What kind of velocity pattern is better for metal forming analysis?

Smoothly changed velocity pattern is found to be better than the others, especially for springback analysis. However, using a complete (or half) sine wave is physically inaccurate and numerically not providing great benefit. Though the ram of a mechanical press does move following a sine wave pattern, the ram stroke (typically about 20 inches) is much greater than the actual draw depth (typically 4” to 6”). It is only the tail end of the sine wave governing how the dies are in contact with the blank. The pattern will be very different if a double action press or hydraulic press is used. A sinusoidal velocity curve always minimizes dynamic effect between the deformable blank and rigid tools!!