Research on the influence of welding defects on the fatigue life of welded joints and evaluation methods
LI Xiaofeng
ZHENG Yuhan
ZHANG Dailin
ZHANG Qiang
WANG Shuai
Abstract：[Objective]Welding defects are the key factors which affect the welding quality and structural property.In this research,the influence and evaluation method on the fatigue life of welded joints with welding defects,which was Q450NQR1 high strength weathering steel,were discussed through tests and numerical simulation.[Methods]Firstly,cross joint and butt joint specimens with different defects were prepared,and the defects of the specimens were quantitatively analyzed by ultrasonic detection method in order to ensure the effectiveness of the test specimens.Secondly,fatigue tests were carried out.The influence regularity of the anti-fatigue performance of cross welded joints with different types of defects was analyzed based on the S-N curve of BS 7608:2014 standard.Finally,based on the tests,an equivalent modeling method for joints with different welding defects was proposed.[Results]The results show that the influence degree of different types of defects on the fatigue life of cross welded joints is as follows:undercut defect>misalignment defect>porosity defect,and the levels of anti-fatigue are F,E and D.The equivalent initial crack values of different defects were obtained by using the equivalent modeling method of welding defects.And the fitting results of different defect sizes and equivalent initial crack sizes were obtained by least square method.The research results can provide references for the fatigue life evaluation of steel welded structures with defects.
Keywords：Q450NQR1 steelWelded jointInitial defectFatigue testEquivalent crack
Publication Date：2026-05-31
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：9( 66-74 )