Result measures and Identify result


I am trying to understand how to use "result measures" and "identify results".

I made a simple cylinder under axial compression with a force of 10 N on one end.

I am looking a reaction forces at the other end, where it is simply supported (although edge of a tiny center hole is fixed).

I am doing result measure on reaction forces, getting "mean average" of both z-component and magnitude.

Identify results enables me to export reaction forces from the same face.

Somehow there is a mismatch between the result-measure and Identify results. They give the same results for magnitude, while the z-component is slightly different.

Is there an obvious reason for that ? I have tried it in both NX 9 and NX 11. I am using the simple NX design license.





Re: Result measures and Identify result

It may be confusing, but remember that (most probably) you used metal (elastic) material with poisson ratio <> 0.

This means that if you fully fixed the bottom surface of the cylinder (whole surface, or edge in the way that the surface nodes are constrained with respect to each other), some of the nodes at the fixation sufrace try to move with respect o each other (distance between nodes on the supported sufrace 'is trying be changed due to load'), this creates lateral forces in the support. They are of marginal magnitude, however when you combine the Z & Magnitude reactions they will be slightly different. If you would create 'spider' (MPC) or model the beam with 1D element and create one-node BC, the results would be exaclty the same.