Basic question on symmetry

Wernstrom · Sep 20, 2007

I have a basic question on using symmetry. I have cut my model in half in order to take advantage of symmetry and the point load is on the plane of symmetry. Should I use half of the actual load as the input or will Cosmos take care of that?

I have been told that I should halve the load, but I'm not entirely convinced. Is this something that is constant throughout FEA programs or does it depend on which one you are using?

rstupplebeen · Sep 20, 2007

That is consistent across FEA. Half the model half the load. Pressure on the other hand would be unchanged. If you are unconvinced do a simple case where a hand calculation can be used for validation like beam theory. Hope this helps.
Robert Stupplebeen

cbrn · Sep 21, 2007

Hi,
"symmetry" condition in FE (whichever the FE program) is an appropriate set of displacement boundary conditions. This does not impact loads nor this is a "switch" making the program "aware" of anything. So you will definitely have to halve the load. On the same concept, if you were dealing with cyclic-symmetry with 10 repetitions per circumference, for example, you would have to load your cyclic-sector with 1/10 of the total load.

Regards

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Basic question on symmetry

Wernstrom

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