Koei Takena

Fatigue strengths of longitudinal fillet-welded joints - Influence of weld stop and start operations.

The purpose of this study is to make clear the influence of the weld surface irregularity induced by the weld stop-start operation on the fatigue strength of longitudinal fillet welded joint. The materials used are 500 MPa and 600 MPa class steels. Weldings are done by manual arc processes and weld stop-start operations are carried out as leaving or filling the crater. The specimen is a flat plate with 16 mm thick and 60 mm wide. After the weld surface irregularities are measured, the specimens are tested under axial cyclic loadings. Then, the fatigue crack initiation and propagation behavior is closely observed. The test results indicate that the weld stop-start operation as filling the crater is preferable with respect to the fatigue strength.