Stress Analysis and Fatigue of Weldments

Fatigue life estimation for welded structures requires knowledge of the stress field at the critical locations. The proposed method allows for the determination of the stress distribution in the weld toe region using a shell finite element model. The region of interst must be meshed such that the gradient of the through-thickness stress is captured. The stress data obtained via the shell finite element model is then modified via stress concentration factors to obtain peak stress values and estimate the fatigue life of a component. The stress distribution obtained using this method may also be used for fatigue crack growth analyses. One type of welded joint was used to validate the proposed method: a Desmoines T-joint welded connection. The reference stresses for these geometries were obtained using finely-meshed three-dimensional finite-element models. The shell finite element model was found to be in good agreement with the results from the threedimensional finite-element models.