Mechanics of dislocations in multilayered materials
This thesis reports an investigation into the mechanics of anisotropic multilayered materials embedded with dislocations. An image technique is developed for solving the problems of infinite bilayers, film-substrates and general N-layer composites. The key contributions are: (1) the development of a...
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sg-ntu-dr.10356-52842023-03-11T17:43:25Z Mechanics of dislocations in multilayered materials Wang, Huyi Wu Mao See School of Mechanical and Aerospace Engineering DRNTU::Engineering::Materials::Metallic materials This thesis reports an investigation into the mechanics of anisotropic multilayered materials embedded with dislocations. An image technique is developed for solving the problems of infinite bilayers, film-substrates and general N-layer composites. The key contributions are: (1) the development of an image decomposition scheme which is instrumental to the accuracy of the complete solution, and (2) the elimination of singularities from the governing integral equations using certain H and I transforms. Numerical investigations reveal that many factors, e.g., elastic anisotropy and layer inhomogeneity, will significantly influence the image forces acting on the dislocation. Furthermore, a single-ended discrete dislocation pileup model is developed and used to show that the shear strength dependence on layer thickness obeys the Hall-Petch relation quite well for sufficiently thick layers while image forces result in a deviation of the relation for very thin layers. The numerical predictions are in good agreement with a comprehensive set of experimental data for metallic multilayer systems. DOCTOR OF PHILOSOPHY (MPE) 2008-09-17T10:47:03Z 2008-09-17T10:47:03Z 2007 2007 Thesis Wang, H. (2007). Mechanics of dislocations in multilayered materials. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/5284 10.32657/10356/5284 Nanyang Technological University application/pdf |
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DRNTU::Engineering::Materials::Metallic materials Wang, Huyi Mechanics of dislocations in multilayered materials |
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This thesis reports an investigation into the mechanics of anisotropic multilayered materials embedded with dislocations. An image technique is developed for solving the problems of infinite bilayers, film-substrates and general N-layer composites. The key contributions are: (1) the development of an image decomposition scheme which is instrumental to the accuracy of the complete solution, and (2) the elimination of singularities from the governing integral equations using certain H and I transforms. Numerical investigations reveal that many factors, e.g., elastic anisotropy and layer inhomogeneity, will significantly influence the image forces acting on the dislocation. Furthermore, a single-ended discrete dislocation pileup model is developed and used to show that the shear strength dependence on layer thickness obeys the Hall-Petch relation quite well for sufficiently thick layers while image forces result in a deviation of the relation for very thin layers. The numerical predictions are in good agreement with a comprehensive set of experimental data for metallic multilayer systems. |
author2 |
Wu Mao See |
author_facet |
Wu Mao See Wang, Huyi |
format |
Theses and Dissertations |
author |
Wang, Huyi |
author_sort |
Wang, Huyi |
title |
Mechanics of dislocations in multilayered materials |
title_short |
Mechanics of dislocations in multilayered materials |
title_full |
Mechanics of dislocations in multilayered materials |
title_fullStr |
Mechanics of dislocations in multilayered materials |
title_full_unstemmed |
Mechanics of dislocations in multilayered materials |
title_sort |
mechanics of dislocations in multilayered materials |
publishDate |
2008 |
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https://hdl.handle.net/10356/5284 |
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1761781914106068992 |