Behaviour and design of high-performance steel welded I-section structural components

High-performance steels, including stainless steels and high strength steels, have been gaining increasing attention in civil engineering, owing to their appealing sustainable and mechanical advantages. The present thesis is focusing on the behaviour and design of high-performance steel welded I-sec...

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Main Author: Sun, Yao
Other Authors: Zhao Ou
Format: Thesis-Doctor of Philosophy
Language:English
Published: Nanyang Technological University 2021
Subjects:
Online Access:https://hdl.handle.net/10356/149425
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author Sun, Yao
author2 Zhao Ou
author_facet Zhao Ou
Sun, Yao
author_sort Sun, Yao
collection NTU
description High-performance steels, including stainless steels and high strength steels, have been gaining increasing attention in civil engineering, owing to their appealing sustainable and mechanical advantages. The present thesis is focusing on the behaviour and design of high-performance steel welded I-section structural components. A comprehensive testing programme was firstly conducted, which adopted twelve welded I-sections made of two types of high-performance steel (grade EN 1.4420 high-chromium stainless steel and S690 high strength steel). Material testing was carried out to derive the material stress–strain responses of the two adopted high-performance steel grades, and membrane residual stress measurements were performed to determine the membrane residual stress distributions and amplitudes in the studied high-performance steel welded I-sections. At the cross-sectional level, a total of 24 axially loaded stub column tests, 20 in-pane four-point bending tests, and 10 eccentrically loaded stub column tests were conducted to investigate the cross-section resistances and local stability of high-performance steel welded I-sections. At the member level, 40 column tests and 10 beam-column tests were performed to study the load-carrying capacities and member instability of high-performance steel welded I-sections. The testing programme was supplemented by a numerical modelling programme, where finite element models were firstly developed and validated against the test results and then employed to perform a series of numerical parametric studies to generate additional numerical data over a wide range of cross-section dimensions, member lengths and loading combinations. The obtained test and numerical results were used to evaluate (i) the applicability of the current design codes for normal stainless steel members to the new high-chromium stainless steel welded I-section members and (ii) the accuracy of the existing relevant design codes for S690 high strength steel welded I-section members. The evaluation results generally indicated that the current design codes result in inaccurate resistance predictions, mainly owing to the lack of due consideration of the specific material characteristics of the two types of high-performance steel. New design methods have also been proposed, which were shown to provide substantially improved design accuracy and consistency over the existing design standards. The reliability of the proposed design methods has been confirmed by means of statistical analyses, demonstrating their suitability for incorporation into future revisions of international design codes for stainless steel and high strength steel structures.
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spelling ntu-10356/1494252021-07-08T16:00:37Z Behaviour and design of high-performance steel welded I-section structural components Sun, Yao Zhao Ou School of Civil and Environmental Engineering ou.zhao@ntu.edu.sg Engineering::Civil engineering::Structures and design High-performance steels, including stainless steels and high strength steels, have been gaining increasing attention in civil engineering, owing to their appealing sustainable and mechanical advantages. The present thesis is focusing on the behaviour and design of high-performance steel welded I-section structural components. A comprehensive testing programme was firstly conducted, which adopted twelve welded I-sections made of two types of high-performance steel (grade EN 1.4420 high-chromium stainless steel and S690 high strength steel). Material testing was carried out to derive the material stress–strain responses of the two adopted high-performance steel grades, and membrane residual stress measurements were performed to determine the membrane residual stress distributions and amplitudes in the studied high-performance steel welded I-sections. At the cross-sectional level, a total of 24 axially loaded stub column tests, 20 in-pane four-point bending tests, and 10 eccentrically loaded stub column tests were conducted to investigate the cross-section resistances and local stability of high-performance steel welded I-sections. At the member level, 40 column tests and 10 beam-column tests were performed to study the load-carrying capacities and member instability of high-performance steel welded I-sections. The testing programme was supplemented by a numerical modelling programme, where finite element models were firstly developed and validated against the test results and then employed to perform a series of numerical parametric studies to generate additional numerical data over a wide range of cross-section dimensions, member lengths and loading combinations. The obtained test and numerical results were used to evaluate (i) the applicability of the current design codes for normal stainless steel members to the new high-chromium stainless steel welded I-section members and (ii) the accuracy of the existing relevant design codes for S690 high strength steel welded I-section members. The evaluation results generally indicated that the current design codes result in inaccurate resistance predictions, mainly owing to the lack of due consideration of the specific material characteristics of the two types of high-performance steel. New design methods have also been proposed, which were shown to provide substantially improved design accuracy and consistency over the existing design standards. The reliability of the proposed design methods has been confirmed by means of statistical analyses, demonstrating their suitability for incorporation into future revisions of international design codes for stainless steel and high strength steel structures. Doctor of Philosophy 2021-05-19T04:50:12Z 2021-05-19T04:50:12Z 2021 Thesis-Doctor of Philosophy Sun, Y. (2021). Behaviour and design of high-performance steel welded I-section structural components. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/149425 https://hdl.handle.net/10356/149425 10.32657/10356/149425 en This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0). application/pdf Nanyang Technological University
spellingShingle Engineering::Civil engineering::Structures and design
Sun, Yao
Behaviour and design of high-performance steel welded I-section structural components
title Behaviour and design of high-performance steel welded I-section structural components
title_full Behaviour and design of high-performance steel welded I-section structural components
title_fullStr Behaviour and design of high-performance steel welded I-section structural components
title_full_unstemmed Behaviour and design of high-performance steel welded I-section structural components
title_short Behaviour and design of high-performance steel welded I-section structural components
title_sort behaviour and design of high performance steel welded i section structural components
topic Engineering::Civil engineering::Structures and design
url https://hdl.handle.net/10356/149425
work_keys_str_mv AT sunyao behaviouranddesignofhighperformancesteelweldedisectionstructuralcomponents