Computer Simulations of Crystal Plasticity at Different Length Scales PDF Download

Author: Bingqing Cheng
Publisher:
ISBN: 9781361348024
Category :
Languages : en
Pages :

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Author: 程冰清
Publisher:
ISBN:
Category : Crystals
Languages : en
Pages : 0

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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.

Author: Nasr Ghoniem
Publisher: Wiley
ISBN: 9781118410929
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
Multiscale Plasticity Nasr M Ghoniem and Giacomo Po, UCLA, USA A comprehensive treatment of plastic deformation at multiple length scales Plastic deformation is an important subject as a result of the wide use of metals in many technological applications, the fact that it is associated with failure mechanisms, and because of the emergence of strain engineering in the microelectronics industry. Plasticity is also becoming a significant factor in the design of nano and micro systems. Multiscale Plasticity addresses the subject of plasticity in a comprehensive manner, utilizing the multiscale modelling of materials (MMM) approach to systematically reduce the degrees of freedom at natural length scales. At the atomic scale, computer simulation methods, such as Molecular Dynamics (MD) and the Kinetic Monte Carlo (KMC) are presented. The book then discusses the role played by Dislocation Dynamics (DD) and Statistical Mechanics (SM) methods in understanding microstructure self-organization, heterogeneous plastic deformation, material instabilities and failure phenomena. At the macro-scale, emphasis is placed on recent progress made in crystal plasticity, strain gradient elasticity, strain gradient plasticity, and homogenization techniques. Key Features: Presents a physically based approach to the description of plasticity. Modern computational methods are introduced to the reader at multiple length scales, from the atoms all the way up to the continuum level. Direct comparisons between experiment and multiscale modelling. Applications are given in nano and micro-technologies, as well as examples of materials-by-design. Pedagogical in nature, Multiscale Plasticity leads the reader to a more in-depth understanding of plasticity at all length scales for a wide range of applications.

Author: Guruprasad Padubidri Janardhanachar
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The goal of this research work is to further the understanding of crystal plasticity, particularly at reduced structural and material length scales. Fundamental understanding of plasticity is central to various challenges facing design and manufacturing of materials for structural and electronic device applications. The development of microstructurally tailored advanced metallic materials with enhanced mechanical properties that can withstand extremes in stress, strain, and temperature, will aid in increasing the efficiency of power generating systems by allowing them to work at higher temperatures and pressures. High specific strength materials can lead to low fuel consumption in transport vehicles. Experiments have shown that enhanced mechanical properties can be obtained in materials by constraining their size, microstructure (e.g. grain size), or both for various applications. For the successful design of these materials, it is necessary to have a thorough understanding of the influence of different length scales and evolving microstructure on the overall behavior. In this study, distinction is made between the effect of structural and material length scale on the mechanical behavior of materials. A length scale associated with an underlying physical mechanism influencing the mechanical behavior can overlap with either structural length scales or material length scales. If it overlaps with structural length scales, then the material is said to be dimensionally constrained. On the other hand, if it overlaps with material length scales, for example grain size, then the material is said to be microstructurally constrained. The objectives of this research work are: (1) to investigate scale and size effects due to dimensional constraints; (2) to investigate size effects due to microstructural constraints; and (3) to develop a size dependent hardening model through coarse graining of dislocation dynamics. A discrete dislocation dynamics (DDD) framework where the scale of analysis is intermediate between a fully discretized (e.g. atomistic) and fully continuum is used for this study. This mesoscale tool allows to address all the stated objectives of this study within a single framework. Within this framework, the effect of structural and the material length scales are naturally accounted for in the simulations and need not be specified in an ad hoc manner, as in some continuum models. It holds the promise of connecting the evolution of the defect microstructure to the effective response of the crystal. Further, it provides useful information to develop physically motivated continuum models to model size effects in materials. The contributions of this study are: (a) provides a new interpretation of mechanical size effect due to only dimensional constraint using DDD; (b) a development of an experimentally validated DDD simulation methodology to model Cu micropillars; (c) a coarse graining technique using DDD to develop a phenomenological model to capture size effect on strain hardening; and (d) a development of a DDD framework for polycrystals to investigate grain size effect on yield strength and strain hardening.

Author: Dierk Raabe
Publisher: John Wiley & Sons
ISBN: 3527604219
Category : Technology & Engineering
Languages : en
Pages : 885

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Book Description
This book fills a gap by presenting our current knowledge and understanding of continuum-based concepts behind computational methods used for microstructure and process simulation of engineering materials above the atomic scale. The volume provides an excellent overview on the different methods, comparing the different methods in terms of their respective particular weaknesses and advantages. This trains readers to identify appropriate approaches to the new challenges that emerge every day in this exciting domain. Divided into three main parts, the first is a basic overview covering fundamental key methods in the field of continuum scale materials simulation. The second one then goes on to look at applications of these methods to the prediction of microstructures, dealing with explicit simulation examples, while the third part discusses example applications in the field of process simulation. By presenting a spectrum of different computational approaches to materials, the book aims to initiate the development of corresponding virtual laboratories in the industry in which these methods are exploited. As such, it addresses graduates and undergraduates, lecturers, materials scientists and engineers, physicists, biologists, chemists, mathematicians, and mechanical engineers.

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.

Author: Vasily Bulatov
Publisher: Oxford University Press
ISBN: 0198526148
Category : Computers
Languages : en
Pages : 301

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Book Description
The book presents a variety of methods for computer simulations of crystal defects in the form of "numerical recipes", complete with computer codes and analysis tools. By working through numerous case studies and problems, this book provides a useful starter kit for further method development in the computational materials sciences.

Author: Ronald W. Armstrong
Publisher: MDPI
ISBN: 3036508740
Category : Science
Languages : en
Pages : 322

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Book Description
The present collection of articles focuses on the mechanical strength properties at micro- and nanoscale dimensions of body-centered cubic, face-centered cubic and hexagonal close-packed crystal structures. The advent of micro-pillar test specimens is shown to provide a new dimensional scale for the investigation of crystal deformation properties. The ultra-small dimensional scale at which these properties are measured is shown to approach the atomic-scale level at which model dislocation mechanics descriptions of crystal slip and deformation twinning behaviors are proposed to be operative, including the achievement of atomic force microscopic measurements of dislocation pile-up interactions with crystal grain boundaries or with hard surface coatings. A special advantage of engineering designs made at such small crystal and polycrystalline dimensions is the achievement of an approximate order-of-magnitude increase in mechanical strength levels. Reasonable extrapolation of macro-scale continuum mechanics descriptions of crystal strength properties at micro- to nano-indentation hardness measurements are demonstrated, in addition to reports on persistent slip band observations and fatigue cracking behaviors. High-entropy alloy, superalloy and energetic crystal properties are reported along with descriptions of deformation rate sensitivities, grain boundary structures, nano-cutting, void nucleation/growth micromechanics and micro-composite electrical properties.

Author: Jörg Schröder
Publisher: Springer Science & Business Media
ISBN: 3709116252
Category : Science
Languages : en
Pages : 417

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Book Description
The book presents the latest findings in experimental plasticity, crystal plasticity, phase transitions, advanced mathematical modeling of finite plasticity and multi-scale modeling. The associated algorithmic treatment is mainly based on finite element formulations for standard (local approach) as well as for non-standard (non-local approach) continua and for pure macroscopic as well as for directly coupled two-scale boundary value problems. Applications in the area of material design/processing are covered, ranging from grain boundary effects in polycrystals and phase transitions to deep-drawing of multiphase steels by directly taking into account random microstructures.