{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/83167"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/83167","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Numerical Investigation of Cleavage Fracture in Welded Connections of Steel Moment Resistant Frames","abstract":"\"This study applies an advanced micro-mechanics model of cleavage fracture in ferritic steels to examine the behavior of welded, moment resistant steel frames of the type widely constructed prior to the 1994 Northridge earthquake. The Weibull stress model for cleavage, coupled with 3-D analyses of connections containing crack-like defects, provides a quantitative estimate of the cumulative failure probabilities with increasing beam moment. The 3-D models incorporate the complete geometry of a welded joint (access holes, shear tabs, continuity plate, weld geometry, backup bars). A set of previously conducted, 15 full-scale tests on T-connections of the pre-Northridge design (A36 beams, A572 columns, E70T-4 welds, backup bars left in place) provide fracture moments to calibrate parameters of the Weibull stress model. This study initially considers quasi-static loading typically imposed in large-scale testing of the connections. Once calibrated, the model is used here to examine the importance of welding induced residual stresses in the lower-flange weld, the effects of stronger (A572) beams and modified access hole geometries, and a variety of proposed changes in the weld detail (backup bars, fillet reinforcements). The model predicts the cumulative failure probability for these various configurations. Using this same approach, the simplified \"\"pull-plate\"\" specimen is examined from a fracture mechanics viewpoint as a suitable replacement for full connection testing to evaluate alternative welding details. The study concludes by investigating the increased probability of cleavage fracture due to dynamic loading rates of the levels expected during a strong seismic event.\"","abstract_html":""This study applies an advanced micro-mechanics model of cleavage fracture in ferritic steels to examine the behavior of welded, moment resistant steel frames of the type widely constructed prior to the 1994 Northridge earthquake. The Weibull stress model for cleavage, coupled with 3-D analyses of connections containing crack-like defects, provides a quantitative estimate of the cumulative failure probabilities with increasing beam moment. The 3-D models incorporate the complete geometry of a welded joint (access holes, shear tabs, continuity plate, weld geometry, backup bars). A set of previously conducted, 15 full-scale tests on T-connections of the pre-Northridge design (A36 beams, A572 columns, E70T-4 welds, backup bars left in place) provide fracture moments to calibrate parameters of the Weibull stress model. This study initially considers quasi-static loading typically imposed in large-scale testing of the connections. Once calibrated, the model is used here to examine the importance of welding induced residual stresses in the lower-flange weld, the effects of stronger (A572) beams and modified access hole geometries, and a variety of proposed changes in the weld detail (backup bars, fillet reinforcements). The model predicts the cumulative failure probability for these various configurations. Using this same approach, the simplified ""pull-plate"" specimen is examined from a fracture mechanics viewpoint as a suitable replacement for full connection testing to evaluate alternative welding details. The study concludes by investigating the increased probability of cleavage fracture due to dynamic loading rates of the levels expected during a strong seismic event."","abstract_has_math":false,"creators":["Matos, Carlos Gustavo"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Civil Engineering","degree_department":null,"school":null,"contributors":["Dodds, Robert H., Jr."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T21:03:12Z","date_published":"2015-09-25T21:03:12Z","updated_at":"2026-07-22T22:26:20Z","subjects":["Engineering, Civil"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI3023138"],"render_values":[{"text":"(MiAaPQ)AAI3023138","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/83167","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dodds, Robert H., Jr."]},{"key":"dc:creator","label":"Author","values":["Matos, Carlos Gustavo"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T21:03:12Z","10000-01-01","2001"]},{"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"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/83167","(MiAaPQ)AAI3023138"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["\"This study applies an advanced micro-mechanics model of cleavage fracture in ferritic steels to examine the behavior of welded, moment resistant steel frames of the type widely constructed prior to the 1994 Northridge earthquake. The Weibull stress model for cleavage, coupled with 3-D analyses of connections containing crack-like defects, provides a quantitative estimate of the cumulative failure probabilities with increasing beam moment. The 3-D models incorporate the complete geometry of a welded joint (access holes, shear tabs, continuity plate, weld geometry, backup bars). A set of previously conducted, 15 full-scale tests on T-connections of the pre-Northridge design (A36 beams, A572 columns, E70T-4 welds, backup bars left in place) provide fracture moments to calibrate parameters of the Weibull stress model. This study initially considers quasi-static loading typically imposed in large-scale testing of the connections. Once calibrated, the model is used here to examine the importance of welding induced residual stresses in the lower-flange weld, the effects of stronger (A572) beams and modified access hole geometries, and a variety of proposed changes in the weld detail (backup bars, fillet reinforcements). The model predicts the cumulative failure probability for these various configurations. Using this same approach, the simplified \"\"pull-plate\"\" specimen is examined from a fracture mechanics viewpoint as a suitable replacement for full connection testing to evaluate alternative welding details. The study concludes by investigating the increased probability of cleavage fracture due to dynamic loading rates of the levels expected during a strong seismic event.\"","Made available in DSpace on 2015-09-25T21:03:12Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3023138.pdf: 7638999 bytes, checksum: 3ccc23a299508c075efa86ed3548fea5 (MD5) Previous issue date: 2001","Embargo set by: Seth Robbins for item 84448 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","126 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2001."]},{"key":"dc:title","label":"Title","values":["Numerical Investigation of Cleavage Fracture in Welded Connections of Steel Moment Resistant Frames"]}]}],"canonical_facts":{"dc:contributor":["Dodds, Robert H., Jr."],"dc:creator":["Matos, Carlos Gustavo"],"dc:date":["2015-09-25T21:03:12Z","10000-01-01","2001"],"dc:description":["\"This study applies an advanced micro-mechanics model of cleavage fracture in ferritic steels to examine the behavior of welded, moment resistant steel frames of the type widely constructed prior to the 1994 Northridge earthquake. The Weibull stress model for cleavage, coupled with 3-D analyses of connections containing crack-like defects, provides a quantitative estimate of the cumulative failure probabilities with increasing beam moment. The 3-D models incorporate the complete geometry of a welded joint (access holes, shear tabs, continuity plate, weld geometry, backup bars). A set of previously conducted, 15 full-scale tests on T-connections of the pre-Northridge design (A36 beams, A572 columns, E70T-4 welds, backup bars left in place) provide fracture moments to calibrate parameters of the Weibull stress model. This study initially considers quasi-static loading typically imposed in large-scale testing of the connections. Once calibrated, the model is used here to examine the importance of welding induced residual stresses in the lower-flange weld, the effects of stronger (A572) beams and modified access hole geometries, and a variety of proposed changes in the weld detail (backup bars, fillet reinforcements). The model predicts the cumulative failure probability for these various configurations. Using this same approach, the simplified \"\"pull-plate\"\" specimen is examined from a fracture mechanics viewpoint as a suitable replacement for full connection testing to evaluate alternative welding details. The study concludes by investigating the increased probability of cleavage fracture due to dynamic loading rates of the levels expected during a strong seismic event.\"","Made available in DSpace on 2015-09-25T21:03:12Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3023138.pdf: 7638999 bytes, checksum: 3ccc23a299508c075efa86ed3548fea5 (MD5) Previous issue date: 2001","Embargo set by: Seth Robbins for item 84448 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","126 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2001."],"dc:identifier":["http://hdl.handle.net/2142/83167","(MiAaPQ)AAI3023138"],"dc:language":["eng"],"dc:subject":["Engineering, Civil"],"dc:title":["Numerical Investigation of Cleavage Fracture in Welded Connections of Steel Moment Resistant Frames"],"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":"2026-07-22T22:26:20Z"}