Author: Sophie Lemaitre
Publisher:
ISBN:
Category :
Languages : fr
Pages : 155
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Book Description
Ce mémoire aborde les questions relatives à la mise en place de procédures de conception rapide, fiable et automatisée des volumes élémentaires représentatifs (VER) d'un matériau composite à microstructure complexe (matrice/inclusions), et de la détermination de leurs propriétés homogénéisées ou effectives. Nous avons conçu et développé des algorithmes conduisant à des outils efficaces permettant la génération aléatoire de tels matériaux à inclusions sphériques, cylindriques, elliptiques ou toute combinaison de celles-ci. Ces outils sont également capables d'altérer les inclusions : inflation, déflation, arrachements aléatoires, ondulation et de les pelliculer permettant ainsi de générer des VER s'approchant des matériaux composites fabriqués. Un soin particulier a été porté sur la génération de VER périodiques. Les caractéristiques homogénéisées ou propriétés effectives de matériaux constitués de tels VER périodiques peuvent alors être déterminées selon le principe d'homogénéisation périodique, soit par une méthode basée sur un schéma itératif utilisant la FFT (Transformation de Fourier Rapide) via l'équation de Lippmann-Schwinger, soit par une méthode d'éléments finis. Le caractère aléatoire de la génération nous amène à réaliser des études en moyenne à partir d'un ensemble de paramètres morphologiques déterminé : nombre d'inclusions, type et forme, fraction volumique, orientation des inclusions, prise en compte d'une éventuelle altération. Deux études particulières sur la conductivité thermique apparente ont été menées, la première sur les composites à inclusions sphériques pelliculées de façon à déterminer l'influence de l'épaisseur de la pellicule et la seconde sur les composites de type stratifié en polymère et fibre de carbone, cousu par un fil de cuivre pour évaluer l'apport de la couture en cuivre selon la fibre de carbone utilisée.
Author: Stefan Diebels
Publisher: Springer
ISBN: 366257957X
Category : Science
Languages : en
Pages : 183
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Book Description
Due to their high stiffness and strength and their good processing properties short fibre reinforced thermoplastics are well-established construction materials. Up to now, simulation of engineering parts consisting of short fibre reinforced thermoplastics has often been based on macroscopic phenomenological models, but deformations, damage and failure of composite materials strongly depend on their microstructure. The typical modes of failure of short fibre thermoplastics enriched with glass fibres are matrix failure, rupture of fibres and delamination, and pure macroscopic consideration is not sufficient to predict those effects. The typical predictive phenomenological models are complex and only available for very special failures. A quantitative prediction on how failure will change depending on the content and orientation of the fibres is generally not possible, and the direct involvement of the above effects in a numerical simulation requires multi-scale modelling. One the one hand, this makes it possible to take into account the properties of the matrix material and the fibre material, the microstructure of the composite in terms of fibre content, fibre orientation and shape as well as the properties of the interface between fibres and matrix. On the other hand, the multi-scale approach links these local properties to the global behaviour and forms the basis for the dimensioning and design of engineering components. Furthermore, multi-scale numerical simulations are required to allow efficient solution of the models when investigating three-dimensional problems of dimensioning engineering parts. Bringing together mathematical modelling, materials mechanics, numerical methods and experimental engineering, this book provides a unique overview of multi-scale modelling approaches, multi-scale simulations and experimental investigations of short fibre reinforced thermoplastics. The first chapters focus on two principal subjects: the mathematical and mechanical models governing composite properties and damage description. The subsequent chapters present numerical algorithms based on the Finite Element Method and the Boundary Element Method, both of which make explicit use of the composite’s microstructure. Further, the results of the numerical simulations are shown and compared to experimental results. Lastly, the book investigates deformation and failure of composite materials experimentally, explaining the applied methods and presenting the results for different volume fractions of fibres. This book is a valuable resource for applied mathematics, theoretical and experimental mechanical engineers as well as engineers in industry dealing with modelling and simulation of short fibre reinforced composites.
Author: George Chatzigeorgiou
Publisher: Elsevier
ISBN: 0128233702
Category : Technology & Engineering
Languages : en
Pages : 366
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Book Description
Multiscale Modeling Approaches for Composites outlines the fundamentals of common multiscale modeling techniques and provides detailed guidance for putting them into practice. Various homogenization methods are presented in a simple, didactic manner, with an array of numerical examples. The book starts by covering the theoretical underpinnings of tensors and continuum mechanics concepts, then passes to actual micromechanic techniques for composite media and laminate plates. In the last chapters the book covers advanced topics in homogenization, including Green's tensor, Hashin-Shtrikman bounds, and special types of problems. All chapters feature comprehensive analytical and numerical examples (Python and ABAQUS scripts) to better illustrate the theory. - Bridges theory and practice, providing step-by-step instructions for implementing multiscale modeling approaches for composites and the theoretical concepts behind them - Covers boundary conditions, data-exchange between scales, the Hill-Mandel principle, average stress and strain theorems, and more - Discusses how to obtain composite properties using different boundary conditions - Includes access to a companion site, featuring the numerical examples, Python and ABACUS codes discussed in the book
Author: Young W. Kwon
Publisher: Springer Science & Business Media
ISBN: 0387685561
Category : Science
Languages : en
Pages : 634
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Book Description
This book presents the state-of-the-art in multiscale modeling and simulation techniques for composite materials and structures. It focuses on the structural and functional properties of engineering composites and the sustainable high performance of components and structures. The multiscale techniques can be also applied to nanocomposites which are important application areas in nanotechnology. There are few books available on this topic.
