Fatigue performance assessment of circular hollow section tube-to- plate welded joints based on effective notch stress approach

摘要

The circular hollow section (CHS) tube-to-plate welded joints are extensively used in steel bridges (see Fig.l),therefore it is important to evaluate their fatigue performance. While,multiple current Fatigue Standards provide notable different classifications for this type of connections. Also,the fatigue test data is relatively limited. In 1975,Zirn[l] carried out a series of fatigue experiments on the CHS tube-to-plate welded connections with several combinations of weld types and geometry chamfer shapes. Based on Zirn's dataset,Baptista et al. [2] recently studied the connection type effect on fatigue performance of the joint with 24 groups of fatigue tests,together with effective notch stress analyses. However,in the analyses of Baptista et al. [2],the effective notch stress approach (ENSA) gave relatively poor performance when evaluating the fatigue life (or FAT class). Moreover,some contradictions about the initial crack location were found when compared to [1]. Hence,in order to improve the previous researches (i.e. [1] and [2]) several configurations of weld types and geometric details were investigated in this work by means of the ENSA,focusing the attention on the effects of the geometry on notch stress concentration factors (SCFs).