Research on forming process parameters optimization of TWB for automobile cover panel

Aiming at the problem that the forming margin of the TWB automotive cover panel was insufficient and the welding area was easy to crack, the front door inner panel of a certain model was used as the research object, and the method of combining the test method and finite element analysis was adopted, and the main process parameters causing the cracking on the welding seam area of the front door inner panel were quickly screened out based on the orthogonal test, and the influence of the main process parameters on the formability of the front door inner panel was analyzed. Based on the evaluation of the maximum thinning rate of the welding seam area, the effects of the blank holder force B.H.F., the friction coefficient μ, the height of the first piercing cutter H1, the height of the second piercing cutter H2, and the width of the thinner sheet W on the forming quality of the front door inner panel were studied in turn. Using the analysis of variance and range, the primary and secondary order of the influence of each process parameter on the maximum thinning rate of the welding seam area was obtained, and the value of the process parameters were: B.H.F.= 1 000 kN, μ = 0.13, W = 1 044 mm, H2=11 mm, H1=10 mm. The forming simulation of the front door inner panel was carried out by the optimal combination of process parameters, the die tryout verification was carried out on this basis, and the parts with good forming quality and high margin were obtained, the maximum thinning rate of the weld area was 19.1%, which met the quality judgment standards.