{"id":{"repo_id":"ku","oai_identifier":"oai:kuscholarworks.ku.edu:1808/10194"},"canonical_url":"https://search.dev.ndltd.org/etd/ku/oai:kuscholarworks.ku.edu:1808/10194","repository":{"repo_id":"ku","name":"University of Kansas","base_url":"https://kuscholarworks.ku.edu/server/oai/request"},"display":{"title":"Repair of Steel Bridge Girders Damaged by Distortion-Induced Fatigue","abstract":"Several studies have identified distortion-induced fatigue as the leading cause of cracks in steel bridges built prior to the mid-1980s. Experimental and computer simulations of 914-mm (36-in.) deep girder-cross frame subassemblies subjected to cyclic loading were carried out to study the effects of distortion-induced fatigue and to evaluate the effectiveness of various retrofit measures. Previous repair methods for distortion-induced fatigue damage have attempted to reduce the stress demand at the critical web-gap region by increasing the flexibility of the girder web in the out-of-plane direction or by restraining the lateral motion of the web by fixing the connection stiffener to the girder flange. A new approach was investigated in this study intended to reduce the stress demand in the web-gap region by re-distributing the out-of-plane force transferred through the girder-cross frame connection over a larger area of the girder web. A new retrofit measure is proposed based on this approach, which consists of adding steel angles connecting the girder web and the connection plate (CP), and a steel plate on the back side of the girder web to distribute the lateral force over a wider region of the web. Experimental and computer simulation results are presented showing that this repair method is very effective in preventing the growth of horseshoe-shaped cracks around the web cross-frame connection and of horizontal cracks near the junction between the flange and web.","abstract_html":"Several studies have identified distortion-induced fatigue as the leading cause of cracks in steel bridges built prior to the mid-1980s. Experimental and computer simulations of 914-mm (36-in.) deep girder-cross frame subassemblies subjected to cyclic loading were carried out to study the effects of distortion-induced fatigue and to evaluate the effectiveness of various retrofit measures. Previous repair methods for distortion-induced fatigue damage have attempted to reduce the stress demand at the critical web-gap region by increasing the flexibility of the girder web in the out-of-plane direction or by restraining the lateral motion of the web by fixing the connection stiffener to the girder flange. A new approach was investigated in this study intended to reduce the stress demand in the web-gap region by re-distributing the out-of-plane force transferred through the girder-cross frame connection over a larger area of the girder web. A new retrofit measure is proposed based on this approach, which consists of adding steel angles connecting the girder web and the connection plate (CP), and a steel plate on the back side of the girder web to distribute the lateral force over a wider region of the web. Experimental and computer simulation results are presented showing that this repair method is very effective in preventing the growth of horseshoe-shaped cracks around the web cross-frame connection and of horizontal cracks near the junction between the flange and web.","abstract_has_math":false,"creators":["Nagati, Amr Daniel"],"institution":"University of Kansas","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Bennett, Caroline R.","Matamoros, Adolfo"],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-08-31","date_published":"2012-08-31","updated_at":"2026-07-24T02:44:56Z","subjects":["Civil engineering","Bridge","Cfrp","Distortion","Fatigue","Load cell","Retrofit"],"languages":["en"],"rights":["This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["http://dissertations.umi.com/ku:12266"],"render_values":[{"text":"http://dissertations.umi.com/ku:12266","href":"http://dissertations.umi.com/ku:12266","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/1808/10194","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Bennett, Caroline R.","Matamoros, Adolfo"]},{"key":"dc:creator","label":"Author","values":["Nagati, Amr Daniel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2012-10-27T09:59:24Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2012-10-27T09:59:24Z"]},{"key":"dc:date.issued","label":"Date","values":["2012-08-31"]},{"key":"dc:publisher","label":"Institution","values":["University of Kansas"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Civil engineering","Bridge","Cfrp","Distortion","Fatigue","Load cell","Retrofit"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["http://dissertations.umi.com/ku:12266"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1808/10194"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Several studies have identified distortion-induced fatigue as the leading cause of cracks in steel bridges built prior to the mid-1980s. Experimental and computer simulations of 914-mm (36-in.) deep girder-cross frame subassemblies subjected to cyclic loading were carried out to study the effects of distortion-induced fatigue and to evaluate the effectiveness of various retrofit measures. Previous repair methods for distortion-induced fatigue damage have attempted to reduce the stress demand at the critical web-gap region by increasing the flexibility of the girder web in the out-of-plane direction or by restraining the lateral motion of the web by fixing the connection stiffener to the girder flange. A new approach was investigated in this study intended to reduce the stress demand in the web-gap region by re-distributing the out-of-plane force transferred through the girder-cross frame connection over a larger area of the girder web. A new retrofit measure is proposed based on this approach, which consists of adding steel angles connecting the girder web and the connection plate (CP), and a steel plate on the back side of the girder web to distribute the lateral force over a wider region of the web. Experimental and computer simulation results are presented showing that this repair method is very effective in preventing the growth of horseshoe-shaped cracks around the web cross-frame connection and of horizontal cracks near the junction between the flange and web."]},{"key":"dc:title","label":"Title","values":["Repair of Steel Bridge Girders Damaged by Distortion-Induced Fatigue"]}]}],"canonical_facts":{"dc:contributor.advisor":["Bennett, Caroline R.","Matamoros, Adolfo"],"dc:creator":["Nagati, Amr Daniel"],"dc:date.accessioned":["2012-10-27T09:59:24Z"],"dc:date.available":["2012-10-27T09:59:24Z"],"dc:date.issued":["2012-08-31"],"dc:description.abstract":["Several studies have identified distortion-induced fatigue as the leading cause of cracks in steel bridges built prior to the mid-1980s. Experimental and computer simulations of 914-mm (36-in.) deep girder-cross frame subassemblies subjected to cyclic loading were carried out to study the effects of distortion-induced fatigue and to evaluate the effectiveness of various retrofit measures. Previous repair methods for distortion-induced fatigue damage have attempted to reduce the stress demand at the critical web-gap region by increasing the flexibility of the girder web in the out-of-plane direction or by restraining the lateral motion of the web by fixing the connection stiffener to the girder flange. A new approach was investigated in this study intended to reduce the stress demand in the web-gap region by re-distributing the out-of-plane force transferred through the girder-cross frame connection over a larger area of the girder web. A new retrofit measure is proposed based on this approach, which consists of adding steel angles connecting the girder web and the connection plate (CP), and a steel plate on the back side of the girder web to distribute the lateral force over a wider region of the web. Experimental and computer simulation results are presented showing that this repair method is very effective in preventing the growth of horseshoe-shaped cracks around the web cross-frame connection and of horizontal cracks near the junction between the flange and web."],"dc:identifier.other":["http://dissertations.umi.com/ku:12266"],"dc:identifier.uri":["http://hdl.handle.net/1808/10194"],"dc:language.iso":["en"],"dc:publisher":["University of Kansas"],"dc:rights":["This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author."],"dc:subject":["Civil engineering","Bridge","Cfrp","Distortion","Fatigue","Load cell","Retrofit"],"dc:title":["Repair of Steel Bridge Girders Damaged by Distortion-Induced Fatigue"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T02:44:56Z"}