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Indexed by:会议论文

Date of Publication:2009-06-21

Included Journals:EI、Scopus

Page Number:246-252

Abstract:Fatigue design rules for offshore structures are based on research work of relatively small welded joints for financial reasons and for ease of experimentation. However, extrapolation of the results to bigger and thicker welded joints may not be safe, especially for extra thick joints that are even up to 100 mm thick and more. In this paper, the hot-spot stress analysis procedure as well as the thickness effect correction method, recommended in the current fatigue design rules, was examined for extra thick welded joints by using Finite Element (FE) calculation. Both solid and shell elements were used in the hot-spot stress analysis to investigate the influence zone of notch stress concentration due to the weld toe, appropriate element size and positions of the reference points for the stress extrapolation. The thickness effect was studied based on fracture mechanics theory. The stress intensity factor (SIF) of a surface crack at the weld toe, obtained from FE analysis, was used to calculate the fatigue life of welded joints with different plate thicknesses. The results show that the proposed hot-spot stress analysis method is applicable to the fatigue assessment of extra thick welded joints. Copyright ? 2009 by The International Society of Offshore and Polar Engineers (ISOPE).