Defininig contact surface's for loads in Abaqus submodeling

[mariomat83]

Dear all,

when the global model is subjected to more than one load, do we have to choose the contact surface's between global model and submodel for all loads in submodel or choosing contact surface's for one load only will define contact surface's for the other load's too?

Regards,

 

[Mustaine3]

It sounds like you don't know what submodeling is doing. Submodeling assumes that you run a smaller piece of the model, that gets the same deformation as that region in the global model. This you have to make sure with the submodel BC.

 

[mariomat83]

Mustaine3,

I'm running an analysis of a disc with a central hole (global model). BC is applied around that hole. The area around that central hole and the hole itself are cut to represent the submodel so I have the BC in the same position as in global model. If I remove the BC from the previous position and place it on the surfaces where the submodel is cut from the global model then resulting stresses are much smaller from those from global model and this shouldn't happened. Please check the photos to get a clear picture of the problem. What about the two loads applied to the disc? Do I also have to mark the global model/submodel surface's connection? If so, do I have to do it for both loads or for one is enough?

Regards,

 

[Mustaine3]

Make two pictures and show global model and submodel. Otherwise I don't know how to interpret your description.

 

[mariomat83]

Here it is....

 

[Mustaine3]

The load is deforming the global model and afterward that deformation is transferred to the submodel. That is what node-based submodeling is used for.

So just define submodel BC* on the inner and outer faces of your submodel.

*they are different than regular BC

See Analysis Users Guide 10.2.2 Node-based submodeling

 

[rrg1016]

The same loads and BC should be applied to the submodel. To transfer the displacements from the global model to the submodel use the BC that Mustaine3 indicates you.

Check page 24 for an example:

http://imechanica.org/files/l10-large-models_2.pdf

 

[mariomat83]

Thank you both for your help. Mustaine3, I applied the BC's as you suggested and the resulted stresses were OK. There was only small difference in stress results between mine and yours approach. The main reason why I was confused about connecting the submodel with global model is in some tutorials I watched where defining the connection surface's between submodel and global model was done for BC and load also.
Just to make it clear, if I have defined the connection surface between the global model and submodel for the BC, I don't have to do it for the loads also?

Regards,