Author: Vladimir Kompiš
Publisher: Springer
ISBN: 9781402069741
Category : Technology & Engineering
Languages : en
Pages : 302
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Book Description
This book presents new results in the knowledge and simulations for composite nano-materials. It includes selected, extended papers presented in the thematic ECCOMAS conference on Composites with Micro- and Nano-Structure (CMNS) – Computational Modelling and Experiments. It contains atomistic and continuum numerical methods and experimental validation for composite materials reinforced with particles or fibres, porous materials, homogenization and other important topics.
Author: Andrej V. Cherkaev
Publisher: Springer
ISBN: 3319971840
Category : Mathematics
Languages : en
Pages : 327
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Book Description
Over the past several decades, we have witnessed a renaissance of theoretical work on the macroscopic behavior of microscopically heterogeneous materials. This activity brings together a number of related themes, including: (1) the use of weak convergence as a rigorous yet general language for the discussion of macroscopic behavior; (2) interest in new types of questions, particularly the "G-closure problem," motivated in large part by applications of optimal control theory to structural optimization; (3) the introduction of new methods for bounding effective moduli, including one based on "compensated compactness"; and (4) the identification of deep links between the analysis of microstructures and the multidimensional calculus of variations. This work has implications for many physical problems involving optimal design, composite materials, and coherent phase transitions. As a result, it has received attention and support from numerous scientific communities, including engineering, materials science, and physics, as well as mathematics. There is by now an extensive literature in this area. But for various reasons certain fundamental papers were never properly published, circulating instead as mimeographed notes or preprints. Other work appeared in poorly distributed conference proceedings volumes. Still other work was published in standard books or journals, but written in Russian or French. The net effect is a sort of "gap" in the literature, which has made the subject unnecessarily difficult for newcomers to penetrate. The present, softcover reprint is designed to make this classic text available to a wider audience. "Summarizes some of the fundamental results achieved and offers new perspectives in the mechanics of composite and micromechanics... Will become a classic in the two fields." —Applied Mechanics Review
Author: Michael N. Fardis
Publisher: Springer Science & Business Media
ISBN: 9400719779
Category : Technology & Engineering
Languages : en
Pages : 392
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Book Description
Nowadays research in earthquake engineering is mainly experimental and in large-scale; advanced computations are integrated with large-scale experiments, to complement them and extend their scope, even by coupling two different but simultaneous tests. Earthquake engineering cannot give answers by testing and qualifying few, small typical components or single large prototypes. Besides, the large diversity of Civil Engineering structures does not allow drawing conclusions from only a few tests; structures are large and their seismic response and performance cannot be meaningfully tested in an ordinary lab or in the field. So, seismic testing facilities should be much larger than in other scientific fields; their staff has to be resourceful, devising intelligent ways to carry out simultaneously different tests and advanced computations. To better serve such a mission European testing facilities and researchers in earthquake engineering have shared their resources and activities in the framework of the European project SERIES, combining their research and jointly developing advanced testing and instrumentation techniques that maximize testing capabilities and increase the value of the tests. This volume presents the first outcomes of the SERIES and its contribution towards Performance-based Earthquake Engineering, i.e., to the most important development in Earthquake Engineering of the past three decades. The concept and the methodologies for performance-based earthquake engineering have now matured. However, they are based mainly on analytical/numerical research; large-scale seismic testing has entered the stage recently. The SERIES Workshop in Ohrid (MK) in Sept. 2010 pooled together the largest European seismic testing facilities, Europe’s best experts in experimental earthquake engineering and select experts from the USA, to present recent research achievements and to address future developments. Audience: This volume will be of interest to researchers and advanced practitioners in structural earthquake engineering, geotechnical earthquake engineering, engineering seismology, and experimental dynamics, including seismic qualification.
Author: Z. P. Bažant
Publisher: Spon Press
ISBN: 9780419186304
Category : Technology & Engineering
Languages : en
Pages : 934
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Book Description
Presents the proceedings of the 5th RILEM International Symposium, held in Barcelona in September 1993. The papers discuss creep and shrinkage of concrete, and should be of interest to cement and concrete technologists and researchers, as well as structural engineers.
Author: Mohamed Thariq Hameed Sultan
Publisher: Springer Nature
ISBN: 9813340916
Category : Technology & Engineering
Languages : en
Pages : 345
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Book Description
The book highlights the recent research developments in biocomposite design, mechanical performance and utility. It discusses innovative experimental approaches along with mechanical designs and manufacturing aspects of various fibrous polymer matrix composites and presents examples of the synthesis and development of biocomposites and their applications. It is useful for researchers developing biocomposite materials for biomedical and environmental applications.
Author: Patrick De Buhan
Publisher: Elsevier
ISBN: 0081021135
Category : Technology & Engineering
Languages : en
Pages : 344
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Book Description
Elastic, Plastic and Yield Design of Reinforced Structures presents a whole set of new results which have been published by the authors over the last 30 years in the field of continuum solid mechanics applied to the analysis and design of reinforced civil engineering structures. The focus is on the development and application of up-scaling/homogenization methods in the design of such composite structures, with a special emphasis on the plastic behavior and ultimate strength of materials. The specificity of the book is highlighted by at least two completely innovative concepts which lie at the very heart of the book's originality: the elaboration of a fully comprehensive homogenization-based method for the design of reinforced structures (and not only materials), through the study of macroscopic behavior, and the development of a multiphase model for materials reinforced by linear inclusions, which considerably extends the range of applicability of the classical homogenization procedure. - Sums up almost thirty years of original research in the field of mechanics applied to the analysis and design of reinforced civil engineering structures - Focuses on the application of upscaling/homogenization methods to the design of civil engineering structures - Highlights the elaboration of a fully comprehensive homogenization-based method for the design of reinforced structures (and not only materials), through the concept of macroscopic behavior - Features development of a multiphase model for materials reinforced by linear inclusions, which considerably extends the range of applicability of the classical homogenization procedure.
