Title Information
Title
Microscale Modeling of Deformation Response of Advanced High Strength Steels and Mechanical Behavior of Active Biopolymer Networks
Name: Personal
Name Part
chen, peng
Role
Role Term: Text
creator
Origin Information
Copyright Date
2013
Physical Description
Extent
xx, 127 p.
digitalOrigin
born digital
Note
Thesis (Ph.D. -- Brown University (2013)
Name: Personal
Name Part
Bower, Allan
Role
Role Term: Text
Director
Name: Personal
Name Part
Kim, Kyung-Suk
Role
Role Term: Text
Reader
Name: Personal
Name Part
Kumar, Sharvan
Role
Role Term: Text
Reader
Name: Personal
Name Part
Hector, Louis
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. ENGINEERING: Mechanics of Solids
Role
Role Term: Text
sponsor
Genre (aat)
theses
Abstract
The nonlinear deformation response of two distinct materials was studied using finite element simulations. One is the hard Advanced High Strength Steels (AHSS) widely used in automobile vehicles. Another is the soft active biopolymer networks in plant and animal cells. For the hard AHSS, our proposed approach has successfully modeled the deformation response of two types of AHSS: fully martensitic steel and dual-phase steels. The measured flow curves for the martensite micropillars in the size-independent regime were used to determine material parameters in a dislocation-density-based crystal plasticity model of individual martensite blocks. The crystallographic orientation dependence of the flow strength in the ferritic micropillars was predicted successfully by a crystal plasticity model that accounts for the non-Schmid behavior. Full 3D crystal plasticity simulations, with material properties determined from micropillar compression tests, were then used to predict the macroscopic uniaxial stress–strain curves of the fully martensitic steel and dual-phase steels, which were in excellent agreement with experimental measurements. For the soft active biopolymer networks, we have studied the elastic response of actin networks with both compliant and rigid crosslinks by modeling molecular motors as force dipoles. Our finite element simulations show that for compliant crosslinkers such as filamin A, the network can be stiffened by two orders of magnitude while stiffening achieved with incompliant linkers such as scruin is significantly smaller, typically a factor of two, in excellent agreement with recent experiments. We show that the differences arise from the fact that the motors are able to stretch the compliant crosslinks to the fullest possible extent, which in turn causes to the deformation of the filaments. With increasing applied strain, the filaments further deform leading to a stiffened elastic response. When the crosslinks are incompliant, the contractile forces due to motors do not alter the network morphology in a significant manner and hence only small stiffening is observed.
Subject
Topic
Low-carbon martensite
Subject
Topic
Dual-phase steels
Subject
Topic
Deformation
Subject
Topic
Micropillar
Subject
Topic
Finite element modeling
Subject
Topic
Active biopolymer networks
Subject
Topic
Crosslinks
Subject
Topic
Molecular motor
Subject
Topic
Strain stiffening
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1020118")
Topic
Microstructure
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20141006
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z0639N24
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations