskopischen Kraft- und Verschiebungsgrößen sowie der Kontaktkonfiguration auch die Spannungs- und Verschiebungsfelder an der Oberfläche und gegebenenfalls innerhalb des Halbraum-Mediums. Lösungen werden immer mit der jeweils einfachsten zur Verfügung stehenden Methode gewonnen – meistens mit der Methode der Dimensionsreduktion oder Ansätzen zur Rückführung des jeweiligen Kontaktproblems auf das nicht-adhäsive Normalkontaktproblem.Die ZielgruppenDas Buch wendet sich an Berechnungsingenieure in der Industrie wie z.B. Maschinenbau, Reifenindustrie, Automobilindustrie, Polymer- und Elastomerhersteller. Zugleich dient es als Nachschlagewerk in Forschung und Lehre.

This application-oriented book introduces readers to the associations and relationships between contact mechanics and friction, providing them with a deeper understanding of tribology. It addresses the related phenomena of contacts, adhesion, capillary forces, friction, lubrication, and wear from a consistent point of view. The author presents (1) methods for rough estimates of tribological quantities, (2) simple and general methods for analytical calculations, and (3) the crossover into numerical simulation methods, the goal being to convey a consistent view of tribological processes at various scales of magnitude (from nanotribology to earthquake research).The book also explores the system dynamic aspects of tribological systems, such as squeal and its suppression, as well as other types of instabilities and spatial patterns. It includes problems and worked-out solutions for the respective chapters, giving readers ample opportunity to apply the theory to practical situations and to deepen their understanding of the material discussed.The second edition has been extended with a more detailed exposition of elastohydrodynamic lubrication, an updated chapter on numerical simulation methods in contact mechanics, a new section on fretting in the chapter on wear, as well as numerous new exercises and examples, which help to make the book an excellent reference guide.

This application-oriented book introduces readers to the associations and relationships between contact mechanics and friction, providing them with a deeper understanding of tribology. It addresses the related phenomena of contacts, adhesion, capillary forces, friction, lubrication, and wear from a consistent point of view. The author presents (1) methods for rough estimates of tribological quantities, (2) simple and general methods for analytical calculations, and (3) the crossover into numerical simulation methods, the goal being to convey a consistent view of tribological processes at various scales of magnitude (from nanotribology to earthquake research).The book also explores the system dynamic aspects of tribological systems, such as squeal and its suppression, as well as other types of instabilities and spatial patterns. It includes problems and worked-out solutions for the respective chapters, giving readers ample opportunity to apply the theory to practical situations and to deepen their understanding of the material discussed.The second edition has been extended with a more detailed exposition of elastohydrodynamic lubrication, an updated chapter on numerical simulation methods in contact mechanics, a new section on fretting in the chapter on wear, as well as numerous new exercises and examples, which help to make the book an excellent reference guide.

Based on a systematic distinction regarding the type of contact, the regime of friction and the contact geometry, a multitude of technically relevant contact problems from mechanical engineering, the automotive industry and medical engineering are discussed.

Das Buch beinhaltet eine strukturierte Sammlung der vollständigen Lösungen aller wesentlichen ebenen Kontaktprobleme. Es werden klassische Profile – wie der Zylinder, der Keil oder der quaderförmige flache Stempel – unter zentrischer und exzentrischer Belastung behandelt, aber auch eine Vielzahl weiterer technisch relevanter Formen, wie der flache Stempel mit abgerundeten Kanten, der Keil mit abgerundeter Spitze oder wellige Oberflächen. In Bezug auf die Lastkonfiguration werden adhäsive und adhäsionsfreie Normalkontakte, Tangentialkontakte und Rollkontakte berücksichtigt. Als Materialien kommen elastisch isotrope, transversal isotrope, viskoelastische und funktionale Gradientenmedien zur Sprache. Die angegebenen Lösungen werden jeweils auf dem einfachsten zur Verfügung stehenden Weg hergeleitet und umfassen neben den makroskopischen Zusammenhängen zwischen der Last und der Kontaktkonfiguration die Spannungsfelder in der Oberfläche und gegebenenfalls innerhalb der Kontaktkörper.

With regard to the load configuration, adhesive and non-adhesive normal contacts, tangential contacts, and rolling contacts are considered.