Advances in Extended and Multifield Theories for Continua PDF Download

Author: Bernd Markert
Publisher: Springer Science & Business Media
ISBN: 3642227384
Category : Science
Languages : en
Pages : 231

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Book Description
Modern computational techniques, such as the Finite Element Method, have, since their development several decades ago, successfully exploited continuum theories for numerous applications in science and technology. Although standard continuum methods based upon the Cauchy-Boltzmann continuum are still of great importance and are widely used, it increasingly appears that material properties stemming from microstructural phenomena have to be considered. This is particularly true for inhomogeneous load and deformation states, where lower-scale size effects begin to affect the macroscopic material response; something standard continuum theories fail to account for. Following this idea, it is evident that standard continuum mechanics has to be augmented to capture lower-scale structural and compositional phenomena, and to make this information accessible to macroscopic numerical simulations.

Author: Gianfranco Capriz
Publisher: Springer Science & Business Media
ISBN: 0817681582
Category : Mathematics
Languages : en
Pages : 269

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Book Description
Toachieve design, implementation,and servicing ofcomplex systems and struc tures in an efficient and cost-effective way,a deeper knowledge and understanding of the subtle cast and detailed evolution of materials is needed. The analysis in demand borders with the molecular and atomic one, spanning all the way down from classical continua. The study of the behavior of complex materials in sophisticated devices also opens intricate questions about the applicability of primary axioms ofcontinuum mechanics such as the ultimate nature of the material element itselfand the possibility ofidentifying itperfectly. So it is necessary to develop tools that allow usto formulate both theoretical models and methods of numerical approximation for the analysis of material substructures. Multifield theories in continuum mechanics, which bridge classical materials science and modern continuum mechanics, provide precisely these tools. Multifield theories not only address problems of material substructures, but also encompass well-recognized approaches to the study of soft condensed matter and allow one to model disparate conditions in various states ofmatter. However, research inmultifield theories is vast, and there is little in the way of a comprehensive distillation of the subject from an engineer's perspective. Therefore, the papers in the present volume, 1 which grew out of our experience as editors for an engineeringjournal, tackle some fundamental questions,suggest solutions of concrete problems, and strive to interpret a host of experimental evidence. In this spirit, each of the authors has contributed original results having in mind their wider applicability.

Author: Prahs, Andreas
Publisher: KIT Scientific Publishing
ISBN: 3731510251
Category : Technology & Engineering
Languages : en
Pages : 182

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Book Description
An overview of different methods for the derivation of extended continuum models is given. A gradient plasticity theory is established in the context of small deformations and single slip by considering the invariance of an extended energy balance with respect to Euclidean transformations, where the plastic slip is considered as an additional degree of freedom. Thermodynamically consistent flow rules at the grain boundary are derived. The theory is applied to a two- and a three-phase laminate.

Author: Victor A. Eremeyev
Publisher: Springer Science & Business Media
ISBN: 3642283535
Category : Science
Languages : en
Pages : 145

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Book Description
The book presents foundations of the micropolar continuum mechanics including a short but comprehensive introduction of stress and strain measures, derivation of motion equations and discussion of the difference between Cosserat and classical (Cauchy) continua, and the discussion of more specific problems related to the constitutive modeling, i.e. constitutive inequalities, symmetry groups, acceleration waves, etc.

Author: Erdle, Hannes
Publisher: KIT Scientific Publishing
ISBN: 3731511967
Category : Technology & Engineering
Languages : en
Pages : 184

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Book Description
A physically-based dislocation theory of plasticity is derived within an extended continuum mechanical context. Thermodynamically consistent flow rules at the grain boundaries are derived. With an analytical solution of a three-phase periodic laminate, dislocation pile-up at grain boundaries and dislocation transmission through the grain boundaries are investigated. For the finite element implementations, numerically efficient approaches are introduced based on accumulated field variables.

Author: Holm Altenbach
Publisher: Springer Nature
ISBN: 3031043545
Category : Technology & Engineering
Languages : en
Pages : 289

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Book Description
The book introduces advanced theories for deformation, damage, and failure in materials. The overall continuum mechanical framework was marked out and added by creep and damage mechanics of materials at elevated temperatures. The time-dependent and time-independent models of cyclic plasticity for low cycle and thermomechanical fatigue life assessment were specified in a very special manner: instead of three-dimensional statements, only one-dimensional rheological models were discussed. Anisotropic plasticity during non-proportional loading and anisotropy of yield/failure criteria is more and more important in modern applications. It is showing how the limit states of materials can be estimated. In addition, the damage and failure of composite materials demonstrate the possibility to extend continuum mechanics to continuum damage mechanics of composite materials.

