Investigation of draw-trimming springback of laser tailor-welded blanks

Abstract

By the numerical simulation and experiments,the process analysis of draw-bending and draw-trimming of the tailor-welded blanks (TWBs) with the thickness ratio 1.2 mm/0.8 mm are made,in which the effect of the blank holder force (BHF), friction factor and die profile radius,etc.on the springback are mainly investigated.The TWBs' springhack angle in the corner of punch and die,the total springhack angle and the sidewall curvature are surveyed in draw-bending and draw-trimming.And the welded line movement,the stress distribution in TWBs forming and their interact relationship are analyzed.The TWBs' springback in draw-bending and draw-trimming are badly influenced by the BHF,friction factor,die profile radius etc.,in which the BHF is the key factor;there is an intimate relationship between TWBs' draw-bending springback/draw-trimming springhack and welded-line movement,by which it will be advantageous to reduce the TWBs' springback through controlling the welded-line movement.In comparison,the TWBs' draw-trimming springhack is smaller than the TWBs' draw-bending springback,so it is better to use draw-trimming process for controlling TWBs' springback and improving the shape precision of TWBs' forming.