Fracture behavior of a structure having a crack in the middle of a weld is influenced by the mechanical properties of the welded joint constituents (weld metal, base metal, heat-affected-zone) and their geometry. Therefore, defect assessment procedures have been developed in order to take into account all those affecting parameters. One of the key point for all those defect assessment procedures is to have limit load solutions of the mismatch structure. Such limit load solutions have been obtained by using 3D finite element solutions for different configurations such as plate with surface crack in tension or pressure vessel with axial external surface crack exposed to internal pressure, since those limit load have been obtained for non-hardening material exponent.