Research Of Curvilinear-Weld-Line TWB Stamping Forming And VBHF Optimizing

In recent years, because of energy shortage and increasingly serious environmental problems, weight reduction and fuel economy becomes one of the main objectives of the automotive industry in and abroad. As an important approach of the light–weighting technology, tailored-welded blank (TWB) has been widely concerned and broadly used in the automotive manufacturing industry. Previous resolutions on the formability of tailored-welded blanks are mostly stayed in linear-weld-line TWBs. In fact, compared to the linear-weld-line TWB, curvilinear-weld-line TWB is more flexible on the layout of the weld-line, and also it has more advantages on the sheet weight reduction and TWB stamping capability.Many parameters play very important role in the stamping process of curvilinear-weld-line TWB ,such as weld-line shape, different mechanical properties of sheet metal that compose TWB, thickness ratio, blank-holder force and so on. On the basis of the research about these parameters impact on the formability of TWB, a square-box is chosen as the research object, three different types of curvilinear-weld-line TWB square-boxes are numerically simulated by Dynaform software, weld-line shape and thickness ratio that affect the TWB formability are analyzed, the dome height and weld-line movement of curvilinear-weld-line TWB are studied under the influence of these factors. Different types of constant blank-holder forces and variable blank-holder forces on the curvilinear-weld-line TWBs which have better formability were simulated, the optimum layout approaches of variable blank-holder forces are selected.The results show that changes of weld-line shape and thickness ratio have significantly different effect on the formability of curvilinear-weld-line TWBs. The optimum layout approaches on three kinds of curvilinear-weld-line TWBs are different, stamping capability can be increased by the optimization of variable blank-holder forces. Research contents in this paper have important theoretical significance on curvilinear-weld-line TWB forming optimization and its selection and application in industrial production.