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

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

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

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

Crystal Plasticity Finite Element Methods

Crystal Plasticity Finite Element Methods PDF Author: Franz Roters
Publisher: John Wiley & Sons
ISBN: 3527642099
Category : Technology & Engineering
Languages : en
Pages : 188

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Book Description
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.

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 PDF Author: Kuhn, Jannick
Publisher: KIT Scientific Publishing
ISBN: 3731512726
Category : Technology & Engineering
Languages : en
Pages : 224

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Book Description
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.

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

Single-crystal Gradient Plasticity with an Accumulated Plastic Slip: Theory and Applications PDF Author: Eric Bayerschen
Publisher: KIT Scientific Publishing
ISBN: 3731506068
Category : Technology (General)
Languages : en
Pages : 278

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Book Description
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.

Dislocation Mechanism-Based Crystal Plasticity

Dislocation Mechanism-Based Crystal Plasticity PDF Author: Zhuo Zhuang
Publisher: Academic Press
ISBN: 0128145927
Category : Technology & Engineering
Languages : en
Pages : 452

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Book Description
Dislocation Based Crystal Plasticity: Theory and Computation at Micron and Submicron Scale provides a comprehensive introduction to the continuum and discreteness dislocation mechanism-based theories and computational methods of crystal plasticity at the micron and submicron scale. Sections cover the fundamental concept of conventional crystal plasticity theory at the macro-scale without size effect, strain gradient crystal plasticity theory based on Taylar law dislocation, mechanism at the mesoscale, phase-field theory of crystal plasticity, computation at the submicron scale, including single crystal plasticity theory, and the discrete-continuous model of crystal plasticity with three-dimensional discrete dislocation dynamics coupling finite element method (DDD-FEM). Three kinds of plastic deformation mechanisms for submicron pillars are systematically presented. Further sections discuss dislocation nucleation and starvation at high strain rate and temperature effect for dislocation annihilation mechanism. - Covers dislocation mechanism-based crystal plasticity theory and computation at the micron and submicron scale - Presents crystal plasticity theory without size effect - Deals with the 3D discrete-continuous (3D DCM) theoretic and computational model of crystal plasticity with 3D discrete dislocation dynamics (3D DDD) coupling finite element method (FEM) - Includes discrete dislocation mechanism-based theory and computation at the submicron scale with single arm source, coating micropillar, lower cyclic loading pillars, and dislocation starvation at the submicron scale

Thermomechanical Modeling and Experimental Characterization of Sheet Molding Compound Composites

Thermomechanical Modeling and Experimental Characterization of Sheet Molding Compound Composites PDF Author: Lang, Juliane
Publisher: KIT Scientific Publishing
ISBN: 3731512327
Category :
Languages : en
Pages : 250

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Book Description
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 PDF Author: Görthofer, Johannes
Publisher: KIT Scientific Publishing
ISBN: 373151205X
Category : Technology & Engineering
Languages : en
Pages : 258

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Book Description
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 PDF Author: Holm Altenbach
Publisher: Springer Nature
ISBN: 3030303551
Category : Technology & Engineering
Languages : en
Pages : 530

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Book Description
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.

A computational multi-scale approach for brittle materials

A computational multi-scale approach for brittle materials PDF Author: Ernesti, Felix
Publisher: KIT Scientific Publishing
ISBN: 3731512858
Category : Technology & Engineering
Languages : en
Pages : 264

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Book Description
Materials of industrial interest often show a complex microstructure which directly influences their macroscopic material behavior. For simulations on the component scale, multi-scale methods may exploit this microstructural information. This work is devoted to a multi-scale approach for brittle materials. Based on a homogenization result for free discontinuity problems, we present FFT-based methods to compute the effective crack energy of heterogeneous materials with complex microstructures.

Fiber Orientation Tensors and Mean Field Homogenization: Application to Sheet Molding Compound

Fiber Orientation Tensors and Mean Field Homogenization: Application to Sheet Molding Compound PDF Author: Bauer, Julian Karl
Publisher: KIT Scientific Publishing
ISBN: 3731512629
Category : Technology & Engineering
Languages : en
Pages : 252

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Book Description
Effective mechanical properties of fiber-reinforced composites strongly depend on the microstructure, including the fibers' orientation. Studying this dependency, we identify the variety of fiber orientation tensors up to fourth-order using irreducible tensors and material symmetry. The case of planar fiber orientation tensors, relevant for sheet molding compound, is presented completely. Consequences for the reconstruction of fiber distributions and mean field homogenization are presented.