Model union between two different meshes (Patran)

[Alejandro C]

Hi, following the problem that I tried to describe in the attached picture:
I have a complex model in which I have two structures: a primary and a secondary structure.
The primary structure deforms, and the secondary structure will follow that deformation because it is attached to the primary structure in several parts.
Mergin both models would be too time consuming and we want to keep different levels of mesh refinement on each structure.

What is the best way to tell Patran to make the secondary structure have the same displacement than the primary structure in the connecting parts? Take into account that nodes are not necessarily coincident and that one mesh is finer than the other.

Is it possible to do this using CBUSH or RBE2 elements for example?

Thank you,

Alejandro

 

[VN1981]

Rigid Body Elements are certainly one way to go. Just remember that 3D solid elements do not have rotational capability which 2D Quads have. This incompatibility can be bridged by RBE2 elements.

Similar options can be tried with CBUSH as well theoretically by adjusting translational & rotational spring stiffness. I would suggest doing very simple tests for which you have well defined analytical solutions available. For ex: A simple tension and torsion tests.

Another option could be to use Glue Contact. I am not sure how much gap is here between the 2 surfaces but I think there should be an option to specify gap distance in contact formulation to overcome non-contacting surfaces.