Weld Line Movement Control Method And Its Application On Inner Door Panel With Tailor-welded Blanks Structure

The tailor-welded blanks (TWB) are widely used in the automobile industry, forthe advantages such as low manufacturing cost, environmental protection and safetyimprovement, etc. The weld line movement is the main defect in the stamping processof the TWB. As there are great differences including thickness, mechanical propertiesand shape between the two sides of the TWB, which make the stress and strain verycomplex in the stamping process.So the weld line movement is very easily.Therefore, in order to control the weld line movement and improve theformability, it is very necessary to study the the stamping process of the tailor-weldblanks, the main work in this paper is concluded as follows.By the numerical simulation on the stamping of a TWB square-box part, based onthe mechanical model, the influence of parameters on the weld-line movement of theTWB is studied in this paper, including the thickness ratio, the shrength ration, thelocations of the weld-line, the drawbead restraining forces, the blank holder force andthe friction coefficient. The results show that the different ratio of blank and strengthhave a marked effect on the weld line movement. And the displacement of weld linecan be reduced by reasonable drawbead restraining forces.The conclusion which is got by the square-box part provides the instruction ofmethod and theory for the design and production of the inner door panel with TWBstructure.The weld line movement is the main defect in the stamping process of theTWB. To improve this problem, a new approach is presented to optimize the drawbeadrestraining forces and blank holder force in this paper. In the approach, a responsesurface method is employed for the optimization model based on the Latin-squareexperiment data, and a genetic optimization algorithm is adopted for minimizing theweld line movement under the restraint of crack and wrinkle. Numerical simulationsare then verified experimentally in an application of an inner door panel with TWBstructure. The results show that the weld line movement is greatly reduced and theformability is also improved.