Fatigue reliability assessment of welded joints in steel bridges considering multiple effects

Xiaowei Ye, Dabao Fu, Yiqing Ni, Kaiyuen Wong, Shaofei Jiang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

3 Citations (Scopus)

Abstract

A novel method for fatigue reliability assessment of welded joints in steel bridges is proposed by considering multiple effects in terms of the stress concentration phenomenon at the welded joint as well as the reduction of the effective cross-sectional area and the degradation of the fatigue behavior due to steel corrosion. The proposed method is applied to assess the fatigue reliability of a typical welded joint in the instrumented Tsing Ma Bridge using the long-term strain monitoring data. By exploring the stochastic characteristics of the hot spot stress range, the reduction model of the cross-sectional area, and the fatigue behavior degradation function of the welded joint, a fatigue reliability model considering multiple effects is developed in the framework of a continuous probabilistic formulation of Miner's damage cumulative rule. A standard daily stress spectrum accounting for highway traffic, railway traffic, and typhoon effects is derived by statistically analyzing the long-term strain monitoring data. A multi-modal Probability Density Function (PDF) of the standard daily stress spectrum is obtained by use of the method of finite mixture distributions in conjunction with a Genetic Algorithm-based (GA-based) mixture parameter estimation approach. A comparative study is conducted to investigate the effects of stress concentration and steel corrosion (i.e., reduction of the effective cross-sectional area and degradation of the fatigue behavior) on the failure probability and reliability index versus the predicted fatigue life of the welded joint. The results show that the fatigue reliability of the welded joint is significantly influenced by the effects of stress concentration and steel corrosion.
Original languageEnglish
Pages (from-to)89-99
Number of pages11
JournalTumu Gongcheng Xuebao/China Civil Engineering Journal
Volume46
Issue number10
Publication statusPublished - 1 Oct 2013

Keywords

  • Fatigue reliability
  • Health monitoring of bridges
  • Steel bridges
  • Steel corrosion
  • Stress concentration effect

ASJC Scopus subject areas

  • Architecture
  • Civil and Structural Engineering
  • Building and Construction
  • Arts and Humanities (miscellaneous)

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