Hi

I was trying to find out the results of a cantilever beam with an end load and trying to match results with Handcalc/ Autopipe and CAESAR.
A short beam indeed with L/D around 15. My handcalc results & FEA results were little different ( because my PL3/3EI neglected shear deformation effect) and hence wanted to clarify.

I have two questions

1. Does CAESAR II use TIMOSHENKO beam for its 3D beam element or EULER BERNOULLI?

2. Is there a way I can input shearmodulus into CAESAR?.I wish to input a higher value of shearmodulus to remove the shear deformation effects for academic interest and compare with handcalcs.

Any reply to this would be appreciated

brittlespring
----------------------------------------------
as useful as my name suggests ;-)

Hi,

Could anyone reply to the above question?

Thanks

The hand calculation should give you the same results as the CAESAR II run, to less than 1% error. Remember you only have accuracy to about 6 digits with the software.

See the attached ZIP archive for an example (5.30) CAESAR II job and an accompanying Excel file.

Hi Richard & Brittlespring,

Richard - Thanks for the spreadsheet and model in the zip file. It is a good example of a verification we should all do.

I extended the model and calculation to include 10 cases altogether with beam lengths between 1 to 10 feet. The issue that Brittlespring talks about shows up in short beams.

I extended the calculation to include the effect of shear deformations. "Mechanics of Materials" from Timoshenko & Gere is a good reference for this. I tried to do my best to include references for the inevitable questions.

I just did the calc, and I don't want to offer too much interpretation of the results, other than to say that it looks like Caesar does account for shear deformations (beyond basic Euler-Bernoulli calcs.) This is a good thing, and I now have full confidence in how Caesar handles short beams.

Richard - Please review the attachments. I based them on the files you had, but I have been known to make sloppy mistakes. I appreciate your opinion, especially if you can find out the exact terms used in the Caesar stiffness matrix.


RAC


(I can't attach excel files, so I printed my "cantilever_10 cases" spreadsheet as a PDF. I think the PDF is documented enough that anyone could recreate the results.)