Author: Holm Altenbach
Publisher: Springer Science & Business Media
ISBN: 3709113709
Category : Technology & Engineering
Languages : en
Pages : 403

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Book Description
On the roots of continuum mechanics in differential geometry -- a review.- Cosserat media.- Cosserat-type shells.- Cosserat-type rods.- Micromorphic media.- Electromagnetism and generalized continua.- Computational methods for generalized continua. The need of generalized continua models is coming from practice. Complex material behavior sometimes cannot be presented by the classical Cauchy continua. At present the attention of the scientists in this field is focused on the most recent research items • new models, • application of well-known models to new problems, • micro-macro aspects, • computational effort, and • possibilities to identify the constitutive equations The new research directions are discussed in this volume - from the point of view of modeling and simulation, identification, and numerical methods.

Author: Jan Knippers
Publisher: Springer
ISBN: 3319463748
Category : Science
Languages : en
Pages : 408

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Book Description
This book comprises a first survey of the Collaborative Research Center SFB-TRR 141 ‘Biological Design and Integrative Structures – Analysis, Simulation and Implementation in Architecture’, funded by the Deutsche Forschungsgemeinschaft since October 2014. The SFB-TRR 141 provides a collaborative framework for architects and engineers from the University of Stuttgart, biologists and physicists from the University of Freiburg and geoscientists and evolutionary biologists from the University of Tübingen. The programm is conceptualized as a dialogue between the disciplines and is based on the belief that that biomimetic research has the potential to lead everyone involved to new findings far beyond his individual reach. During the last few decades, computational methods have been introduced into all fields of science and technology. In architecture, they enable the geometric differentiation of building components and allow the fabrication of porous or fibre-based materials with locally adjusted physical and chemical properties. Recent developments in simulation technologies focus on multi-scale models and the interplay of mechanical phenomena at various hierarchical levels. In the natural sciences, a multitude of quantitative methods covering diverse hierarchical levels have been introduced. These advances in computational methods have opened a new era in biomimetics: local differentiation at various scales, the main feature of natural constructions, can for the first time not only be analysed, but to a certain extent also be transferred to building construction. Computational methodologies enable the direct exchange of information between fields of science that, until now, have been widely separated. As a result they lead to a new approach to biomimetic research, which, hopefully, contributes to a more sustainable development in architecture and building construction.

Author: Tobias Gleim
Publisher: kassel university press GmbH
ISBN: 3737650934
Category : Technology & Engineering
Languages : en
Pages : 493

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Book Description
This conference book contains papers presented at the 8th GACM Colloquium on Computational Mechanics for Young Scientists from Academia and Industry. The conference was held from August 28th – 30th, 2019 in Kassel, hosted by the Institute of Mechanics and Dynamics of the department for civil and environmental engineering and by the chair of Engineering Mechanics / Continuum Mechanics of the department for mechanical engineering of the University of Kassel. The aim of the conference is, to bring together young scientits who are engaged in academic and industrial research on Computational Mechanics and Computer Methods in Applied Sciences. It provides a plattform to present and discuss recent results from research efforts and industrial applications. In more than 150 presentations, given by young scientists, current scientific developments and advances in engineering practice in this field are presented and discussed. The contributions of the young researchers are supplemented by a poster session and plenary talks from four senior scientists from academia and industry as well as from the GACM Best PhD Award winners 2017 and 2018.

Author: Tarek I. Zohdi
Publisher: Springer Science & Business Media
ISBN: 3642284272
Category : Technology & Engineering
Languages : en
Pages : 188

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Book Description
Recently, several applications, primarily driven by microtechnology, have emerged where the use of materials with tailored electromagnetic (dielectric) properties are necessary for a successful overall design. The ``tailored'' aggregate properties are achieved by combining an easily moldable base matrix with particles having dielectric properties that are chosen to deliver (desired) effective properties. In many cases, the analysis of such materials requires the simulation of the macroscopic and microscopic electromagnetic response, as well as its resulting coupled thermal response, which can be important to determine possible failures in ``hot spots.'' This necessitates a stress analysis. Furthermore, because, oftentimes, such processes initiate degratory chemical processes, it can be necessary to also include models for these processes as well. A central objective of this work is to provide basic models and numerical solution strategies to analyze the coupled response of such materials by direct simulation using standard laptop/desktop equipment. Accordingly, this monograph covers: (1) The foundations of Maxwell's equations, (2) Basic homogenization theory, (3) Coupled systems (electromagnetic, thermal, mechanical and chemical), (4) Numerical methods and (5) An introduction to select biological problems. The text can be viewed as a research monograph suitable for use in an upper-division undergraduate or first year graduate course geared towards students in the applied sciences, mechanics and mathematics that have an interest in the analysis of particulate materials.