Study on KIC of TC4-DT titanium alloy electron beam welding

Abstract

With the development and application of TC4-DT titanium alloy and electron beam welding, the research on fatigue crack growth of its joints is very important in engineering. In this paper, the relevant fracture mechanics and crack growth theory are proposed for the fatigue crack growth of TC4-DT titanium alloy electron beam welded joints, and the experimental and finite element method simulation crack growth research is carried out. The results show that: during the fatigue crack test, with the continuous increase of the cycle period, the crack growth rate in different regions increases significantly, among which the growth rate of the weld zone is higher, and the crack propagation path in the weld zone is almost completely along the weld zone. The direction of the axis of symmetry of the center of the crack propagates linearly, and the crack propagation in the base metal area basically expands along the straight line but slightly deviates to the upper base metal area. By calculating the stress intensity factor of different preset crack lengths through simulation, it is found that within the allowable error range, with the increase of the prefabricated crack length, the stress intensity factor k1 of the specimen increases gradually.