Prediction And Control Of Welding Deformation Based On The Approach Of Heat Dissipation Enhancement

As the development of the mechanism turned to the trend of lightweight, thestructures with sheet metal have been widely used for the shipbuilding, vehiclemanufacturing and the aerospace industries. These materials can reduce the weightmeanwhile improve the load carrying capacity of the equipments. However, thestructure with the sheet metal has a significant problem of the welding deformation.Since the sheet metal has low stiffness and bad stability, it will cause the weldingdeformation for such material. This prevents the application of the sheet metalmaterial, so it will be an advantage that the problem is solved.The present study first focuses on the temperature field during the welding byusing the finite element analysis (FEA). The boundary condition is set to be theaverage coefficient of heat extraction. Based on the special mesh law and the usersubroutines of the DFLUX, the movable source of heat can be achieved, subsequentlythe temperature field of welding can be simulated. Then according to the thermoelastic-plastic theory of material, the stress field of sheet metal during welding can beobtained. With the results of these, the cause of the deformation is analyzed.Depended on the earlier researches of welding deformation control, the articleprovides a new technique based on the approach of strengthened heat extraction. Thenthe simulation of the strengthened heat extraction is conducted based on the FEA tools,and the temperature as well as the stress fields are both obtained. Compared with theclassic approach of welding, the principle of the welding deformation control by thenew approach is studied. Then Based on the parameter study, the optimized technicalparameters for the welding approach based on the strengthened heat extraction aredecided.Next the examination of the new approach is conducted. The result, which showsgreat reduction of the welding deformation, has proved the effect of the new approach.The comparison study between the simulation and the test is proceeding, from theerror analysis, the step-optimization is used to get the better technical parameters ofthe new approach. At last, the methods to avoid the errors for the operation of weldingare brought out.In this study, the new approach of welding based on the strengthened heatextraction is proved to be effective. From the analysis of simulation results and theexamination errors, the approach of bypass flow control is supported to be thesolution.