StaadPro Buckling Analysis

[culture9]

I need someone to show me the steps to perform buckling analysis in staadpro.
E.g: A steel strut 0.15m diameter and 12m long, built in rigidly at the bottom but completely unrestrained at the top. Ans = 89.4kN. Take E= 205GPa.
I have tried tirelessly but still cannot get the correct factor.
Please do help by sending me a stepwise description of the process and possibly a staadpro file containing the solution.
Thanks.
atika4ufolks@yahoo.com

 

[SethGuthrie]

You might try the Structural Analysis and Design forum on Be Communities here:

http://communities.bentley.com/products/structural/structural_analysis___design/f/5932.aspx

I see a few buckling analysis posts there already.

http://communities.bentley.com/prod...is___design/f/5932/p/87897/248240.aspx#248240

 

[izax1]

Sorry, I cannot halp you with STAADpro. In danger of being regarded as overly pessimistic, I would be very careful with doing buckling analysis with numerical methods. A buckling analysis is very dependent on geometry. And the real geometry (reality) is not perfect, whereas the numerical system assumes it is. (just try to model a perfect (100% straight) strut and one with a slight imperfection, you will see ahuge difference in buckling load) Of course you can include uncertainty factors, and with the right parameters and large safety factors you can calcualte a reasonable buckling load. I prefer hand calculations or non-linear buckling analysis.

 

[IDS]

I can't help with STAADPro either, but a linear buckling analysis should give a result very close to the Euler buckling load, and to a non-linear buckling analysis.

Based on the information provided the numbers I get are:

Euler buckling load: 87.29 kN
Linear buckling analysis (1 segment): 87.95 kN
Linear buckling analysis (10 segments): 87.29 kN
Non-linear buckling analysis (10 segments): 87.47 kN

What buckling load are you getting from your STAADPro analysis?

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[culture9]

Thanks everyone.. Sorted myself out already. I was modelling wrongly initially using staad plane instead of space. Got 87.29kN.
Thanks.