EXPERIMENTAL-VERIFICATION OF SUPERPLASTIC SHEET-METAL FORMING ANALYSIS BY THE FINITE-ELEMENT METHOD

The numerical result for superplastic sheet-forming simulation is comp ared with the experimental result to verify the validity of the finite -element code developed. The code calculates the optimum pressure cycl e, the deformed shapes, and the distributions of the strain and strain -rate in the blow-forming processes. The calculation deals with the ma ximization of the strain-rate sensitivity, the protection of the local ized deformation, the consistency of the desired strain-rate, and the control of the hour-glass mode and locking phenomenon. The comparison demonstrates the validity of the present algorithm and its results, es pecially in respect of the optimum pressure cycle, where there is only a slight difference between the two results.