How to model bonded elements (only one part?)

[NicoleCaio]

Dear All,

I'd need to model the behavior of a part of a ship deck structure on which is bonded a steel plate with an adhesive epoxy compound. In first approximation I would like to represent a perfect bond, in order to get the stress distribution on the structure without caring about debonding issues.
I've created only one part in Abaqus CAE with three different solid features (selecting "keep internal boundaries" for each solid-extruded) for the deck plating, the adhesive layer and the steel plate, assigning different material properties and meshing them separately.
I used solid homogeneous sections and 3d stress element for the mesh.
I took care to have partitioned the deck plating so that the central surface on which there will be the bonding on, it has meshed in the same way of the layer above.
Are the nodes of the surfaces in contact already shared, being all the structure on the same part? should I define some constraint between the bonded features?
I had the warning “There are 3 unconnected regions in the model”, so I've tried with a surface-based tie constraint between the deck and the adhesive and the adhesive and the steel plate.
Then I receive these warnings:
“No constraint is formed for the tied pair (assembly_slave_surf_adhesive, assembly_mast_surf_deck) . All the slave nodes are part of the master surface.”
“No constraint is formed for the tied pair (assembly_slave_surf_steel, assembly_mast_surf-adhes). All the slave nodes are part of the master surface.”
and still the previous one.

many thanks in advance,

Nicole

 

[rstupplebeen]

In the assembly module you can boolean combine the 3 solids retaining the boundary. Assign the appropriate materials to each solid in the part, mesh and proceed as normal. Now it's 1 continuous mesh. I hope this helps.

Rob Stupplebeen

http://www.optimaldevice.com

https://sites.google.com/site/robertkstupplebeen/

 

[NicoleCaio]

Thank you rstupplebeen for your answer.
I've tried to do as you suggested, but it seems that the loads is not transferred through the different bonded layers. In fact both the bonded plates (the adhesive and the steel plate) have a nearly to zero stress.

I've tried also to create different parts, assembling them and defining position constraint "face to face" for both bond interfaces and applying tie surface constraints. The results seems quite better but I'm still not sure about the load transfer.

In your opinion, how can I make sure that the load is correctly transferred between the bonded surfaces?
in attachment you can see the two different results I had. I applied a surface traction (195 MPa), (see picture).

Thank you for your time

 

[NicoleCaio]

p.s I put a clearance of 0.03 for the position constraints: only in this way I managed to have tie constraints between the two couple of bonded surfaces.