材料期刊网

Q345D high-quality low-carbon steel has been extensively employed in structures with stringent weld-ing quality requirements.A multi-objective optimization of welding stress and deformation was presented to design reasonable values of gas metal arc welding parameters and sequences of Q345D T-joints.The optimized factors included continuous variables (welding current (I), welding voltage (U) and welding speed (v)) and discrete variables (welding sequence (S) and welding direc-tion (D)).The concepts of the pointer and stack in Visual Basic (VB) and the interpolation method were introduced to optimize the variables.The optimization obj ectives included the different combina-tions of the angular distortion and transverse welding stress along the transverse and longitudinal dis-tributions.Based on the design of experiments (DOE) and the polynomial regression (PR) model, the finite element (FE) results of the T-joint were used to establish the mathematical models.The Pareto front and the compromise solutions were obtained by using a multi-objective particle swarm optimization (MOPSO) algorithm.The optimal results were validated by the corresponding results of the FE method, and the error between the FE results and the two-objective results as well as that be-tween the FE results and the three-objective optimization results were less than 17.2% and 21.5%, respectively.The influence and setting regularity of different factors were discussed according to the compromise solutions.