Model and mesh generation of partially overlapped circular hollow section k-joints for fatigue studies

In this study, a novel and consistent geometrical model and mesh generation technique is proposed for partially overlapped CHS K-joints with and without crack. For the mesh without crack, the geometrical model of welding details is developed both on the chord and brace sides by a new approach such t...

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Main Author: Nguyen, Thi Bich Ngoc
Other Authors: Chiew Sing Ping
Format: Thesis
Language:English
Published: 2010
Subjects:
Online Access:https://hdl.handle.net/10356/41764
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author Nguyen, Thi Bich Ngoc
author2 Chiew Sing Ping
author_facet Chiew Sing Ping
Nguyen, Thi Bich Ngoc
author_sort Nguyen, Thi Bich Ngoc
collection NTU
description In this study, a novel and consistent geometrical model and mesh generation technique is proposed for partially overlapped CHS K-joints with and without crack. For the mesh without crack, the geometrical model of welding details is developed both on the chord and brace sides by a new approach such that the cut off requirements by AWS (1996) and API (2000) can be satisfied. Welding parameters are verified and adjusted by the measurement of welding thickness on small and full scale specimens. Furthermore, a general algorithm is developed for the determination of the theoretical and actual intersection points between the braces and the chord, which is a distinctive feature of partially overlapped CHS K-joints. For the mesh with crack, a general model for the inclined crack surface and an unsymmetrical crack front are proposed. Based on the developed geometrical model, a new mesh modelling method is proposed for partially overlapped CHS K-joints. The mesh generator is constructed step-by-step, therefore it is able to produce several kinds of meshes such as surface meshes, solid meshes, meshes with or without welding and crack details. At each step, a particular mesh can be exported depending on the complexity of the particular fatigue problem under consideration. The application range of the mesh generator is extended for special cases of identical chord and braces dimensions as well as large overlapped percentage, which are not commonly covered by other commercial software packages. Most importantly, it is able to generate a solid mesh with welding details and surface crack of any length and locates at either sides of the joint intersection. In the experimental program, two full-scale partially overlapped CHS K-joints were tested under cyclic combined loads in order to gather more information about the fatigue performance of the joints, as well as to evaluate the surface crack model proposed. During the tests, the crack initiation and propagation were monitored.
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spelling ntu-10356/417642023-03-03T19:13:59Z Model and mesh generation of partially overlapped circular hollow section k-joints for fatigue studies Nguyen, Thi Bich Ngoc Chiew Sing Ping Lee Chi King Lie Seng Tjhen School of Civil and Environmental Engineering DRNTU::Engineering::Civil engineering::Structures and design In this study, a novel and consistent geometrical model and mesh generation technique is proposed for partially overlapped CHS K-joints with and without crack. For the mesh without crack, the geometrical model of welding details is developed both on the chord and brace sides by a new approach such that the cut off requirements by AWS (1996) and API (2000) can be satisfied. Welding parameters are verified and adjusted by the measurement of welding thickness on small and full scale specimens. Furthermore, a general algorithm is developed for the determination of the theoretical and actual intersection points between the braces and the chord, which is a distinctive feature of partially overlapped CHS K-joints. For the mesh with crack, a general model for the inclined crack surface and an unsymmetrical crack front are proposed. Based on the developed geometrical model, a new mesh modelling method is proposed for partially overlapped CHS K-joints. The mesh generator is constructed step-by-step, therefore it is able to produce several kinds of meshes such as surface meshes, solid meshes, meshes with or without welding and crack details. At each step, a particular mesh can be exported depending on the complexity of the particular fatigue problem under consideration. The application range of the mesh generator is extended for special cases of identical chord and braces dimensions as well as large overlapped percentage, which are not commonly covered by other commercial software packages. Most importantly, it is able to generate a solid mesh with welding details and surface crack of any length and locates at either sides of the joint intersection. In the experimental program, two full-scale partially overlapped CHS K-joints were tested under cyclic combined loads in order to gather more information about the fatigue performance of the joints, as well as to evaluate the surface crack model proposed. During the tests, the crack initiation and propagation were monitored. Doctor of Philosophy (CEE) 2010-08-11T07:25:50Z 2010-08-11T07:25:50Z 2008 2008 Thesis Nguyen, T. B. N. (2008). Model and mesh generation of partially overlapped circular hollow section k-joints for fatigue studies. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/41764 10.32657/10356/41764 en 241 p. application/pdf
spellingShingle DRNTU::Engineering::Civil engineering::Structures and design
Nguyen, Thi Bich Ngoc
Model and mesh generation of partially overlapped circular hollow section k-joints for fatigue studies
title Model and mesh generation of partially overlapped circular hollow section k-joints for fatigue studies
title_full Model and mesh generation of partially overlapped circular hollow section k-joints for fatigue studies
title_fullStr Model and mesh generation of partially overlapped circular hollow section k-joints for fatigue studies
title_full_unstemmed Model and mesh generation of partially overlapped circular hollow section k-joints for fatigue studies
title_short Model and mesh generation of partially overlapped circular hollow section k-joints for fatigue studies
title_sort model and mesh generation of partially overlapped circular hollow section k joints for fatigue studies
topic DRNTU::Engineering::Civil engineering::Structures and design
url https://hdl.handle.net/10356/41764
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