LIASON_SOLIDE

Pasquale1985

Hi,
I am trying to simulate a rigid floor, having a rigid behaviour in horizontal (XY) plane, but leaving the vertical deflection free.
My models can have columns, beams and walls, without shell elements for floor slab.
I found the operator LIAISON_SOLIDE in documentation U.44.01 and R3.03.02. In particular, it is explained that in 2D case, the equations are:
DX(M)-DX(A)+yDRZ(A)=0
DY(M)-DY(A)-xDRZ(A)=0
and in 3D case, other equations are considered.
My nodes have all the degrees of freedom, and when I try to apply LIAISON_SOLIDE to the nodes of the floor, I always fall back into the case 3D. The result is a rigid body, without vertical deflection.

Is there a way to make the operator work only in XY plane, that is to say, the 2D case?
Or may you suggest another way to model a rigid floor in XY plane?

Best regards,
Pasquale

k_zurawski

LIAISON_SOLIDE is used to "solidify" the behaviour of nodes in that group, so they behave like rigid body. You may use it to transfer point load to a surface, point support or whatever you need it for when you need a rigid connection.

Overwan

Hello, I want to use LIAISON_SOLIDE in my model but I can't get any results when using it. I get a return of no such file or directory.

k_zurawski

Well, you know, there might be 100 reasons why you're not getting results. We are not magicians, we can't figure it out unless you share something...

Overwan

@k_zurawski#p74596
Hello,
I have a force applied to my plate in the -X direction, and I’ve fixed six screws to the plate. I would like to observe the Von Mises stress specifically on the screws, without the influence of the plate affecting the results.
My idea is to use LIAISON_SOLIDE to fix the nodes in the plate, so that the plate does not influence the behavior in the simulation.
Thanks in advance!

k_zurawski

I have to assume that force is applied to the vertical plate in X direction. Since you don't want to observe any influence of L bracket on your screws what do you need the plate for? If you get rid of the backet you may use one node, add 0D element to the node, apply force to that element and link bolts' flat surfaces (LIAISON_SOLIDE) to the 0D element.

Overwan

k_zurawski I didn't think about it, l try after having succeeded in automating my aster code with yacs.

NorbertS

Hello,
have you tried LIAISON_DDL? With this you can couple specific degrees of freedom.

Norbert