The Research of Forming Process Parameters Influence on the Square Cup of TWBs’ Weld-Line Movement

The forming process of the square cup of TWBs is studied through the numerical simulation by Dynaform, and combined with orthogonal test, analyzed the thickness ratio, strength ratio, weld-line position, total blank-holder force, the thinner side’s blank-holder rate and the friction coefficient’s relations with the square cup of TWBs’ weld-line movement during the stamping process, and using the BP neural network toolbox model to forecast the weld-line movement in the process of forming. Studies show that regardless of the thickness ratio impact on the bottom of the square cup or on the flange, weld-line movements are at the maximum, the strength ratio is the second. The smaller proportion of the thinner side of the base material, the lower weld-line movement is. Selecting the suitable thinner side and thicker side’s blank-holder, and the reasonable lubrication conditions can control the value of the weld-line movement.