Modeling of Dislocation - Grain Boundary Interactions in Gradient Crystal Plasticity Theories
Modeling of Dislocation - Grain Boundary Interactions in Gradient Crystal Plasticity Theories

Author: Erdle, Hannes

Publisher: KIT Scientific Publishing

Published: 2022-07-12

Total Pages: 184

ISBN-13: 3731511967

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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.

Crystal Plasticity Finite Element Methods
Crystal Plasticity Finite Element Methods

Author: Franz Roters

Publisher: John Wiley & Sons

Published: 2011-08-04

Total Pages: 188

ISBN-13: 3527642099

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Written by the leading experts in computational materials science, this handy reference concisely reviews the most important aspects of plasticity modeling: constitutive laws, phase transformations, texture methods, continuum approaches and damage mechanisms. As a result, it provides the knowledge needed to avoid failures in critical systems udner mechanical load. With its various application examples to micro- and macrostructure mechanics, this is an invaluable resource for mechanical engineers as well as for researchers wanting to improve on this method and extend its outreach.

Single-crystal Gradient Plasticity with an Accumulated Plastic Slip: Theory and Applications
Single-crystal Gradient Plasticity with an Accumulated Plastic Slip: Theory and Applications

Author: Eric Bayerschen

Publisher: KIT Scientific Publishing

Published: 2016

Total Pages: 278

ISBN-13: 3731506068

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In experiments on metallic microwires, size effects occur as a result of the interaction of dislocations with, e.g., grain boundaries. In continuum theories this behavior can be approximated using gradient plasticity. A numerically efficient geometrically linear gradient plasticity theory is developed considering the grain boundaries and implemented with finite elements. Simulations are performed for several metals in comparison to experiments and discrete dislocation dynamics simulations.

A Gradient Crystal Plasticity Theory Based on an Extended Energy Balance
A Gradient Crystal Plasticity Theory Based on an Extended Energy Balance

Author: Prahs, Andreas

Publisher: KIT Scientific Publishing

Published: 2020-09-15

Total Pages: 182

ISBN-13: 3731510251

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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.

Microstructure modeling and crystal plasticity parameter identification for predicting the cyclic mechanical behavior of polycrystalline metals
Microstructure modeling and crystal plasticity parameter identification for predicting the cyclic mechanical behavior of polycrystalline metals

Author: Kuhn, Jannick

Publisher: KIT Scientific Publishing

Published: 2023-04-04

Total Pages: 224

ISBN-13: 3731512726

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Computational homogenization permits to capture the influence of the microstructure on the cyclic mechanical behavior of polycrystalline metals. In this work we investigate methods to compute Laguerre tessellations as computational cells of polycrystalline microstructures, propose a new method to assign crystallographic orientations to the Laguerre cells and use Bayesian optimization to find suitable parameters for the underlying micromechanical model from macroscopic experiments.

Numerically Efficient Gradient Crystal Plasticity With a Grain Boundary Yield Criterion and Dislocation-based Work-Hardening
Numerically Efficient Gradient Crystal Plasticity With a Grain Boundary Yield Criterion and Dislocation-based Work-Hardening

Author: Stephan Wulfinghoff

Publisher:

Published: 2020-10-09

Total Pages: 282

ISBN-13: 9781013280351

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This book is a contribution to the further development of gradient plasticity. Several open questions are addressed, where the efficient numerical implementation is particularly focused on. Thebook inspects an equivalent plastic strain gradient plasticity theory and a grain boundary yield model. Experiments can successfully be reproduced. The hardening model is based on dislocation densities evolving according to partial differential equations taking into account dislocation transport. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.

Thermomechanical Modeling and Experimental Characterization of Sheet Molding Compound Composites
Thermomechanical Modeling and Experimental Characterization of Sheet Molding Compound Composites

Author: Lang, Juliane

Publisher: KIT Scientific Publishing

Published: 2023-06-28

Total Pages: 250

ISBN-13: 3731512327

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The aim of this work is to model and experimentally characterize the anisotropic material behavior of SMC composites on the macroscale with consideration of the microstructure. Temperature-dependent thermoelastic behavior and failure behavior are modeled and the corresponding material properties are determined experimentally. Additionally, experimental biaxial damage investigations are performed. A parameter identification merges modeling and experiments and validates the models.

Microstructure generation and micromechanical modeling of sheet molding compound composites
Microstructure generation and micromechanical modeling of sheet molding compound composites

Author: Görthofer, Johannes

Publisher: KIT Scientific Publishing

Published: 2022-09-13

Total Pages: 258

ISBN-13: 373151205X

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Wir präsentieren einen Algorithmus zur schnellen Erzeugung von SMC Mikrostrukturen hoher Güte, durch Verwendung einer exakten Schließung und eines quasi-zufälligen Samplings. Darüber hinaus stellen wir ein modulares Framework zur Modellierung anisotroper Schädigung vor. Unser Konzept der Extraktionstensoren und Schädigungsfunktionen ermöglicht die Beschreibung komplexer Vorgänge. Darüber hinaus schlagen wir einen ganzheitlichen Multiskalenansatz zur Bestimmung anisotroper Versagenskriterien vor. - We introduce an algorithm that allows for a fast generation of SMC composite microstructures. An exact closure approximation and a quasi-random orientation sampling ensure high fidelity. Furthermore, we present a modular framework for anisotropic damage evolution. Our concept of extraction tensors and damage-hardening functions enables the description of complex damage-degradation. In addition, we propose a holistic multiscale approach for constructing anisotropic failure criteria.

State of the Art and Future Trends in Material Modeling
State of the Art and Future Trends in Material Modeling

Author: Holm Altenbach

Publisher: Springer Nature

Published: 2019-10-23

Total Pages: 505

ISBN-13: 3030303551

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This special anniversary book celebrates the success of this Springer book series highlighting materials modeling as the key to developing new engineering products and applications. In this 100th volume of “Advanced Structured Materials”, international experts showcase the current state of the art and future trends in materials modeling, which is essential in order to fulfill the demanding requirements of next-generation engineering tasks.

Deep material networks for efficient scale-bridging in thermomechanical simulations of solids
Deep material networks for efficient scale-bridging in thermomechanical simulations of solids

Author: Gajek, Sebastian

Publisher: KIT Scientific Publishing

Published: 2023-08-25

Total Pages: 326

ISBN-13: 3731512785

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We investigate deep material networks (DMN). We lay the mathematical foundation of DMNs and present a novel DMN formulation, which is characterized by a reduced number of degrees of freedom. We present a efficient solution technique for nonlinear DMNs to accelerate complex two-scale simulations with minimal computational effort. A new interpolation technique is presented enabling the consideration of fluctuating microstructure characteristics in macroscopic simulations.