Modeling martensitic phase transformation in dual phase steels based on a sharp interface theory

Modeling martensitic phase transformation in dual phase steels based on a sharp interface theory PDF Author: Ruck, Johannes
Publisher: KIT Scientific Publishing
ISBN: 3731510723
Category : Technology & Engineering
Languages : en
Pages : 220

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Book Description
artensite forms under rapid cooling of austenitic grains accompanied by a change of the crystal lattice. Large deformations are induced which lead to plastic dislocations. In this work a transformation model based on the sharp interface theory, set in a finite strain context is developed. Crystal plasticity effects, the kinetic of the singular surface as well as a simple model of the inheritance from austenite dislocations into martensite are accounted for.

Modeling martensitic phase transformation in dual phase steels based on a sharp interface theory

Modeling martensitic phase transformation in dual phase steels based on a sharp interface theory PDF Author: Ruck, Johannes
Publisher: KIT Scientific Publishing
ISBN: 3731510723
Category : Technology & Engineering
Languages : en
Pages : 220

Get Book Here

Book Description
artensite forms under rapid cooling of austenitic grains accompanied by a change of the crystal lattice. Large deformations are induced which lead to plastic dislocations. In this work a transformation model based on the sharp interface theory, set in a finite strain context is developed. Crystal plasticity effects, the kinetic of the singular surface as well as a simple model of the inheritance from austenite dislocations into martensite are accounted for.

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 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.

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.

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.

Efficient fast Fourier transform-based solvers for computing the thermomechanical behavior of applied materials

Efficient fast Fourier transform-based solvers for computing the thermomechanical behavior of applied materials PDF Author: Wicht, Daniel
Publisher: KIT Scientific Publishing
ISBN: 3731512203
Category : Science
Languages : en
Pages : 336

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Book Description
The mechanical behavior of many applied materials arises from their microstructure. Thus, to aid the design, development and industrialization of new materials, robust computational homogenization methods are indispensable. The present thesis is devoted to investigating and developing FFT-based micromechanics solvers for efficiently computing the (thermo)mechanical response of nonlinear composite materials with complex microstructures.

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.

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

Deep material networks for efficient scale-bridging in thermomechanical simulations of solids PDF Author: Gajek, Sebastian
Publisher: KIT Scientific Publishing
ISBN: 3731512785
Category :
Languages : en
Pages : 326

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Book Description
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.

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.

Martensitic Transformation

Martensitic Transformation PDF Author: Zenji Nishiyama
Publisher: Elsevier
ISBN: 0323148816
Category : Technology & Engineering
Languages : en
Pages : 480

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Book Description
Martensitic Transformation examines martensitic transformation based on the known crystallographical data. Topics covered range from the crystallography of martensite to the transformation temperature and rate of martensite formation. The conditions for martensite formation and stabilization of austenite are also discussed, along with the crystallographic theory of martensitic transformations. Comprised of six chapters, this book begins with an introduction to martensite and martensitic transformation, with emphasis on the basic properties of martensite in steels such as carbon steels. The next two chapters deal with the crystallography of martensite and discuss the martensitic transformation behavior of the second-order transition; lattice imperfections in martensite; and close-packed layer structures of martensites produced from ? phase in noble-metal-base alloys. Thermodynamical problems and kinetics are also analysed, together with conditions for the nucleation of martensite and problems concerning stabilization of austenite. The last chapter discusses the theory of the mechanism underlying martensitic transformation. This monograph will be of interest to metallurgists and materials scientists.