{"id":{"repo_id":"texas","oai_identifier":"oai:repositories.lib.utexas.edu:2152/116532"},"canonical_url":"https://search.dev.ndltd.org/etd/texas/oai:repositories.lib.utexas.edu:2152/116532","repository":{"repo_id":"texas","name":"University of Texas","base_url":"https://repositories.lib.utexas.edu/server/oai/request"},"display":{"title":"Refined design expressions for in-plane girder stiffness and system buckling capacity","abstract":"Lateral-torsional buckling at the system level (global buckling) has been the subject of several research studies over the past 20 years. This buckling mode often controls over conventional lateral-torsional buckling (buckling between braces points) when the girder system is long and narrow. One of the primary contributors to global buckling resistance is the in-plane girder stiffness of the system. There is, currently, a published expression for the in-plane girder stiffness; however, recent attempts to employ this expression in more unique design situations, such as in lean-on bracing systems, have raised some questions about its efficiency. The current expression accounts only for the stiffness contribution of the two exterior girders. Though this is a conservative approach, it can, in some cases, be considered overly conservative. The primary focus of this thesis study was to derive a more broadly applicable in-plane girder stiffness expression. To that end, a new expression for the system buckling capacity, that accounts for any number of girders, was derived. This system buckling capacity expression was then used to develop an in-plane girder stiffness expression that also accounts for any number of girders. A computational study, using the program mBrace3D, was performed to determine the accuracy of the proposed expressions. These computational study models included four separate girder sections and system widths ranging from two to ten girders. Other parameters investigated in this study were number of brace points along the girder, girder spacing, and the stiffness of the braces themselves.","abstract_html":"Lateral-torsional buckling at the system level (global buckling) has been the subject of several research studies over the past 20 years. This buckling mode often controls over conventional lateral-torsional buckling (buckling between braces points) when the girder system is long and narrow. One of the primary contributors to global buckling resistance is the in-plane girder stiffness of the system. There is, currently, a published expression for the in-plane girder stiffness; however, recent attempts to employ this expression in more unique design situations, such as in lean-on bracing systems, have raised some questions about its efficiency. The current expression accounts only for the stiffness contribution of the two exterior girders. Though this is a conservative approach, it can, in some cases, be considered overly conservative. The primary focus of this thesis study was to derive a more broadly applicable in-plane girder stiffness expression. To that end, a new expression for the system buckling capacity, that accounts for any number of girders, was derived. This system buckling capacity expression was then used to develop an in-plane girder stiffness expression that also accounts for any number of girders. A computational study, using the program mBrace3D, was performed to determine the accuracy of the proposed expressions. These computational study models included four separate girder sections and system widths ranging from two to ten girders. Other parameters investigated in this study were number of brace points along the girder, girder spacing, and the stiffness of the braces themselves.","abstract_has_math":false,"creators":["Fish, David John"],"institution":"The University of Texas at Austin","degree_name":"Master of Science in Engineering","degree_level":"Masters","degree_discipline":"Civil Engineering","degree_department":null,"school":null,"contributors":[],"advisors":["Helwig, Todd Aaron, 1965-"],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021-12-03","date_published":"2021-12-03","updated_at":"2026-07-24T05:01:24Z","subjects":["In-plane girder stiffness","Global buckling","System buckling"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://dx.doi.org/10.26153/tsw/43427"],"render_values":[{"text":"http://dx.doi.org/10.26153/tsw/43427","href":"http://dx.doi.org/10.26153/tsw/43427","code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/2152/116532","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Helwig, Todd Aaron, 1965-"]},{"key":"dc:creator","label":"Author","values":["Fish, David John"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2022-11-04T22:11:07Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-11-04T22:11:07Z"]},{"key":"dc:date.issued","label":"Date","values":["2021-12-03"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Civil Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science in Engineering"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["The University of Texas at Austin"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["In-plane girder stiffness","Global buckling","System buckling"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/2152/116532","http://dx.doi.org/10.26153/tsw/43427"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Lateral-torsional buckling at the system level (global buckling) has been the subject of several research studies over the past 20 years. This buckling mode often controls over conventional lateral-torsional buckling (buckling between braces points) when the girder system is long and narrow. One of the primary contributors to global buckling resistance is the in-plane girder stiffness of the system. There is, currently, a published expression for the in-plane girder stiffness; however, recent attempts to employ this expression in more unique design situations, such as in lean-on bracing systems, have raised some questions about its efficiency. The current expression accounts only for the stiffness contribution of the two exterior girders. Though this is a conservative approach, it can, in some cases, be considered overly conservative. The primary focus of this thesis study was to derive a more broadly applicable in-plane girder stiffness expression. To that end, a new expression for the system buckling capacity, that accounts for any number of girders, was derived. This system buckling capacity expression was then used to develop an in-plane girder stiffness expression that also accounts for any number of girders. A computational study, using the program mBrace3D, was performed to determine the accuracy of the proposed expressions. These computational study models included four separate girder sections and system widths ranging from two to ten girders. Other parameters investigated in this study were number of brace points along the girder, girder spacing, and the stiffness of the braces themselves."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Refined design expressions for in-plane girder stiffness and system buckling capacity"]}]}],"canonical_facts":{"dc:contributor.advisor":["Helwig, Todd Aaron, 1965-"],"dc:creator":["Fish, David John"],"dc:date.accessioned":["2022-11-04T22:11:07Z"],"dc:date.available":["2022-11-04T22:11:07Z"],"dc:date.issued":["2021-12-03"],"dc:description.abstract":["Lateral-torsional buckling at the system level (global buckling) has been the subject of several research studies over the past 20 years. This buckling mode often controls over conventional lateral-torsional buckling (buckling between braces points) when the girder system is long and narrow. One of the primary contributors to global buckling resistance is the in-plane girder stiffness of the system. There is, currently, a published expression for the in-plane girder stiffness; however, recent attempts to employ this expression in more unique design situations, such as in lean-on bracing systems, have raised some questions about its efficiency. The current expression accounts only for the stiffness contribution of the two exterior girders. Though this is a conservative approach, it can, in some cases, be considered overly conservative. The primary focus of this thesis study was to derive a more broadly applicable in-plane girder stiffness expression. To that end, a new expression for the system buckling capacity, that accounts for any number of girders, was derived. This system buckling capacity expression was then used to develop an in-plane girder stiffness expression that also accounts for any number of girders. A computational study, using the program mBrace3D, was performed to determine the accuracy of the proposed expressions. These computational study models included four separate girder sections and system widths ranging from two to ten girders. Other parameters investigated in this study were number of brace points along the girder, girder spacing, and the stiffness of the braces themselves."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["https://hdl.handle.net/2152/116532","http://dx.doi.org/10.26153/tsw/43427"],"dc:language.iso":["en"],"dc:subject":["In-plane girder stiffness","Global buckling","System buckling"],"dc:title":["Refined design expressions for in-plane girder stiffness and system buckling capacity"],"dc:type":["Thesis"],"thesis:degree_discipline":["Civil Engineering"],"thesis:degree_level":["Masters"],"thesis:degree_name":["Master of Science in Engineering"],"thesis:institution_name":["The University of Texas at Austin"]},"updated_at":"2026-07-24T05:01:24Z"}