Research On Tailor-welded Blanks Automobile Panels Surface Optimization And Forming Quality Control Based On The FEA

Tailor-Welded Blanks(TWBs) refers to two or more pieces of sheets welding together before forming. These sheets can meet the performance requirements of different position parts which have different thickness, material properties and surface coatings. With the peoples’ attention of automobile energy conservation, environmental protection and driving safety, automobile makers need constant innovation process to lower the body weight, and TWBs provide a good solution for the above problems. But owing to exist welding line and heat affected zone and the differences in the mechanical properties and thickness of the parent metal on the both sides of welding line, Tailor-Welded Blanks cause rupture, wrinkle, springback and welding line movement, the forming performance decline, and even forming difficulties.This paper applies the finite element analysis software DYNAFORM to simulate and research the typical U-shaped part of laser TWBs. The universal laws of welding line movement and springback are researched. It is founded that the welding line moves towards thicker sheets and higher strength with the same blank holder force, the springback amount decreases with the increment of blank holder force, and the springback amount on the either side of TWBs is larger than that on the corresponding flat blank. The numerical simulation and experiment research is done based on the forming, springback and springback compensation of TWBs U-shaped part. It is founded that the springback of U-shaped part can be eliminated basically after two times of the springback compensation iteration, and the experiment is done to confirm the accuracy of the finite element numerical simulation results.Researched on the drawing and springback in the inner door panel of the laser TWBs, it is forecasted that there will be some defects in forming and it is optimized by setting the draw bead and adjusting the blank holder force. Under the circumstances of satisfied forming effect, it is analyzed to process springback for inner door panel. The springback compensation integrally is done for die based on springback results. The numerical simulation of forming and springback is carried again by using the die after compensating. Finally the molded surface of component after springback is identical with that of standard component, and it can conquer the field of springback compensation. At the end, high-quality inner door panel automobile panel can be received by trimming, punching.