Abstract:
Titanium alloy is a common material for deep-sea large manned carrier platform, and its fatigue properties of welded parts cannot be ignored. In this study, the butt welding and load bearing cruciform welding are carried out on the domestic TA31 titanium alloy, and the fatigue strength of the joints are evaluated by the hot spot stress approach. The test data are calculated by the method recommended by the International Institute of Welding (IIW). The
S-N curves of the nominal stress and hot spot stress are obtained and compared. The influence of plate thickness on the fatigue properties of the welded joints is analyzed by the notch stress approach, and the formula of plate thickness correction is obtained. These results can provide references for fatigue evaluation and anti-fatigue design of titanium alloy structures.