Simple Compression test using Abaqus

I am trying to model a simple compression test (50% reduction in height) using Abaqus.

So for this, I have a lower die, Specimen and an upper die.

The dies are modeled as deformable, and I've also added reference points to both the dies so that I can add a rigid body constraint to both of the dies.

For the boundary condition, I've fixed the top die and for the lower die I've applied a velocity of 10. 

I'm unable to get a 50% reduction in height. Can someone please help me with this?