Quoting the classical K.L. Johnson's book on Contact Mechanics (Cambridge University Press, Cambridge, 1985), contact mechanics "is concerned with the stresses and deformation which arise when the surfaces of two solid bodies are brought into contact". This definition is sufficiently broad to include surface roughness, different deformation modes and the occurrence of non-conformal contacts. Therefore contact mechanics appears to be a complex subject, posing challenging questions on materials science, solid-state physics and surface science, with serious and profound implications on tribology. In the 1900s the school of Bowden and Tabor has performed systematic experiments on the macroscale, introducing the fruitful concepts of real area of contact and of contact asperities. Within the last 20 years novel experimental techniques have allowed to directly access static and dynamic properties of isolated asperities: particularly the Atomic Force Microscope (AFM), studying deformation and dissipation phenomena in micro/nano-sized junctions, and the Quartz Crystal Microbalance (QCM), providing deeper insight on the elemental dissipation mechanisms. On the theoretical side, molecular dynamics simulations have opened up the possibility to explore deformation and dissipation phenomena down to the atomic scale with unbelievable predictive capability. These approaches have led to the growth of a new field, called nanotribology, within which contact mechanics is still playing a pivotal role. The appearance of a whole phenomenology of contact phenomena at the micro- and nano-scale is now providing considerable benefits also to the macroscopic counterpart of contact mechanics, stimulating attempts to bridge the gap between the macro- and the nano-scale: this process, still largely undefined at present, demands a critical revision of past concepts towards a possible unifying theory of contact phenomena. The present book is an attempt to cover the most recent developments in the fields of theoretical and experimental contact mechanics: we selected subjects that appear to be scale-independent and good candidates for a universal phenomenological description. We also included sections proving the importance of contact mechanics arguments for applied materials science, coatings technology, biomaterials characterization and tissue engineering. The following topics are deeply explored: continuum modelling of multi-scale rough interfaces under elasto-plastic deformation conditions (Chapters 1, 2); atomistic modelling of brittle fracture (Chapter 3) and elemental dissipation mechanisms in sliding friction (Chapters 4); contact mechanics, friction and adhesion of rubber-like materials (Chapter 5, 6); nanoscale and mesoscale phenomenology of contact mechanics and friction, probed by AFM (Chapters 7, 8) and QCM (Chapter 9); technological challenges in protective coatings and biomaterials (Chapters 10,11); phenomenology and theory of tribochemical reactions (Chapter 12). We would like to express appreciation and thank to our colleagues, kindly accepting to contribute to this volume, to the Italian Ministry of University and Research MIUR, supporting contact mechanics research with the two-years PRIN project "Nanotribology", and to the European Science Foundation ESF programme "Natribo", improving collaboration and research on nanotribology within the European area. Our sincere thanks are for Dr. S.G. Pandalai, assisting us in the editing process, and for Transworld Research Network, proving us such an invaluable opportunity.
Advances in Contact Mechanics: Implications for Materials Science, Engineering and Biology
Renato Buzio;
2007
Abstract
Quoting the classical K.L. Johnson's book on Contact Mechanics (Cambridge University Press, Cambridge, 1985), contact mechanics "is concerned with the stresses and deformation which arise when the surfaces of two solid bodies are brought into contact". This definition is sufficiently broad to include surface roughness, different deformation modes and the occurrence of non-conformal contacts. Therefore contact mechanics appears to be a complex subject, posing challenging questions on materials science, solid-state physics and surface science, with serious and profound implications on tribology. In the 1900s the school of Bowden and Tabor has performed systematic experiments on the macroscale, introducing the fruitful concepts of real area of contact and of contact asperities. Within the last 20 years novel experimental techniques have allowed to directly access static and dynamic properties of isolated asperities: particularly the Atomic Force Microscope (AFM), studying deformation and dissipation phenomena in micro/nano-sized junctions, and the Quartz Crystal Microbalance (QCM), providing deeper insight on the elemental dissipation mechanisms. On the theoretical side, molecular dynamics simulations have opened up the possibility to explore deformation and dissipation phenomena down to the atomic scale with unbelievable predictive capability. These approaches have led to the growth of a new field, called nanotribology, within which contact mechanics is still playing a pivotal role. The appearance of a whole phenomenology of contact phenomena at the micro- and nano-scale is now providing considerable benefits also to the macroscopic counterpart of contact mechanics, stimulating attempts to bridge the gap between the macro- and the nano-scale: this process, still largely undefined at present, demands a critical revision of past concepts towards a possible unifying theory of contact phenomena. The present book is an attempt to cover the most recent developments in the fields of theoretical and experimental contact mechanics: we selected subjects that appear to be scale-independent and good candidates for a universal phenomenological description. We also included sections proving the importance of contact mechanics arguments for applied materials science, coatings technology, biomaterials characterization and tissue engineering. The following topics are deeply explored: continuum modelling of multi-scale rough interfaces under elasto-plastic deformation conditions (Chapters 1, 2); atomistic modelling of brittle fracture (Chapter 3) and elemental dissipation mechanisms in sliding friction (Chapters 4); contact mechanics, friction and adhesion of rubber-like materials (Chapter 5, 6); nanoscale and mesoscale phenomenology of contact mechanics and friction, probed by AFM (Chapters 7, 8) and QCM (Chapter 9); technological challenges in protective coatings and biomaterials (Chapters 10,11); phenomenology and theory of tribochemical reactions (Chapter 12). We would like to express appreciation and thank to our colleagues, kindly accepting to contribute to this volume, to the Italian Ministry of University and Research MIUR, supporting contact mechanics research with the two-years PRIN project "Nanotribology", and to the European Science Foundation ESF programme "Natribo", improving collaboration and research on nanotribology within the European area. Our sincere thanks are for Dr. S.G. Pandalai, assisting us in the editing process, and for Transworld Research Network, proving us such an invaluable opportunity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
