ABAQUS/Explicit - Initial Overclosure Adjustements + Rigid Bodies

[pirs]

Hello there,

I am relatively new to ABAQUS/Explicit and I am trying to model a cold-formed steel beam subjected to a displacement imposed by a rigid plate.

First of all, after I have defined my rigid body and its reference node, I impose a *Boundary condition and I am getting this warning:

***WARNING: BOUNDARY CONDITIONS ON RIGID ELEMENT NODES SERVE ONLY TO DEFINE SYMMETRY FOR CONTACT SURFACES (NODE 25 INSTANCE LOADBLOCK). THE REFERENCE NODE SHOULD BE USED TO CONSTRAIN RIGID BODIES.

I have made sure that the boundary condition is applied to the reference node. What is causing this and what exactly does it mean?

I have modelled both surfaces and I understand the master(rigid) and slave(deformable body) concept used by ABAQUS.

However, when I run my model, the .msg file shows a number of Initial Overclosure Adjustments that disconnect my surfaces in a way that connection is lost between them. What exactly is causing this and what may be the consequences in terms of final result?

Thanks for any inputs on this.