Engineering Power Tools - Slenderness Ratio

[GTDan]

Good morning and Merry Christmas.

My question is in regards to buckling in columns. I started using the Engineering Power Tools download to check my calculations. I have run into two challenges I hope you can help me with.

1. I get a different critical load when using Johnsons formula. I have checked my hand calcs over and over. I know it is right as I am using a textbook from college for a reference.

2. The slenderness ratio calculated by the software is different than what I solve. I also noticed the slenderness ration does not change when the end conditions are changed (ie fixed-fixed, fixed-free, etc).

I am calculating the slenderness ratio by multiplying the end condition constant (K) by the length and dividing the result by the radius of gyration.

Is this wrong, or is there a flaw in the program? Any thoughts?

Daniel

 

[cntw1953]

Yes, you are correct.

Try a few cases with different end conditions (set L/r = 1) and check the results (k). If still do not agree, send them an inquiry and let us know the answer.

 

[GTDan]

Thanks for the input, cntw. I have sent an email to their support group. I will let you know the response.

Does anyone else use this program? I just downloaded it yesterday as a coworker pointed me in the direction. I have let him know of the issue I have, but have not heard a response.

 

[desertfox]

Hi GTDan

I have not used the tools to which you refer however I have a link here to another online calculator which might be of use:-

http://www.tech.plymouth.ac.uk/sme/desnotes/buccalc.htm

The slenderness ratio is L/r where L is the length of strut and r is the least radius of gyration of the section.

desertfox

 

[desertfox]

Hi again

Here is another which might be better than the last one

http://www.tech.plymouth.ac.uk/sme/desnotes/BucklingB.htm

desertfox

 

[GTDan]

Thanks Desertfox. I will check them out

 

[Ron]

Euler's equations work nicely....I use them routinely.