Limit dome height and failure location of stainless steel tailor-welded blanks

Forming limits of stainless steel tailor-welded blanks (TWBs) are investigated through both testing and numerical simulation. Limit dome height (LDH) tests were performed for 1.2/1.0 mm TWBs with 0 degrees, 90 degrees, 45 degrees weldment orientations and various blank widths. Numerical simulation of the LDH test was conducted with LSDYNA. Since TWB is, in reality, a structure, the forming limits of TWBs in terms of the LDH and failure location should be characterized rather than the conventional forming limit diagrams (FLDs). A localized necking criterion based on the vertex theory was employed to identify the failure sites of TWBs. The localized necking criterion was compiled into a computer program, which processed the output data from LSDYNA. The LDHs and failure locations were computed for various combinations of blank thickness and weldment orientation. The predicted LDH and failure locations were compared with the test results and found to be satisfactory.