Critical buckling length..

[Anonymous]

I know there is many topics about this subject but once more.. 🙂

So Can you help me for calculate critical buckling lenght for upper chord. If I got this kinda buckling shape and I got this kinda numbers.. I cant clearly understand or I am not  sure what this critical coef. and precisions means maybe because my english skills isnt very best..

see attachment pics..

Thanks allready 🙂

[Artur.Kosakowski]

The buckling analysis in Robot is not intended for finding buckling lengths of elements of the model. This is the check of the stability of the structure as a whole. The critical coefficient is the information about the value of the load that would cause the structure (or its part) to loose its stability. The value of this load is equal to the load defined in the selected load case * critical coefficient.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[Rafal.Gaweda]

Check also messages 2 and 7 here:

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Buckling-Analysis/m-p/3280269

[Anonymous]

Ok.. I just read one kinda research where researchers is calculating backyards critical buckling lengt with robot?

Pdf below in finnish but see pictures 🙂 

And other one in English 

[Artur.Kosakowski · Accepted solution]

If you insist you can do the following:

1. Determine the mode (shape) that corresponds to the buckling of the element you want to calculate buckling length for

2. Check the axial force in this element for the selected load case

3. Multiply this force by the critical coefficient for the determined mode from the point 1

4. Calculate buckling length based on the determined value of the element's critical force (point 3)

Mind that the success depends on the correct execution on point 1 and the decision which mode and element to investigate is now in your hand 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[Anonymous]

Ok I Think I got it most of parts..ofcourse step by step instructions with pictures would be nicer but first I can try it myself  😉

ps. Thank you !

[Artur.Kosakowski]

Handle with care

Please note that I'm not in the position to determine which mode to choose for which element of a model.

[Anonymous]

Hehe I Know, this is only for studying the subject not for real structure calculating.. there I stand in Eurocodes buckling lengts for the chord in compression

Thank you very much!! 🙂