Research On Incremental Forming Process And Springback Control Of Laser Tailor-welded

Owing to the advantages of high flexibility, low-cost, low forming force and high form ability, incremental forming becomes one of the new sheet metal forming methods in recent years, which is rarely applied to the research of the forming of laser tailor-welded plate. Laser tailor-welded plate has been widely used everywhere because of the ways it has paved for the automotive lightweight, energy conservation and emissions reduction, manufacturing cost reduction, improvement of vehicle safety, etc.With the increasing mature of laser tailor-welded plate and incremental forming technology, putting the incremental forming technology into the laser tailor-welded sheet has becomes especially vital to the area of engineering.Studies found that both domestic and foreign using the incremental forming technology into the research laser tailor-welded sheet is not mature enough, there are many issues to be resolved. Common defects in sheet metal of incremental forming process are: parts over the forming limit, surface quality defects and the low accuracy.Therefore, this article mainly discusses the forming limit and forming precision of incremental forming in the laser tailor-welded plate.First, this paper introduces the present situation and development of sheet metal incremental forming in the world and the characteristic of the laser tailor-welded plate,as well as a method of weld model in the numerical simulation. Then, with the variable angle ellipse part as the research object, a tailor-welded plate finite element model was built by using FEM in view of the problem of forming limit. The impact on forming properties of laser TWBS is researched by means of orthogonal experiment, what the main process parameters include tool diameter, tool depth, welding seam position and plate thickness. Finally, for the problem of springback during forming cone, researching the rebound problem of laser tailor-welded plate incremental forming by the numerical simulation; verifying the validity of the finite element model through the experiment;using the method of neural network to establish the rebound prediction model.The result shows that:Incremental forming performance: Weld position is the main factors for sheet metal forming limit, followed by combination of thickness, tool diameter and tool depth; Weld perpendicular to the principal strain can ensure uniform deformation; Maximizing tooldepth not only helps to improve the forming efficiency of laser tailor welded plate, but also can improve the formed limit effectively on the premise of ensuring the accuracy of the machining parts and meeting the shaping ability of the equipment, to maximize tool depth not only help to improve the forming efficiency of laser tailor welded blanks, but also can improve the formed limit effectively.Incremental forming precision: Forming height is the biggest problems of the rebound of plate, followed by tool depth, half-apex Angle and tool diameter. The higher forming height, the more plastic deformation of sheet metal, the smaller rebound. BP neural network prediction model can be used to predict the rebound of the formed parts under the condition of different process parameters.Through studying forming performance and rebound of the incremental forming process parameters, combining the BP neural network accurately forecast for the rebound in the laser welding plate incremental forming, to predict the springback under different process parameters, and thus to guide the selection of process parameters, to achieve the purpose of control the springback.