Welded joints of Q355 structural steel are the weak links in the deflagration accident of large tanks at ultra-high voltage

and the prediction of their failure behaviors can effectively improve the safety of the tanks in service. In order to construct a reasonable failure model of welded joints

different tensile tests are designed for the weld zone

heat-affected zone and base material zone of the welded joints

and the stress triaxiality term

strain rate term and the modified temperature term parameter that better responds to the temperature softening effect are fitted to obtain the failure model of J-C. At the same time

the parameters of the failure model of the three zones are compared

and the failure model is validated through numerical simulation based on the constructed failure model. The results show that the complex stress state and strain rate have more obvious negative effects on the ductility of the heat-affected zone

the temperature has more obvious softening effects on the heat-affected zone and the base material zone

and the numerical simulation results are in good agreement with the test results.