Issue 48

M. Tirenifi et alii, Frattura ed Integrità Strutturale, 48 (2019) 357-369; DOI: 10.3221/IGF-ESIS.48.34 365 Figure 11 : The location of the crack examined for 2D dimensions, a) the cruciform weld root, b) the butt weld root. 8-node biquadratic plane stress quadrilateral elements are used in 2D models as shown in Fig. 12. The total number of elements are 28861 and 23974 for cruciform and butt weld, respectively. Note that a 6-node quadratic plane stress triangle are used in the crack front and the element sizes in these models are about 0.125 mm around the crack front. K and G are computed based on the domain integral using 4 contours. Figure 12 : Mesh used for the FE simulations of cruciform weld and butt weld. N UMERICAL RESULTS AND DISCUSSION Weld toe he results of the numerical study for the cruciform and butt-welded joints, with equal attachment and main plate thickness B=5 mm, are plotted in Fig. 13. This figure presents the results of K factor and G against the crack length a , with parabolic curves. Increasing of a , increase the value of K and G. It can be seen that the effect of a is most important on the values of K and G. the effect of the a on the stress intensity factor and the energy realize rate for cruciform welded joint is similar to that for the butt welded joint. It can be seen that the welding profile has no effect on the parameters of the fracture mechanics. The values of the stress intensity factor and G for cruciform and butt-welded joint are almost similar. T