Learning Forum

[javat33489]

Faced the problem of fixing the SPH body with a solid body in the Ansys Workbench Ls-Dyna ACT and Explicit module.
It looks like this is an Ansys bug?
It is not possible to attach SPH bodies and rigid bodies to each other.
The LS-Dyna single module prepost has a TIED_NODES_TO_SURFACES pin that allows you to pin the rigid body segment and SPH of the body.
But ANSYS WB LS-DYNA ACT does not have this option.
Tell me, maybe it appeared in the 2022 version? Or is there another way?
I also tried using snippet but it didn't work. When exposed to the SPH body, it begins to slide over the solid body.
How to solve this problem in ANSYS WB LS-DYNA ACT?

[javat33489]

Hello. It looks like this is an Ansys bug?

[Reno Genest]

Hello,

Have you tried using an "asymmetric" bonded contact in WB LS-DYNA? The "asymmetric" option should create the *CONTACT_TIED_NODES_TO_SURFACE_OFFSET.

Reno.

[Reno Genest]

Hello,

To have a very solid connection between your SPH body and the rigid body, you could use "Rigid Body Additional Nodes" (*CONSTRAINED_EXTRA_NODES) to connect (add) certain nodes (really SPH particles here) to the rigid body. First, you will have to create a Named Selection of the nodes (SPH particles) you want to connect:

And then, use this nodal named selection in the "Rigid Body Additional Nodes" object:

The body in blue in the image above is the rigid body.

 

Reno.

 

[javat33489]

 

Thanks for the answer. I wanted to try. But in WorkBench there is no way to select the face of all nodes and have the Named selection be nodes? I can only select one node, but the named selection does not become nodes.

[Reno Genest]

Yes you can. If you create a named selection with a face, you can right click on the named selection and choose "Create Nodal Named Selection":

 

Or, you could select nodes directly and then right click and choose "Create Named Selection":

 

Reno.

[javat33489]

I is not work. I have errors.

I am trying to add a node selection, for that I need to have some named selection to click on it

[javat33489]

If I try to create a named selection on SPH and then click node selection on it:

Node selection not created...

[Reno Genest]

Hello,

Ok, you're right; the first method above does not work for SPH particles; you cannot create a named selection from a face and then convert it to nodal named selection. But, you can select the SPH particles directly using the node selection tool and create a named selection:

1. Select nodes.
2. Right click in the display window and choose "Create Named Selection:

 

Reno.

[javat33489]

Sorry sir, but this doesn't work.

If you select on the SPH node selection it gives an error in the construction tree on the left.

After the area is selected on the SPH grid, I tried to create a named selection and it gives an error like in the picture.

[javat33489]

What to do next sir? Does not help.