Modelling a Pin-Jointed Truss - Patran/Nastran 1

[ferryscott]

I am trying to model a pin-jointed truss for buckling analysis.

Simple Example Case (2D):
Node 1 (0,0)
Node 2 (0,2)
Node 3 (1,1)

Element 1 - Node 1 to Node 3
Element 2 - Node 2 to Node 3
Properties A E I

Nodes 1 & 2 are constrained in displacement, free in rotation.

Unit load applied at node 3 vertically downwards.

I cannot work-out/find how to model the pin joint at node 3 so that both of the elements have their own degree of rotational freedom at the node.

If anyone could help it would be greatly appreciated.

Best Regards,

Scott

 

[Spirit]

Hello ferryscott,

assuming you are using CBAR elements, you can activate the pin release flags on the CBAR card. These are to be defined in the fields 12 and 13: putting "456" in these fields should fit your needs.

Regards,

Spirit



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