{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/71670"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/71670","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Dynamic Analysis of Interfacial Cracks in Composite Laminates","abstract":"The interfacial crack in composite laminates has been of great interest as composite materials are widely used today. In this paper, the order of dynamic stress singularity of interfacial cracks is derived, and a hybrid finite element method is successfully developed for this problem. Both the cases of open and closed cracks are considered. An integral transform, the Wiener-Hopf technique, and an asymptotic theory have been used for deriving the orders of stress singularity of interfacial cracks. The crack-tip elements in anisotropic materials are formulated by employing Lekhnitskii's stress functions and the variational principles of a hybrid functional. An iterative scheme for determining the closure size of a partially closed crack is proposed. Solutions for the orders of stress singularity of interfacial cracks in graphite-epoxy composites with different lamination variables and crack surface conditions agree well with the reference solutions. For the problem of an interfacial crack between two dissimilar anisotropic half spaces, finite element solutions are found very close to the exact solutions. Effects of element size, aspect ratio, and eigenfunction truncation of the crack-tip elements have been studied. Solutions for several delamination problems of practical interest are also presented by using hybrid crack-tip elements. Results of this study show that the Wiener-Hopf technique is a suitable method for investigating the dynamic behavior of interfacial cracks and that the hybrid crack-tip elements provide efficient and accurate numerical methods for studying delamination problems of composites.","abstract_html":"The interfacial crack in composite laminates has been of great interest as composite materials are widely used today. In this paper, the order of dynamic stress singularity of interfacial cracks is derived, and a hybrid finite element method is successfully developed for this problem. Both the cases of open and closed cracks are considered. An integral transform, the Wiener-Hopf technique, and an asymptotic theory have been used for deriving the orders of stress singularity of interfacial cracks. The crack-tip elements in anisotropic materials are formulated by employing Lekhnitskii's stress functions and the variational principles of a hybrid functional. An iterative scheme for determining the closure size of a partially closed crack is proposed. Solutions for the orders of stress singularity of interfacial cracks in graphite-epoxy composites with different lamination variables and crack surface conditions agree well with the reference solutions. For the problem of an interfacial crack between two dissimilar anisotropic half spaces, finite element solutions are found very close to the exact solutions. Effects of element size, aspect ratio, and eigenfunction truncation of the crack-tip elements have been studied. Solutions for several delamination problems of practical interest are also presented by using hybrid crack-tip elements. Results of this study show that the Wiener-Hopf technique is a suitable method for investigating the dynamic behavior of interfacial cracks and that the hybrid crack-tip elements provide efficient and accurate numerical methods for studying delamination problems of composites.","abstract_has_math":false,"creators":["Kuo, an-Yu"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Theoretical and Applied Mechanics","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-16T19:12:28Z","date_published":"2014-12-16T19:12:28Z","updated_at":"2026-07-22T22:26:05Z","subjects":["Applied Mechanics"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8302916"],"render_values":[{"text":"(UMI)AAI8302916","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/71670","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Kuo, an-Yu"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-16T19:12:28Z","10000-01-01","1982"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Theoretical and Applied Mechanics"]},{"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":["Applied Mechanics"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/71670","(UMI)AAI8302916"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The interfacial crack in composite laminates has been of great interest as composite materials are widely used today. In this paper, the order of dynamic stress singularity of interfacial cracks is derived, and a hybrid finite element method is successfully developed for this problem. Both the cases of open and closed cracks are considered. An integral transform, the Wiener-Hopf technique, and an asymptotic theory have been used for deriving the orders of stress singularity of interfacial cracks. The crack-tip elements in anisotropic materials are formulated by employing Lekhnitskii's stress functions and the variational principles of a hybrid functional. An iterative scheme for determining the closure size of a partially closed crack is proposed. Solutions for the orders of stress singularity of interfacial cracks in graphite-epoxy composites with different lamination variables and crack surface conditions agree well with the reference solutions. For the problem of an interfacial crack between two dissimilar anisotropic half spaces, finite element solutions are found very close to the exact solutions. Effects of element size, aspect ratio, and eigenfunction truncation of the crack-tip elements have been studied. Solutions for several delamination problems of practical interest are also presented by using hybrid crack-tip elements. Results of this study show that the Wiener-Hopf technique is a suitable method for investigating the dynamic behavior of interfacial cracks and that the hybrid crack-tip elements provide efficient and accurate numerical methods for studying delamination problems of composites.","Made available in DSpace on 2014-12-16T19:12:28Z (GMT). No. of bitstreams: 1 8302916.pdf: 3975945 bytes, checksum: 483a0fb69e6037d169aac14cf28bc4d8 (MD5) Previous issue date: 1982","Embargo set by: Seth Robbins for item 71836 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","184 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982."]},{"key":"dc:title","label":"Title","values":["Dynamic Analysis of Interfacial Cracks in Composite Laminates"]}]}],"canonical_facts":{"dc:creator":["Kuo, an-Yu"],"dc:date":["2014-12-16T19:12:28Z","10000-01-01","1982"],"dc:description":["The interfacial crack in composite laminates has been of great interest as composite materials are widely used today. In this paper, the order of dynamic stress singularity of interfacial cracks is derived, and a hybrid finite element method is successfully developed for this problem. Both the cases of open and closed cracks are considered. An integral transform, the Wiener-Hopf technique, and an asymptotic theory have been used for deriving the orders of stress singularity of interfacial cracks. The crack-tip elements in anisotropic materials are formulated by employing Lekhnitskii's stress functions and the variational principles of a hybrid functional. An iterative scheme for determining the closure size of a partially closed crack is proposed. Solutions for the orders of stress singularity of interfacial cracks in graphite-epoxy composites with different lamination variables and crack surface conditions agree well with the reference solutions. For the problem of an interfacial crack between two dissimilar anisotropic half spaces, finite element solutions are found very close to the exact solutions. Effects of element size, aspect ratio, and eigenfunction truncation of the crack-tip elements have been studied. Solutions for several delamination problems of practical interest are also presented by using hybrid crack-tip elements. Results of this study show that the Wiener-Hopf technique is a suitable method for investigating the dynamic behavior of interfacial cracks and that the hybrid crack-tip elements provide efficient and accurate numerical methods for studying delamination problems of composites.","Made available in DSpace on 2014-12-16T19:12:28Z (GMT). No. of bitstreams: 1 8302916.pdf: 3975945 bytes, checksum: 483a0fb69e6037d169aac14cf28bc4d8 (MD5) Previous issue date: 1982","Embargo set by: Seth Robbins for item 71836 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","184 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982."],"dc:identifier":["http://hdl.handle.net/2142/71670","(UMI)AAI8302916"],"dc:subject":["Applied Mechanics"],"dc:title":["Dynamic Analysis of Interfacial Cracks in Composite Laminates"],"dc:type":["text"],"thesis:degree_discipline":["Theoretical and Applied Mechanics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:05Z"}