Biaxial Characterization and Mean-field Based Damage Modeling of Sheet Molding Compound Composites

Biaxial Characterization and Mean-field Based Damage Modeling of Sheet Molding Compound Composites
Author: Schemmann, Malte
Publisher: KIT Scientific Publishing
Total Pages: 194
Release: 2018-11-09
Genre: Automobile industry and trade
ISBN: 3731508184

The focus of this work lies on the microstructure-based modeling and characterization of a discontinuous fiber-reinforced thermoset in the form of sheet molding compound (SMC). A microstructure-based parameter identification scheme for SMC with an inhomogeneous fiber orientation distribution is introduced. Different cruciform specimen designs, including two concepts to reinforce the specimens' arms are evaluated. Additionally, a micromechanical mean-field damage model for the SMC is introduced.

Biaxial Characterization and Mean-field Based Damage Modeling of Sheet Molding Compound Composites

Biaxial Characterization and Mean-field Based Damage Modeling of Sheet Molding Compound Composites
Author: Malte Schemmann
Publisher:
Total Pages: 186
Release: 2020-10-09
Genre: Technology & Engineering
ISBN: 9781013278693

The focus of this work lies on the microstructure-based modeling and characterization of a discontinuous fiber-reinforced thermoset in the form of sheet molding compound (SMC). A microstructure-based parameter identification scheme for SMC with an inhomogeneous fiber orientation distribution is introduced. Different cruciform specimen designs, including two concepts to reinforce the specimens' arms are evaluated. Additionally, a micromechanical mean-field damage model for the SMC is introduced. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.

Thermomechanical Mean-Field Modeling and Experimental Characterization of Long Fiber-Reinforced Sheet Molding Compound Composites

Thermomechanical Mean-Field Modeling and Experimental Characterization of Long Fiber-Reinforced Sheet Molding Compound Composites
Author: Kehrer, Maria Loredana
Publisher: KIT Scientific Publishing
Total Pages: 204
Release: 2019-06-13
Genre: Technology & Engineering
ISBN: 3731509245

A discontinuous fiber-reinforced thermoset material produced by the Sheet Molding Compound process is investigated. Due to the process-related fiber orientation distribution, a composite with an anisotropic microstructure is created which crucially affects the mechanical properties. The central objectives are the modeling of the thermoelastic behavior of the composite accounting for the underlying microstructure, and the experimental characterization of the pure resin and the composite material.

Thermomechanical Modeling and Experimental Characterization of Sheet Molding Compound Composites

Thermomechanical Modeling and Experimental Characterization of Sheet Molding Compound Composites
Author: Lang, Juliane
Publisher: KIT Scientific Publishing
Total 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.

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

Fiber Orientation Tensors and Mean Field Homogenization: Application to Sheet Molding Compound
Author: Bauer, Julian Karl
Publisher: KIT Scientific Publishing
Total Pages: 252
Release: 2023-02-27
Genre: Technology & Engineering
ISBN: 3731512629

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.

Microstructure generation and micromechanical modeling of sheet molding compound composites

Microstructure generation and micromechanical modeling of sheet molding compound composites
Author: Görthofer, Johannes
Publisher: KIT Scientific Publishing
Total 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.

A Gradient Crystal Plasticity Theory Based on an Extended Energy Balance

A Gradient Crystal Plasticity Theory Based on an Extended Energy Balance
Author: Prahs, Andreas
Publisher: KIT Scientific Publishing
Total Pages: 182
Release: 2020-09-15
Genre: Technology & Engineering
ISBN: 3731510251

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 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
Author: Ruck, Johannes
Publisher: KIT Scientific Publishing
Total 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.

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
Author: Albiez, Jürgen
Publisher: KIT Scientific Publishing
Total Pages: 222
Release: 2019-05-22
Genre: Technology & Engineering
ISBN: 3731509180

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.