Study On Forming Of Differential Gauge Tailor-welded Blanks Based On Numeric Simulation

In recent years, the automotive industry has paid a great deal of attention to weight reduction and fuel economy. Hence, tailor-welded blanks (TWBs) are commonly used in automotive panels manufacturing. A tailor-welded blank (TWB) consists of two or more sheets that have been welded together in a single plane prior to forming. The sheets can be identical, or they can have different thickness or mechanical properties. In this paper, different gauge TWB has been studied about its formability. Since different gauge TWB has many combination mode due to the different blank has different gauge and mechanical properties, therefore adopt conventional methods to study the formability of TWB is difficult, because there are two many experiments to do and the blanks are not always available. But the method of finite element (FE) can offer an efficiency tool to study the formability of TWB based on single sheet mechanical properties. So in this paper finite element simulation software eta/Dynaform is applied in the study.In the process of TWB forming, there are many factors effect on the formability. In this paper, the thickness ratio, the different mechanical properties combination and weld line position which play important role in the process have been studied. In order to fulfill the study efficiently, the square box model is applied in the study and the criterion to evaluate the formability of TWB is presented.With the FEM software eta/Dynaform various forming condition were simulated in square box deep drawing process. The simulation results presented by the diagrams and the results were discussed. First the thickness ratio plays the most important role in TWB forming process. As the thickness ratio goes bigger the formability of TWB goes worse, but this tendency is not linear. Second the different mechanical properties combination brings the TWBs' formability down, the tendency just like the thickness ratio effect on it. But the difference of mechanical properties plays minor in effect on the formability. The last is the weld line position of TWB. According to the simulation results that if the weld line offset is bigger to the parts geometry center the formability is worse.At last, a real TWB part, the center pillar of car door was simulated by eta/Dynaform and according to its simulation results designed the die. Moreover the die,...