Experimental Study And Numerical Simulation On Residual Welding Stress Relaxation

In this paper, the welding residual stress and the relaxation under static load are discussed by experimental research and numerical simulation. In order to understand relaxation of welding residual stresses caused by external static and dynamic loads, tests investigating relaxation of welding residual stresses caused by external static and dynamic loads in the Q345 plate welded specimens were carried out. The thermal-structural sequential coupling method was used to simulate the residual stresses of welded specimens. Based on the elastic-plastic finite element method, the relaxation behavior of welded specimens under static and cyclic loads was simulated respectively. The test of the residual stress relaxation by welding shows that the relaxation of the welding residual stress is caused when the external load is applied to the welded specimen in static and dynamic form. The residual stress relaxation condition is that the welding residual stress and the external load cause the stress to superimpose more than the material yield strength. Under the action of equal amplitude cyclic stress, the relaxation of welding residual stress occurs mainly at the end of the first stress cycle.