ANSYS Beam 189 Section Properties Does Not Match AISC Section Properties
ANSYS Beam 189 Section Properties Does Not Match AISC Section Properties
(OP)
Hi All:
When using ANSYS Beam 189 element the section properties obtained for a square tube (6x6x0.5) is different from that obtained using AISC Section Properties table. Obvisouly, this is due to the corner radius, which is not accounted for in ANSYS Section.
The results are therefore unconservative. Is it still acceptable to use BEAM 189 with section properties defined using SECTION or should I used BEAM4 element and use the AISC section properties ?
Thanks,
StrainStress
When using ANSYS Beam 189 element the section properties obtained for a square tube (6x6x0.5) is different from that obtained using AISC Section Properties table. Obvisouly, this is due to the corner radius, which is not accounted for in ANSYS Section.
The results are therefore unconservative. Is it still acceptable to use BEAM 189 with section properties defined using SECTION or should I used BEAM4 element and use the AISC section properties ?
Thanks,
StrainStress





RE: ANSYS Beam 189 Section Properties Does Not Match AISC Section Properties
you say "Obvisouly, this is due to the corner radius"; so it sounds like you've looked into the difference and figured out how the difference came about. if it is due to "corner radius" issues, is it that significant a difference ?
why not use both elements to see the difference in the models ?
Quando Omni Flunkus Moritati
RE: ANSYS Beam 189 Section Properties Does Not Match AISC Section Properties
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RE: ANSYS Beam 189 Section Properties Does Not Match AISC Section Properties
Beam189 is a Timoshenko based beam element, which does incorporate shear stress and strain. Especially if you have a material that is even slightly anisotropic, such as many beams will be, this will at a minimum show a 3~5% difference for smaller deflections, which will increase and show a more obvious difference at large loads.
If you want to get to this level of considering end shapes, make sure to do material properties based off of directionality - depending on the material and manufacturing method you're looking at, a difference in strength there may show itself. For instance, if an I-beam was to be turned and loaded upon it's side, it would likely illustrate differences in response due to the manufacturing and crystal orientation internally, and not just its geometry.
As with all codes, FE or specified by groups like AISC, you can't take the values as exact in either case. One needs to investigate them and understand the assumptions being used.
That being said, if you are still that concerned with the geometry issue, then I recommend using one of the solid elements and creating the volume you need manually. Beam4 is a legacy element only for comparison to simple linear analytical results. It is not appropriate to use for actual design outside of demonstrating the differences in results.
I hope this helps,
Kherszal