A question about rigid body in contact simulation?

[R.Guo]

What kind of rigid body should be used as end points in three point bending, discrete rigid body or analytical rigid body. What the difference for these two?

 

[FEA way]

Discrete rigid parts can have an arbitrary shape since they are meshed with (rigid) elements just like a regular part. Analytical rigid parts on the other hand are limited to very simple smooth shapes (line, plane and so on) as they are not meshed but rather included as a mathematical description of their simple geometry. They are faster to solve.