Stress Concentration Factor and Influencing Factor of Pressure Resistance Welding Joint of Zirconium Alloy Tube-End Plug

Zirconium alloy tube-end plugstructure pressure resistance welding joint formingmodel and stress concentration factor calculation model were established by Abaqus finite element analysis software. The weliding model was verified by comparing with the extruded metal height obtained by thermal simulation test. The effects of transition angle of internal extruded metal, end plug displacement and cladding tube inner wall chamfer on stress concentration factor of joint were analyzed. The results show that the relative error of the simulated internal extruded metal height and test results was 9.58%, and that of the external extruded metal height was 6.65%, verifing the accuracy of the welding model. With the increase of the transition angle of internal extruded metal, the stress concentration factor decreased first, then increased when the transition angle increased to 60°, and decreased when the angle was greater than 120°. With the increase of end plug displacement, the transition angle of internal extruded metal decreased, the stress concentration factor increased, and the length of the fusion line increased. Comparing with those of the joint without end plug, When the cladding tube inner wall chamfer depth was less than 0.50 mm, the stress concentration factor decreased, and the maximum reduction was 16.00%；when depth was more than 0.50 mm, the stress concentration factor increased, and the maximum increase was 91.49%.