{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/21624"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/21624","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"A study of the buckling behavior of stiffened composite shells","abstract":"Restriction data tranferred 2014-07-01T11:23:57-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","abstract_html":"Restriction data tranferred 2014-07-01T11:23:57-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","abstract_has_math":false,"creators":["Moradi, Behrooz"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Civil Engineering","degree_department":null,"school":null,"contributors":["Parsons, I. Dennis"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:14:15Z","date_published":"2011-05-07T13:14:15Z","updated_at":"2026-07-22T22:25:18Z","subjects":["Engineering, Civil"],"languages":["eng"],"rights":["Copyright 1992 Moradi, Behrooz"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9305624","(UMI)AAI9305624"],"render_values":[{"text":"AAI9305624","href":null,"code":true},{"text":"(UMI)AAI9305624","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/21624","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Parsons, I. Dennis"]},{"key":"dc:creator","label":"Author","values":["Moradi, Behrooz"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:14:15Z","10000-01-01","1992"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Civil Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Civil"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1992 Moradi, Behrooz"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9305624","(UMI)AAI9305624","http://hdl.handle.net/2142/21624"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Restriction data tranferred 2014-07-01T11:23:57-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","Studies are reported that examine the buckling behavior of stiffened composite shells. First, dimensional analysis is applied to a simple model of stiffened laminated cylindrical shells to determine the dimensionless parameters that characterize the buckling of these structures. Donnell shell theory is used to describe the kinematic deformation of the shells. The axial and ring stiffeners are modeled using the smeared technique. A nondimensional load is defined as a function of nine nondimensional parameters which are a combination of the material and geometric properties of the shell. Additional assumptions regarding the construction of the shell walls can be used to reduce the number of nondimensional parameters. Some simply-supported shells subjected to hydrostatic pressure are examined to demonstrate the use of the dimensionless parameters. Estimates of the imperfection sensitivity of these shells are made using Koiter's asymptotic theory. The dimensional analysis provides a framework for the systematic investigation of the effect changes in material and geometry have on the buckling loads of stiffened composite shells. The results of this analysis are intended to provide information that can be used in the preliminary stages of a shell design.","Second, an investigation is made into the accuracy of different methods that are commonly used to numerically compute the buckling loads of stiffened shells. Three different methods are employed to estimate the buckling loads of several ring stiffened cylindrical shells and shells made of orthotropic material. These methods are a nonlinear bifurcation analysis and two linearized buckling analyses, one that ignores the initial displacement stiffness matrix, and one that includes it. Large differences are observed between the predictions made by the two linearized buckling analyses for a range of shell geometries. Detailed studies of a shell with six ring stiffeners demonstrate that these differences are caused by the different versions of the linearized eigenvalue problem, rather than by the use of different numerical formulations. Investigations of the prebuckling behavior of this cylinder show that significant nonlinear deformations occur. This means that a nonlinear bifurcation analysis must be used to accurately estimate the buckling load of this geometrically perfect shell.","Made available in DSpace on 2011-05-07T13:14:15Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9305624.pdf: 3520601 bytes, checksum: dcf3869b3de181133ddef84fe58595be (MD5) Previous issue date: 1992","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:52:06Z Item is restricted indefinitely.","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["A study of the buckling behavior of stiffened composite shells"]}]}],"canonical_facts":{"dc:contributor":["Parsons, I. Dennis"],"dc:creator":["Moradi, Behrooz"],"dc:date":["2011-05-07T13:14:15Z","10000-01-01","1992"],"dc:description":["Restriction data tranferred 2014-07-01T11:23:57-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","Studies are reported that examine the buckling behavior of stiffened composite shells. First, dimensional analysis is applied to a simple model of stiffened laminated cylindrical shells to determine the dimensionless parameters that characterize the buckling of these structures. Donnell shell theory is used to describe the kinematic deformation of the shells. The axial and ring stiffeners are modeled using the smeared technique. A nondimensional load is defined as a function of nine nondimensional parameters which are a combination of the material and geometric properties of the shell. Additional assumptions regarding the construction of the shell walls can be used to reduce the number of nondimensional parameters. Some simply-supported shells subjected to hydrostatic pressure are examined to demonstrate the use of the dimensionless parameters. Estimates of the imperfection sensitivity of these shells are made using Koiter's asymptotic theory. The dimensional analysis provides a framework for the systematic investigation of the effect changes in material and geometry have on the buckling loads of stiffened composite shells. The results of this analysis are intended to provide information that can be used in the preliminary stages of a shell design.","Second, an investigation is made into the accuracy of different methods that are commonly used to numerically compute the buckling loads of stiffened shells. Three different methods are employed to estimate the buckling loads of several ring stiffened cylindrical shells and shells made of orthotropic material. These methods are a nonlinear bifurcation analysis and two linearized buckling analyses, one that ignores the initial displacement stiffness matrix, and one that includes it. Large differences are observed between the predictions made by the two linearized buckling analyses for a range of shell geometries. Detailed studies of a shell with six ring stiffeners demonstrate that these differences are caused by the different versions of the linearized eigenvalue problem, rather than by the use of different numerical formulations. Investigations of the prebuckling behavior of this cylinder show that significant nonlinear deformations occur. This means that a nonlinear bifurcation analysis must be used to accurately estimate the buckling load of this geometrically perfect shell.","Made available in DSpace on 2011-05-07T13:14:15Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9305624.pdf: 3520601 bytes, checksum: dcf3869b3de181133ddef84fe58595be (MD5) Previous issue date: 1992","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:52:06Z Item is restricted indefinitely.","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9305624","(UMI)AAI9305624","http://hdl.handle.net/2142/21624"],"dc:language":["eng"],"dc:rights":["Copyright 1992 Moradi, Behrooz"],"dc:subject":["Engineering, Civil"],"dc:title":["A study of the buckling behavior of stiffened composite shells"],"dc:type":["text"],"thesis:degree_discipline":["Civil Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:18Z"}