I'm having some issues with looking at the stresses in the cross section of a beam. I have the beam elements as follows
As you can see, it's made up of beams of various cross-sections, including to beam elements that are tapered beams.
The issue I'm having is with the tapered beams, more specifically, extracting the cross-section stresses in the tapered beams. When I use the View-->Advanced Post--> Beam Cross Section tool and select Element 124, I get the following results (notice that I'm looking at axial stress, and only using the axial force in the calculation):
As would be expected, the stress is constant throughout the cross-section. As I wouldn't expect, however, is that the stress is constant through the length of the tapered beam. The axial stress should follow this relationship:
σA = FA / AA
σB = FB / AB
For this output set,
FA = FB = 46.536
AA = 5.067E-6
AB = 6.207E-5
This should give the following stresses
σA = 46.536 / 5.067E-6 = 9.184e6
σB = 46.536 / 6.207E-5 = 7.497e6
As you can see in the image above, the axial stress is the same at end A and end B (9.184e6, which is what it should be at end A).
Am I doing something wrong, or is this a bug in the beam cross-section tool? To me it seems like it's not using the correct area at End B. Perhaps this tool doesn't work for tapered beams.
Below is the property card for the beam element in question. Any feedback would be appreciated.
EDIT to add: This issue has been seen on Femap Version 11.4.0. I'm not aware if this problem existed on previous versions.