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Evolution of Anisotropy in Continua Exposed to Large Strains

Harrysson, Magnus LU (2008)
Abstract
This thesis deals with the modeling of anisotropic materials at finite deformations. The major emphasis is the development of constitutive models able to account for the evolving directionally dependent properties of these materials. In addition, the numerical implementation of the models developed is addressed. In particular, the following topics are considered.



To model finite elasto-plastic deformations use is made of the multiplicative split of the deformation gradient in which an intermediate configuration is introduced. Issues related to this intermediate configuration when considering an anisotropic setting are investigated and discussed.

A spatial description of elasto-plastic anisotropic material is... (More)
This thesis deals with the modeling of anisotropic materials at finite deformations. The major emphasis is the development of constitutive models able to account for the evolving directionally dependent properties of these materials. In addition, the numerical implementation of the models developed is addressed. In particular, the following topics are considered.



To model finite elasto-plastic deformations use is made of the multiplicative split of the deformation gradient in which an intermediate configuration is introduced. Issues related to this intermediate configuration when considering an anisotropic setting are investigated and discussed.

A spatial description of elasto-plastic anisotropic material is developed. The capabilities of the model are investigated where an example involving the drawing process of a cup is considered.



Different approaches for the modeling of evolving anisotropic material behavior have been reported in the literature. Two of these approaches are investigated and compared, both analytical results and numerical examples being considered.



Soft biological tissues, such as blood vessels and skin show anisotropic material behavior. An orientation distribution-based formulation is developed where the anisotropy is accounted for by the non-uniform orientation distribution of the collagen fibers. The evolution of anisotropic properties in soft biological tissue is also considered by introduction of an evolution law for the direction of the collagen fibers.



Glassy polymers consist of individual polymer chains in which the orientation of the chains affects the anisotropic behavior of the material. An elastoviscoplastic material model which accounts for the orientation distribution of the polymer chains is proposed. The orientational averaging process involved is calculated by numerical integration over the unit sphere. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Mahnken, Rolf, University of Paderborn, Germany
organization
publishing date
type
Thesis
publication status
published
subject
defense location
Room M:E, M-building, Ole Römers väg 1, Lund university, Faculty of Engineering
defense date
2008-06-13 10:15
ISBN
978-91-628-7524-4
language
English
LU publication?
yes
id
371ddef0-a5d2-4c38-8995-6ba31be083ca (old id 1150914)
date added to LUP
2008-05-22 08:22:53
date last changed
2016-09-19 08:45:19
@misc{371ddef0-a5d2-4c38-8995-6ba31be083ca,
  abstract     = {This thesis deals with the modeling of anisotropic materials at finite deformations. The major emphasis is the development of constitutive models able to account for the evolving directionally dependent properties of these materials. In addition, the numerical implementation of the models developed is addressed. In particular, the following topics are considered.<br/><br>
<br/><br>
To model finite elasto-plastic deformations use is made of the multiplicative split of the deformation gradient in which an intermediate configuration is introduced. Issues related to this intermediate configuration when considering an anisotropic setting are investigated and discussed.<br/><br>
A spatial description of elasto-plastic anisotropic material is developed. The capabilities of the model are investigated where an example involving the drawing process of a cup is considered.<br/><br>
<br/><br>
Different approaches for the modeling of evolving anisotropic material behavior have been reported in the literature. Two of these approaches are investigated and compared, both analytical results and numerical examples being considered.<br/><br>
<br/><br>
Soft biological tissues, such as blood vessels and skin show anisotropic material behavior. An orientation distribution-based formulation is developed where the anisotropy is accounted for by the non-uniform orientation distribution of the collagen fibers. The evolution of anisotropic properties in soft biological tissue is also considered by introduction of an evolution law for the direction of the collagen fibers. <br/><br>
<br/><br>
Glassy polymers consist of individual polymer chains in which the orientation of the chains affects the anisotropic behavior of the material. An elastoviscoplastic material model which accounts for the orientation distribution of the polymer chains is proposed. The orientational averaging process involved is calculated by numerical integration over the unit sphere.},
  author       = {Harrysson, Magnus},
  isbn         = {978-91-628-7524-4},
  language     = {eng},
  title        = {Evolution of Anisotropy in Continua Exposed to Large Strains},
  year         = {2008},
}