Micro-crack interactions and shape design optimization problems: A boundary element approach.

Persistent Link:
http://hdl.handle.net/10150/186899
Title:
Micro-crack interactions and shape design optimization problems: A boundary element approach.
Author:
Wei, Xin.
Issue Date:
1994
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Most materials contain micro-scale features e.g., cracks, inclusions, secondary phases and their interfaces. The strength and life of macro-scale components fabricated from these materials essentially depend on the interactions and evolutions of associated micro-features. In the first part of this dissertation, a hybrid micro-macro Boundary Element Method (BEM) formulation is developed to capture the micro-scale effects, effectively and efficiently, within the context of a macro-scale analysis. The micro-scale effects are introduced through an augmented fundamental solution, and the effects of macro-scale design considerations on micro-scale evolutions are investigated through the hybrid BEM approach. A unit cell model in conjunction with the hybrid BEM approach is also developed to obtain effective homogenized material properties for these heterogeneous materials. Numerical results obtained from the proposed hybrid BEM scheme are compared to existing analytical and numerical results. Investigation of design sensitivities and optimization with respect to various geometric, material and process parameters is the focus of the second part of this dissertation. A direct differentiation approach is pursued for this purpose and numerical results are presented for small strain elasto-viscoplastic problems. Shape optimization is carried out by coupling the standard and sensitivity analyses with an optimizer. Numerical results are presented for various homogenized media and are also compared to known solutions for this class of problems.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Aerospace and Mechanical Engineering; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Chandra, Abhijit

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleMicro-crack interactions and shape design optimization problems: A boundary element approach.en_US
dc.creatorWei, Xin.en_US
dc.contributor.authorWei, Xin.en_US
dc.date.issued1994en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractMost materials contain micro-scale features e.g., cracks, inclusions, secondary phases and their interfaces. The strength and life of macro-scale components fabricated from these materials essentially depend on the interactions and evolutions of associated micro-features. In the first part of this dissertation, a hybrid micro-macro Boundary Element Method (BEM) formulation is developed to capture the micro-scale effects, effectively and efficiently, within the context of a macro-scale analysis. The micro-scale effects are introduced through an augmented fundamental solution, and the effects of macro-scale design considerations on micro-scale evolutions are investigated through the hybrid BEM approach. A unit cell model in conjunction with the hybrid BEM approach is also developed to obtain effective homogenized material properties for these heterogeneous materials. Numerical results obtained from the proposed hybrid BEM scheme are compared to existing analytical and numerical results. Investigation of design sensitivities and optimization with respect to various geometric, material and process parameters is the focus of the second part of this dissertation. A direct differentiation approach is pursued for this purpose and numerical results are presented for small strain elasto-viscoplastic problems. Shape optimization is carried out by coupling the standard and sensitivity analyses with an optimizer. Numerical results are presented for various homogenized media and are also compared to known solutions for this class of problems.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAerospace and Mechanical Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairChandra, Abhijiten_US
dc.contributor.committeememberHuang, Youngen_US
dc.contributor.committeememberMadenci, Erdoganen_US
dc.contributor.committeememberChan, Choliken_US
dc.identifier.proquest9517515en_US
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