Dave Looman
Ansys Employee

As suggested in the previous post, it's not a good idea to solve for the rigid body motion of the plug as it flies toward the sheet.  For one thing that motion can be easily hand calculated.  Mainly though, the problem is that the plug will probably fly right through the sheet.  In one time step the plug will go from not reaching the sheet to being beyond it and contact will not have occurred.  The suggestion above avoids this and provides a good solution at the instant of contact.