Question on connecting truss elements to flat sheet

[picoso_13]

Good afternoon to all,

I have a question for all the great forum people. Let say I have a truss element (2D) that extends perpindicular to a flat sheet (2D). The truss element then connects to the sheet at one end, at 90 degrees. Boundary conditions aren't really important for my question so lets just say that the flat sheet is constrained at all four edges.

My question is: Will the connection point (truss to sheet) allow for moments to be transfered from one to the other, or will they just allow translational? (The load applied at the other end of the truss element would be in any xyz direction)

If it the connection allows moments and translational loads transfer, how would I go about eliminating all moment transfer capability, to act more like a pin connection?

Thanks for reading, and double thanks for responding.

Carbon

[John_Holtz]

Hi Carbon, welcome to the forum.

If you really mean that you are using truss elements, then all joints are pinned. A pinned joint can only transmit forces in the axial direction. You do not have an option to make them a moment connection. (This is known as having 3 degrees of freedom: translation/forces in X, Y, and Z.)

On the other hand, beam elements are a moment connection. They transmit forces and moments in all six directions. (Beam elements are six degree of freedom elements: translation/forces in X, Y, and Z, and rotation/moments in X, Y, and Z.) "End Releases" can be added to an end of a beam to release any of the 6 degrees of freedom.

This is probably more Finite Element Analysis (FEA) theory than you were hoping for. If not, turn to the following page in the Help documentation: "Help > Autodesk Simulation > Getting Started > Nodes and Elements".

[picoso_13]

Astro,

Thanks for the reply, that is exactly what I was looking for. I should of thought about it more closely, but what you wrote makes perfect sense. I have briefly used Patran/Nastran, and I know they have the option to eliminate any of the 6 DOF. The "End Release" is what I was looking for. I'll have to investigate it to make sense of how to use it. Thanks for the answer, I can now proceed with my model.

On a side note, I am trying to model a square channel using 2D plate elements (I don't want to import any solid models). Ideally I would like to just make all 4 surfaces of the hollow channel an then mesh them. But some reason, ALGOR seems to like it only when you sketch in XY (I think it's XY, can't remember which plane at the moment), then it lets you easily 2D mesh, otherwise the option is not available (for some reason it treats anything outside this plane as 3D stuff).

Carbon