In the static verification problems found in the online help,
there is the "T" cantilever beam given. At the given length,
2000in, the results compare quite well with the beam theory which
gives deflection = PL^3/3EI ~ 0.06%. However, if one shortens the
length of beam from 2000 to 1000, to 500, to 250in error increases
to 0.86%, 4.19%, 17.71% respectively. Why?.. is this a limitation
in the code or theory (Euler-B vs Timoshenko)? Any input on this
would be much appreciated.
Ben
Ben
T beam width is 200in and height is 60in..... so are you saying this is not related to differences in E/B and Timoshenko theory but rather load concentration?
Thanks again,
Ben
Thank you very much for that clarification and sketch....was a great help.
Regards,
Ben
thickness=(largest cross section dimension)=200in
Length=2000in, 1000in, 500in, and 250in
Ratio=Length/thickness=2000/200, 1000/200, 500/200, and 250/200.
Ratio = 10 , 5, 2.5, and 1.25
In engineering terms, the transverse shear distorts the transverse cross section for short beams. In Euler beam theory one of the assumptions is that the cross section stay perpendicular to the neutral axis and it is still plane. See the picture below.
Attachments
I made a slight mistake in the picture. I edited it.