Dear David,
First at all the RBE3 is a NX NASTRAN and FEMAP finite element type-only, in Ansys do not exist a similar element, then FEMAP translate it as CP coupling constraint commands or CERIG commands.
Second, revise your model, if you were the only author (or creator) of the FE model then you will know what commands you used to create it: only exist a command in FEMAP that created both mass element and rigid element, that is command "Tools > Mass Properties > Solid Properties" that will ask you to select a solid and the next question is "OK to create a representative node and mass element?", the next prompt is the density (by default 1.0), and finally will ask you "OK to link mass to mesh?". Well, at this point I suggest to cancel command because FEMAP don't allow you to specify what type of RIGID element to create (RBE2 or RBE3), then is better to make this process "by hand": after cancel command, FEMAP will create a 0-D MASS element (named CONM2) + node at the center of gravity of the solid. FEMAP also will create the property associated to this element. Simply edit the property to enter the correct mass value.
The final step will be to connect the above MASS element with your supports: simply use command "Model > Element > TYPE = RIGID" and make sure to select RBE3 (interpolation): here select the MASS NODE as DEPENDENT and all the support nodes as INDEPENDENT. Click on NODES to select nodes using METHOD = BY CURVE, etc. Regarding DOF, make sure to select TX,TY,TZ only in both DEPENDENT & INDEPENDENT fields (desactivate rotations).
And you are done, you have created your first SPIDER RBE3 element, a "feature" unique in FEMAP!!.
Please let me know if this is what you did in FEMAP session.
Best regards,
Blas.
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Blas Molero Hidalgo
Ingeniero Industrial
Director
IBERISA
48011 BILBAO (SPAIN)
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