Analysis of cracked tubular joints using coupled finite and boundary element methods

A coupling scheme of finite elements to boundary elements is suggested for solving any general cracked problems. The relationship between nodal displacements and tractions on the interface from finite element equations can be introduced into boundary integral equation as a natural boundary condition. The efficiency of the method is demonstrated by modellling and analyzing cracked T-tubular welded joints with an initial semi-elliptical surface crack at the saddle point. The boundary elements are used for stress intensity factor computations in the domain with crack and high stress gradient, and finite elements are used in other parts of the structure with low stress gradients. Numerical results are given to compare the accuracy and efficiency of the method.