| Welding is one of the most common methods of joining engineering structures. Under cyclic loading, welds, particularly weld toes, are prone to fatigue cracking. This is because of their geometry, which act a stress concentrator, along with the often high residual stresses due to the welding process. Computational weld and fatigue analyses present great advantages for design engineers. An accurate analysis can help the designer predict and account for the fatigue lives of welded structures before beginning experimental testing, which can be costly and time consuming. Crack initiation is predicted using the strain-life method with the Ramberg-Osgood stress-strain constitutive model and crack growth is predicted using linear elastic fracture mechanics. Finite element models of a hole and a double-fillet weld joint are used to predict the stress concentrations at blunt notches and sharp notches and agree very well with analytic results. A single-edge crack specimen is cyclically loaded to predict stress intensity factors and fatigue crack propagation. These results also agree very well with analytic solutions. Finally, a welded gusset joint is analyzed, incorporating both welding residual stresses and in-service loading. |
