A boundary element analysis of fatigue crack growth for welded connections under bending

Transverse fillet welded joints and circular hollow section (CHS)-to-plate welded connections were analyzed to obtain crack growth life under bending. Based on a 3D boundary element model, an initial semi-elliptical surface crack was embedded at the weld toe. Thereafter, crack propagation was performed with Paris’ law and strain energy density criterion. This method discards the assumption of constant aspect ratio of crack shape during propagation stage. Numerical results were compared with the experimental results in the literature. It is found that numerical analysis is reliable and the boundary element method is suitable for estimating the fatigue crack growth life.

► Crack growth was investigated for transverse fillet welded joints and CHS-to-plate welded connections by BEM.
► The 3D boundary element model discards the assumption of constant aspect ratio of crack shape during propagation stage.
► The numerical results were verified with comparison to the experimental results in the literature.