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In my analysis of the sheet metal forming process, I frequently found that the calculation could not continue and it terminated unexpectedly. Is there a way to avoid this?

In the forming analysis, there are several possibilities that will result in the failure of the calculation, they are:

a) The punch or binder moves too fast and impacts the unsupported blank introducing a dynamic effect which is significant in this simulation. The tooling velocity should be reduced to minimize any dynamic effect..

b) The time step is too big. In the card of *CONTROL_TIMESTEP, if the value of DT2MS is too large, then the mass of the blank will be increased correspondingly, and it will result in an increase of dynamic effects.

c) The mesh for the slave side is too coarse, and there is lot penetration of the blank into the rigid body. Refine the mesh for the slave side at this time.

d) Constrains contact is used for both side of the sheet at the same location. Use a penalty constraint for at least one interface.

e) The penalty coefficient SLSFAC is too large for this calculation, and requires a smaller value for the SLSFAC parameter.

f) There may be an initial penetration of the blank by the rigid tools, remove the initial penetration. Even though LSDYNA can check for an initial penetration, it does not guarantee that this problem can be solved satisfactorily.

g) Change (usually decrease) the value of XPENEN (under the card of *CONTROL_CONTACT)