Simplified limit load determination for integrity assessment
Thesis (Ph.D.)--Memorial University of Newfoundland, 2007. Engineering and Applied Science Includes bibliographical references (leaves 281-300) The codes and standards in the pressure vessels and piping areas of the energy, petrochemical and related industries are based on the identification of pote...
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ftmemorialunivdc:oai:collections.mun.ca:theses4/83937 2023-05-15T17:23:33+02:00 Simplified limit load determination for integrity assessment Adibi-Asl, Reza, 1976- Memorial University of Newfoundland. Faculty of Engineering and Applied Science 2008. xxiii, 328 leaves : ill. Image/jpeg; Application/pdf http://collections.mun.ca/cdm/ref/collection/theses4/id/83937 Eng eng Electronic Theses and Dissertations (30.81 MB) -- http://collections.mun.ca/PDFs/theses/AdibiAsl_Reza.pdf a2562076 http://collections.mun.ca/cdm/ref/collection/theses4/id/83937 The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries Fracture mechanics Structural analysis (Engineering) Text Electronic thesis or dissertation 2008 ftmemorialunivdc 2015-08-06T19:22:11Z Thesis (Ph.D.)--Memorial University of Newfoundland, 2007. Engineering and Applied Science Includes bibliographical references (leaves 281-300) The codes and standards in the pressure vessels and piping areas of the energy, petrochemical and related industries are based on the identification of potential modes of failures and a strategy for their avoidance. Instantaneous failures, specifically limit state and fast fracture, in the components and structures, can lead to catastrophic events. Therefore, integrity assessment of components and structures is required. -- Inelastic finite element method is widely used to conduct failure analysis. However, it can often be complicated, time consuming and expensive. As well, accurate results are dependent on the specification of adequate mesh density and an assurance of numerically stable solutions. Independent verification methods that are alternatives to inelastic finite element methods are often required for engineering designs. The methods discussed in this thesis, based on elastic modulus adjustment procedures (EMAP), provide rapid and stable solutions at a relatively lower cost. -- The elastic modulus adjustment methods rely on the convergence of the specific moduli adjustment procedure. A criterion for assessing the degree of convergence of EMAP is developed, and a procedure for achieving improved convergence is studied in this thesis. Also, simplified methods are developed in order to estimate the limit load in components and structures using iterative linear elastic methods. One of these procedures is the concept of reference volume that can be used to identify the kinematically active volume and dead zones in the components or structures. The reference volume method is shown to give a more accurate prediction of limit loads comparing to available traditional methods based on total volume. Furthermore, by invoking the concept of reference volume the systematic procedures are proposed to estimate the lower bound limit load solutions with high accuracy. This is very helpful for limit load analysis of the components/structures with stress razors such as notches and cracks. -- The concept of equivalence of "static indeterminacy" that relates a multidimensional component configuration to a "reference two-bar structure" is introduced for rapid estimation of the limit loads in components or structures. The procedures and methods discussed in this thesis are applied to some practical components (including cracks and notches) in order to verify their effectiveness in analyzing different geometries. Based on the proposed methods, integrity assessment analysis of different crack configurations, including multiple cracks and three dimensional effects, are studied in this thesis. Thesis Newfoundland studies University of Newfoundland Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
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English |
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Fracture mechanics Structural analysis (Engineering) |
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Fracture mechanics Structural analysis (Engineering) Adibi-Asl, Reza, 1976- Simplified limit load determination for integrity assessment |
topic_facet |
Fracture mechanics Structural analysis (Engineering) |
description |
Thesis (Ph.D.)--Memorial University of Newfoundland, 2007. Engineering and Applied Science Includes bibliographical references (leaves 281-300) The codes and standards in the pressure vessels and piping areas of the energy, petrochemical and related industries are based on the identification of potential modes of failures and a strategy for their avoidance. Instantaneous failures, specifically limit state and fast fracture, in the components and structures, can lead to catastrophic events. Therefore, integrity assessment of components and structures is required. -- Inelastic finite element method is widely used to conduct failure analysis. However, it can often be complicated, time consuming and expensive. As well, accurate results are dependent on the specification of adequate mesh density and an assurance of numerically stable solutions. Independent verification methods that are alternatives to inelastic finite element methods are often required for engineering designs. The methods discussed in this thesis, based on elastic modulus adjustment procedures (EMAP), provide rapid and stable solutions at a relatively lower cost. -- The elastic modulus adjustment methods rely on the convergence of the specific moduli adjustment procedure. A criterion for assessing the degree of convergence of EMAP is developed, and a procedure for achieving improved convergence is studied in this thesis. Also, simplified methods are developed in order to estimate the limit load in components and structures using iterative linear elastic methods. One of these procedures is the concept of reference volume that can be used to identify the kinematically active volume and dead zones in the components or structures. The reference volume method is shown to give a more accurate prediction of limit loads comparing to available traditional methods based on total volume. Furthermore, by invoking the concept of reference volume the systematic procedures are proposed to estimate the lower bound limit load solutions with high accuracy. This is very helpful for limit load analysis of the components/structures with stress razors such as notches and cracks. -- The concept of equivalence of "static indeterminacy" that relates a multidimensional component configuration to a "reference two-bar structure" is introduced for rapid estimation of the limit loads in components or structures. The procedures and methods discussed in this thesis are applied to some practical components (including cracks and notches) in order to verify their effectiveness in analyzing different geometries. Based on the proposed methods, integrity assessment analysis of different crack configurations, including multiple cracks and three dimensional effects, are studied in this thesis. |
author2 |
Memorial University of Newfoundland. Faculty of Engineering and Applied Science |
format |
Thesis |
author |
Adibi-Asl, Reza, 1976- |
author_facet |
Adibi-Asl, Reza, 1976- |
author_sort |
Adibi-Asl, Reza, 1976- |
title |
Simplified limit load determination for integrity assessment |
title_short |
Simplified limit load determination for integrity assessment |
title_full |
Simplified limit load determination for integrity assessment |
title_fullStr |
Simplified limit load determination for integrity assessment |
title_full_unstemmed |
Simplified limit load determination for integrity assessment |
title_sort |
simplified limit load determination for integrity assessment |
publishDate |
2008 |
url |
http://collections.mun.ca/cdm/ref/collection/theses4/id/83937 |
genre |
Newfoundland studies University of Newfoundland |
genre_facet |
Newfoundland studies University of Newfoundland |
op_source |
Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries |
op_relation |
Electronic Theses and Dissertations (30.81 MB) -- http://collections.mun.ca/PDFs/theses/AdibiAsl_Reza.pdf a2562076 http://collections.mun.ca/cdm/ref/collection/theses4/id/83937 |
op_rights |
The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. |
_version_ |
1766113275601223680 |