Study On Flexible Forming Of Tailor-welded Blanks Using Plasma Arc

TWB (Tailor-welded Blanks) are welded into a whole board with two or more sheet metal of different thickness or material properties; the purpose is to make full use of material properties without waste. Flexible forming of TWB using plasma arc is a non-mold forming technology of TWB. The paper proposes the concept of flexible bend forming of TWB using plasma arc, after a full analysis on the research status at home and abroad of TWB forming technology and flexible forming method, the advantages and disadvantages of all the forming methods are also studied.The simulation calculation was carried out using ANSYS combined with APDL (ANSYS Parametric Design Language) for the process of TWB bend forming using plasma arc to study the bend forming mechanism of different thickness TWB. Firstly, the paper established the finite element model of different thickness TWB and divided the geometric model into non-uniform finite element mesh combining the structural characteristics of TWB. the plasma arc heating zone and heat-affected zone were also considered. Secondly, a thermal analysis unit solid70was used during the temperature field simulation, and the unit would be converted to structure analysis unit solid45for stress-strain field simulation. Three parameters conditions were used during the finite element simulation, such as constant speed and power heat source, variable speed and constant power heat source, constant speed and variable power heat source. Finally, the analysis results of temperature field and stress-strain field simulation shows that there appeared local uneven warping in the TWB in the case of constant speed and power, while the simulation results of variable speed and constant power, constant speed and variable power heat source shows good bend forming consistency.To verify the correctness of the finite element simulation results, the equal thickness TWB and different thickness TWB were studied respectively under the same parameters with finite element analysis process, the results of the three different experiment parameters have good agreement with the finite element simulation results, it shows that ANSYS can be used to simulate flexible forming of TWB using plasma arc. According to the inhomogeneous deformation of local warping during TWB forming process, the paper did some metallographic and hardness research for TWB weld scanned and non-scanned by plasma arc, in order to study the forming mechanism and bending process from the microscopic point of view.The bend forming of TWB using plasma arc has the advantages of short product development cycle and low-cost, at the same time, has a lower equipment costs, and the operation is simpler than laser bend forming technology, higher accuracy and easier to control than the line heating forming.