submodelling techique- help

[Mohamedsayed]

Hello there,

I have used a simple model to understand sub-modeling technique, but i failed, and i need your help.

The model is 3D model (block). A uniform distributed load was applied on the top surface of the block, the bottom surface of the block is fixed in all directions, while the edges of the block was constrained in the x and y directions. A gravity load was applied throughout the body in the z-direction.

I am interested in the middle region of the block (central region), so i want the submodel to cover that region.

That is what i did: but it did not work

1- I generate the global model (3D-block) and run that global model.

2- i made copy from the global model, then from Edit Model Attribute, the submodel will read data from the global model.

3- i cut the region that i want for the submodel (centeral region of the block) from the Global model.

I am confused about how to apply BC. and loads on the submodel. Since i copied the Global model to generate the submodel, so i sill have the BC. and loads that was applied to the Global model. I need to understand how can i apply the Loads and BC. on the submodel.

4- I chose the boundary (edges of the submodel) to apply the B.C. using (BC>> others>> submodel, also i suppresed the boundary conditions that was existed in the Global model.

5- I suppresed the loads that i was applied to the Global model.

Please remember that the submodel was copy from the global model, so all loads, BC still there.

These procedures does not work to generate submodel. I wish someone help me.

Thanks

 

[Mohamedsayed]

Hello everyone,

I am confused about Applying the loads and the Boundary conditions to the submodel,

Regarding the loads, there was a uniform distributed load on the global model, so shall i apply this load again on the submodel? or it will automatically transferred to the submodel through the driving nodes.

Regarding the BC., the bottom of the global model was fixed, shall i fix also the bottom of the submodel.

I wish someone help me understand how to apply loads and BC. to the submodel.

Thanks

 

[portliner]

You shall apply the distributed load to the submodel, I suppose it is the gravity.
You shall better prepare the interface between global- and sub-model. Thie global model drives the sub-model by inposing the global nodes displacement onto the sub-models coresponding nodes by interpolation. Node compatibility is NOT nessescary in the interface(s).
Your question aboute BC: If your sub-model extends right to the bottom You should apply the same BCs to the sub-model here.

 

[Mohamedsayed]

Thank you very much Portilner,

My Global model is subjected to Kinds of loads, the first load is Uniformely distributed loads on the top surface of the model, the second load is Gravity load.

So, you advice me to apply all kinds of loads to the submodel. Right? Hence i should apply both distributed load and Gravity loads to the Submodel.

Thanks for helping me.

 

[portliner]

Caution about loads, You should applly loads to the submodel ONLY if the load acts on the subregion. Fpr example a presure load on a certain surface of the global model should NOT be applied to the sub-model IF this sub-model does NOT extend right up to this loaded surface. The gravity applies to everthing and should be applied by You on the sub-model.