ABAQUS Multiple constraints in same point

[SimonMK]

Hi

I am using Abaqus/Standard to model a sandwich beam. Right now I am making a 2D solid model to validate my results (later I want to make a 3D solid model). I know it would be easier to make a shell model but later I will need to implement a 3D solid model.

My problem is that I want to make a simply supported sandwich beam with a uniformly distributed load. However, I need to use Tie constraints in order to constrain the face sheets and core together. I also need to use MPC Beam at the edges in order to make the edges rotate around the midplane of the sandwich beam. The MPC and Tie constraint are colliding at a point on the edge (see image) which causes the model to be unsolvable.

Is there any way to avoid this problem?

Thanks in advance.

 

[FEA way]

There are several other approaches that you could use to model the connection between the layers and to prescribe the rotation to the sides. However, you said that you need to use tie and MPC constraints so I assume that you can’t change to any other approach. In such a case you could try editing the surfaces included in the tie constraint definition and removing the individual problematic nodes from those surfaces.

 

[SimonMK]

Thank you for your reply.

I might have been to quick in my formulation, I guess I don't "need" to use tie and MPC constraints, however those are the methods I know can do what I want. So if you have any other methods to do the same I would very much like to hear those.

When you say I could try to edit the surfaces in the tie constraint, you mean doing a mesh select and not choose the elements at the edge right?

 

[FEA way]

You could try using tied contact or merging the part instances. For rotation application I would consider rigid body or coupling constraints.

Yes, you can use mesh-based selection and deselect individual nodes.