Tomasz Sadowski - Böcker

The IUTAM Symposium on “Multiscale Modelling of Damage and Fracture Processes in Composite Materials” was held in Kazimierz Dolny, Poland , 23 -27 May 2005. The Symposium was attended by 48 persons from 15 countries. During 5 day meeting, 4 keynote lectures and 39 invited lectures were presented. This volume constitutes the Proceedings of the IUTAM Symposium. The main aim of the Symposium was to discuss the basic principles of damage growth and fracture processes in different types of composites: ceramic, polymer and metal matrix composites, cement and bituminous composites and wood. Nowadays, it is widely recognized that important macroscopic properties like the macroscopic stiffness and strength, are governed by processes that occur at one to several scales below the level of observation starting from nanoscale. Understanding how these processes influence the reduction of stiffness and strength is essential for the analysis of existing and the design of improved composite materials. The study of how these various length scales can be linked together or taken into account simultaneously is particular attractive for composite materials, since they have a well-defined structure at the nano, micro and meso-levels. The well-defined microstructural level can be associated with small particles or fibres, while the individual laminae can be indentified at the mesoscopic level. Moreover, the advances in multiscale modelling of damage and fracture processes to the description of the complete constitutive behaviour in composites which do not have a very well-defined microstructure, e.g. cementitious, bitumous composites and wood was analysed.

This book presents the latest achievements in the field of composite materials modelling presented by the following authors: (1) Prof. H. Altenbach (Germany), (2) Prof. R. de Borst (The Netherlands), (3) prof. E. Craciun (Romania), (4) Prof. R. Pyrz (Denmark), (5) Prof. T.Sadowski (Poland). The text gives a modern, up-to-date account of recent developments in the modelling of composite materials. Multiscale concepts, which are the new paradigm in (computational) mechanics, are at the heart of this text, and are treated in detail in the first three chapters of the book. Other relevant developments are covered in the later chapters of the book, beginning with the most relevant issue of coupling stress analysis and diffusion phenomena that arise from hygral and/or thermal loading, which are of crucial importance of the short and long-term resistance of composite materials. The volume facilitates understanding of the basic principles of damage growth and fracture processes in various composite materials, including ceramics, polymers, metal-matrix composites and porous materials.

Both computational and experimental aspects play a central role, and talks have also focused on a broad range of aspects either related to the material modelling or the structural one. Various types of complex materials, made of very different constituents, are used nowadays in engineering practice: particle or fibrous composites;

Various types of composites are used in engineering practice. The most important are fibrous compositesy laminates and materials with a more complicated geometry of reinforcement in the form of short fibres and particles of various properties^ shapes and sizes. The aim of course was to understand the basic principles of damage growth and fracture processes in ceramic, polymer and metal matrix composites. Nowadays, it is widely recognized that important macroscopic properties like the macroscopic stiffness and strength, are governed by processes that occur at one to several scales below the level of observation. Understanding how these processes infiuence the reduction of stiffness and strength is essential for the analysis of existing and the design of improved composite materials. The study of how these various length scales can be linked together or taken into account simultaneously is particular attractive for composite materials, since they have a well-defined structure at the micro and meso-levels. Moreover, the microstructural and mesostructural levels are well-defined: the microstructural level can be associated with small particles or fibres, while the individual laminae can be indentified at the mesoscopic level. For this reason, advances in multiscale modelling and analysis made here, pertain directly to classes of materials which either have a range of relevant microstructural scales, such as metals, or do not have a very we- defined microstructure, e.g. cementitious composites. In particular, the fracture mechanics and optimization techniques for the design of polymer composite laminates against the delamination type of failure was discussed.

This short book describes the basic technological aspects involved in the creation of purely clinch and clinch-adhesive joints made of different types of adherent materials and employing different joining technologies.

The papers in this volume deal with materials science, theoretical mechanics and experimental and computational techniques at multiple scales, providing a sound base and a framework for many applications which are hitherto treated in a phenomenological sense. The basic principles are formulated of multiscale modeling strategies towards modern complex multiphase materials subjected to various types of mechanical, thermal loadings and environmental effects. The focus is on problems where mechanics is highly coupled with other concurrent physical phenomena. Attention is also focused on the historical origins of multiscale modeling and foundations of continuum mechanics currently adopted to model non-classical continua with substructure, for which internal length scales play a crucial role.

The papers in this volume present basic concepts and new developments in failure and damage analysis with focus on advanced materials such as composites, laminates, sandwiches and foams, and also new metallic materials. Starting from some mathematical foundations (limit surfaces, symmetry considerations, invariants) new experimental results and their analysis are shown. Finally, new concepts for failure prediction and analysis will be introduced and discussed as well as new methods of failure and damage prediction for advanced metallic and non-metallic materials. Based on experimental results the traditional methods will be revised.

The IUTAM Symposium on “Multiscale Modelling of Damage and Fracture Processes in Composite Materials” was held in Kazimierz Dolny, Poland , 23 -27 May 2005. The Symposium was attended by 48 persons from 15 countries. During 5 day meeting, 4 keynote lectures and 39 invited lectures were presented. This volume constitutes the Proceedings of the IUTAM Symposium. The main aim of the Symposium was to discuss the basic principles of damage growth and fracture processes in different types of composites: ceramic, polymer and metal matrix composites, cement and bituminous composites and wood. Nowadays, it is widely recognized that important macroscopic properties like the macroscopic stiffness and strength, are governed by processes that occur at one to several scales below the level of observation starting from nanoscale. Understanding how these processes influence the reduction of stiffness and strength is essential for the analysis of existing and the design of improved composite materials. The study of how these various length scales can be linked together or taken into account simultaneously is particular attractive for composite materials, since they have a well-defined structure at the nano, micro and meso-levels. The well-defined microstructural level can be associated with small particles or fibres, while the individual laminae can be indentified at the mesoscopic level. Moreover, the advances in multiscale modelling of damage and fracture processes to the description of the complete constitutive behaviour in composites which do not have a very well-defined microstructure, e.g. cementitious, bitumous composites and wood was analysed.

Composite materials are heterogeneous by nature, and are intended to be, since only the combination of different constituent materials can give them the desired combination of low weight, stiffness and strength. At present, the knowledge has advanced to a level that materials can be tailored to exhibit certain, required properties. At the same time, the fact that these materials are composed of various, sometimes very different constituents, make their mechanical behaviour complex. This observation holds with respect to the deformation behaviour, but especially with respect to the failure behaviour, where complicated and unconventional failure modes have been observed. It is a challenge to develop predictive methods that can capture this complex mechanical behaviour, either using analytical tools, or using numerical me- ods, the ?nite element method being the most widespread among the latter. In this respect, developments have gone fast over the past decade. Indeed, we have seen a paradigm shift in computational approaches to (composite) ma- rial behaviour. Where only a decade ago it was still customary to carry out analyses of deformation and failure at a macroscopic level of observation only – one may call this a phenomenological approach – nowadays this approach is being progressively replaced by multiscale methods. In such methods it is r- ognized a priori that the overall behaviour is highly dependent on local details and ?aws.