Prior sheet buckling leading to wrinkling formation in a gas forming a V-trough with wavy bottom

2-D computer simulation of gas-forming process for the small size specimen with 3rd kind pre-form. The explicit code 2-D LS-DYNA may be used to accurately model the wrinkling occurrence and sites of aluminum sheet during superplastic forming. The power law equation can be used as a constitutive model for superplastic forming.