SCF of Welded Thick-Walled Tubular Dragline Joints by Effective Notch Stress Method

In Australia, draglines are used extensively in the coal mining industry. The tubular booms of the dragline are susceptible to fatigue cracking due to the large number of cycles they are subjected to during operation. Fatigue cracks may occur at either weld toe or weld root of the dragline joints. This paper acts as the first attempt to use the effective notch stress (ENS) method to determine the notch stress factors (NSFs) of the dragline joints. Only simplified 2D finite element analysis (FEA) was carried out at this stage. It was found that the NSF at the weld toe is higher than the NSF at the weld root for LC(I). For LC(II), the NSF at the weld root is in general higher than the NSF at the weld toe. The NSF results obtained are also used to compare with those obtained by using ENS method in the literature.