Modeling martensitic phase transformation in dual phase steels based on a sharp interface theory
Title | Modeling martensitic phase transformation in dual phase steels based on a sharp interface theory PDF eBook |
Author | Ruck, Johannes |
Publisher | KIT Scientific Publishing |
Pages | 220 |
Release | 2021-05-07 |
Genre | Technology & Engineering |
ISBN | 3731510723 |
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 of Dislocation - Grain Boundary Interactions in Gradient Crystal Plasticity Theories
Title | Modeling of Dislocation - Grain Boundary Interactions in Gradient Crystal Plasticity Theories PDF eBook |
Author | Erdle, Hannes |
Publisher | KIT Scientific Publishing |
Pages | 184 |
Release | 2022-07-12 |
Genre | Technology & Engineering |
ISBN | 3731511967 |
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.
Thermomechanical Modeling and Experimental Characterization of Sheet Molding Compound Composites
Title | Thermomechanical Modeling and Experimental Characterization of Sheet Molding Compound Composites PDF eBook |
Author | Lang, Juliane |
Publisher | KIT Scientific Publishing |
Pages | 250 |
Release | 2023-06-28 |
Genre | |
ISBN | 3731512327 |
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
Title | Microstructure modeling and crystal plasticity parameter identification for predicting the cyclic mechanical behavior of polycrystalline metals PDF eBook |
Author | Kuhn, Jannick |
Publisher | KIT Scientific Publishing |
Pages | 224 |
Release | 2023-04-04 |
Genre | Technology & Engineering |
ISBN | 3731512726 |
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
Title | Microstructure generation and micromechanical modeling of sheet molding compound composites PDF eBook |
Author | Görthofer, Johannes |
Publisher | KIT Scientific Publishing |
Pages | 258 |
Release | 2022-09-13 |
Genre | Technology & Engineering |
ISBN | 373151205X |
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.
Efficient fast Fourier transform-based solvers for computing the thermomechanical behavior of applied materials
Title | Efficient fast Fourier transform-based solvers for computing the thermomechanical behavior of applied materials PDF eBook |
Author | Wicht, Daniel |
Publisher | KIT Scientific Publishing |
Pages | 336 |
Release | 2022-10-11 |
Genre | Science |
ISBN | 3731512203 |
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.
Deep material networks for efficient scale-bridging in thermomechanical simulations of solids
Title | Deep material networks for efficient scale-bridging in thermomechanical simulations of solids PDF eBook |
Author | Gajek, Sebastian |
Publisher | KIT Scientific Publishing |
Pages | 326 |
Release | 2023-08-25 |
Genre | |
ISBN | 3731512785 |
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.