Crack problems in thin-layered structures

Thin-layered structures are used in a variety of applications today. Prevention of failure of these structures is important by identify the integrity or strength of these structures. The thickness of the crack residing layer, the distance from crack to the layers interface and elastic modulus mismat...

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Bibliographic Details
Main Author: Lai, Alvin Junqi
Other Authors: Xiao Zhongmin
Format: Final Year Project (FYP)
Language:English
Published: 2009
Subjects:
Online Access:http://hdl.handle.net/10356/16166
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author Lai, Alvin Junqi
author2 Xiao Zhongmin
author_facet Xiao Zhongmin
Lai, Alvin Junqi
author_sort Lai, Alvin Junqi
collection NTU
description Thin-layered structures are used in a variety of applications today. Prevention of failure of these structures is important by identify the integrity or strength of these structures. The thickness of the crack residing layer, the distance from crack to the layers interface and elastic modulus mismatch all play an important role in the failure of these structures due to subinterface cracks. The investigations made in this report via finite element analysis software ANSYS suggested that Mode I stress intensity factor at crack tip for the five cases in study (centre and edge cracks in bi-layered structures, centre and edge cracks in tri-layered structures and collinear cracks in tri-layered structures) were affected by elastic modulus mismatch, crack-interface distance and also thickness of the crack-residing layer. Due to the difference in modeling, the results obtained differed from literature in bi-layered structure slightly but they conform to general trends available in literature. The tri-layered structure models presented a few unusual trends for some configurations but most of the results obtained followed general trend surveyed in literature. The investigations showed significant influences on crack stress intensity factor by the three factors above. The collinear cracks study suggested stress intensity factors are affected by the combined interactions between the two cracks and the three factors above.
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spelling ntu-10356/161662023-03-04T18:16:21Z Crack problems in thin-layered structures Lai, Alvin Junqi Xiao Zhongmin School of Mechanical and Aerospace Engineering DRNTU::Engineering::Mechanical engineering::Mechanics and dynamics Thin-layered structures are used in a variety of applications today. Prevention of failure of these structures is important by identify the integrity or strength of these structures. The thickness of the crack residing layer, the distance from crack to the layers interface and elastic modulus mismatch all play an important role in the failure of these structures due to subinterface cracks. The investigations made in this report via finite element analysis software ANSYS suggested that Mode I stress intensity factor at crack tip for the five cases in study (centre and edge cracks in bi-layered structures, centre and edge cracks in tri-layered structures and collinear cracks in tri-layered structures) were affected by elastic modulus mismatch, crack-interface distance and also thickness of the crack-residing layer. Due to the difference in modeling, the results obtained differed from literature in bi-layered structure slightly but they conform to general trends available in literature. The tri-layered structure models presented a few unusual trends for some configurations but most of the results obtained followed general trend surveyed in literature. The investigations showed significant influences on crack stress intensity factor by the three factors above. The collinear cracks study suggested stress intensity factors are affected by the combined interactions between the two cracks and the three factors above. Bachelor of Engineering 2009-05-21T09:22:45Z 2009-05-21T09:22:45Z 2009 2009 Final Year Project (FYP) http://hdl.handle.net/10356/16166 en Nanyang Technological University 86 p. application/pdf
spellingShingle DRNTU::Engineering::Mechanical engineering::Mechanics and dynamics
Lai, Alvin Junqi
Crack problems in thin-layered structures
title Crack problems in thin-layered structures
title_full Crack problems in thin-layered structures
title_fullStr Crack problems in thin-layered structures
title_full_unstemmed Crack problems in thin-layered structures
title_short Crack problems in thin-layered structures
title_sort crack problems in thin layered structures
topic DRNTU::Engineering::Mechanical engineering::Mechanics and dynamics
url http://hdl.handle.net/10356/16166
work_keys_str_mv AT laialvinjunqi crackproblemsinthinlayeredstructures