Homogenization of the Linear and Non-linear Mechanical Behavior of Polycrystals

Homogenization of the Linear and Non-linear Mechanical Behavior of Polycrystals PDF

Author: Katja Jöchen

Publisher: KIT Scientific Publishing

Published: 2014-05-13

Total Pages: 216

ISBN-13: 3866449712

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This work is dedicated to the numerically efficient simulation of the material response of polycrystalline aggregates. Therefore, crystal plasticity is combined with a new non-linear homogenization scheme, which is based on piecewise constant stress polarizations with respect to a homogeneous reference medium and corresponds to a generalization of the Hashin-Shtrikman scheme. This mean field approach accounts for the one- and two-point statistics of the microstructure.

Homogenization of the Linear and Non-linear Mechanical Behavior of Polycrystals

Homogenization of the Linear and Non-linear Mechanical Behavior of Polycrystals PDF

Author:

Publisher:

Published: 2013

Total Pages: 0

ISBN-13: 9781000032284

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This work is dedicated to the numerically efficient simulation of the material response of polycrystalline aggregates. Therefore, crystal plasticity is combined with a new non-linear homogenization scheme, which is based on piecewise constant stress polarizations with respect to a homogeneous reference medium and corresponds to a generalization of the Hashin-Shtrikman scheme. This mean field approach accounts for the one- and two-point statistics of the microstructure.

Nonlinear Homogenization and its Applications to Composites, Polycrystals and Smart Materials

Nonlinear Homogenization and its Applications to Composites, Polycrystals and Smart Materials PDF

Author: P. Ponte Castaneda

Publisher: Springer Science & Business Media

Published: 2006-02-17

Total Pages: 371

ISBN-13: 1402026234

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Although several books and conference proceedings have already appeared dealing with either the mathematical aspects or applications of homogenization theory, there seems to be no comprehensive volume dealing with both aspects. The present volume is meant to fill this gap, at least partially, and deals with recent developments in nonlinear homogenization emphasizing applications of current interest. It contains thirteen key lectures presented at the NATO Advanced Workshop on Nonlinear Homogenization and Its Applications to Composites, Polycrystals and Smart Materials. The list of thirty one contributed papers is also appended. The key lectures cover both fundamental, mathematical aspects of homogenization, including nonconvex and stochastic problems, as well as several applications in micromechanics, thin films, smart materials, and structural and topology optimization. One lecture deals with a topic important for nanomaterials: the passage from discrete to continuum problems by using nonlinear homogenization methods. Some papers reveal the role of parameterized or Young measures in description of microstructures and in optimal design. Other papers deal with recently developed methods – both analytical and computational – for estimating the effective behavior and field fluctuations in composites and polycrystals with nonlinear constitutive behavior. All in all, the volume offers a cross-section of current activity in nonlinear homogenization including a broad range of physical and engineering applications. The careful reader will be able to identify challenging open problems in this still evolving field. For instance, there is the need to improve bounding techniques for nonconvex problems, as well as for solving geometrically nonlinear optimum shape-design problems, using relaxation and homogenization methods.

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

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.

Micromechanical Modeling and Simulation of Forming Processes

Micromechanical Modeling and Simulation of Forming Processes PDF

Author: Glavas, Vedran

Publisher: KIT Scientific Publishing

Published: 2016-12-21

Total Pages: 158

ISBN-13: 3731506025

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The deep drawing of an aluminum alloy used in the packaging industry for the beverage can manufacturing process is investigated. In this work, the effective constitutive behavior is based on a crystal plasticity model in combination with a non-linear Hashin-Shtrikman type homogenization scheme in which a reference stiffness controls the stress and strain fluctuations. The simulation results are compared to experiments in terms of deep drawing earing profiles, texture evolution, and localization.

Finite element simulation of dislocation based plasticity and diffusion in multiphase materials at high temperature

Finite element simulation of dislocation based plasticity and diffusion in multiphase materials at high temperature PDF

Author: Albiez, Jürgen

Publisher: KIT Scientific Publishing

Published: 2019-05-22

Total Pages: 222

ISBN-13: 3731509180

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A single-crystal plasticity model as well as a gradient crystal plasticity model are used to describe the creep behavior of directionally solidi?ed NiAl based eutectic alloys. To consider the transition from theoretical to bulk strength, a hardening model was introduced to describe the strength of the reinforcing phases. Moreover, to account for microstructural changes due to material ?ux, a coupled diffusional-mechanical simulation model was introduced.

A Gradient Crystal Plasticity Theory Based on an Extended Energy Balance

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

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.

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

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.