Learning Forum

[Sand_1234]

Hi everyone,

I am not sure why this three story structure shows rigid body mode. I would appreciate if you can put some comments on rigid body modes (what causes this) or any other probable reasons for this results?

I used Ansys Spaceclaim to model the geometry and the bottom nodes are fixed. I did not define the connection between the members. Do I have to define the connection? If not, how are the joints connected?

I am modeling truss next, do I have to define the connection of the members in the truss?

Thank you for the help.

[Erik Kostson]

Hi

The members are not connected as you can see from the image showing a rigid body movement. So they need to be connected.
Easiest ways in:
In spaceclaim you can use shared topology to connect all the beams/line bodies at their common vertex so they are then connected when we mesh them in mechanical. Search for shared topology videos.
If you do not share topology then you would need to manually create joints connections between them.
Or use node merge in mechanical which will merge common nodes that are onto top of each other at a vertex location.

So 3 ways, I would suggest the first one (shared topology).

Erik

[Sand_1234]

Hi Erik This helps. Thank you .