Column Slenderness Ratio > 200
Column Slenderness Ratio > 200
(OP)
Does anyone have a reference which specifies the limits for columns with a slenderness ratio greater than 200?
I have read several of the column posts and have referenced most of my textbooks and the best information I have found states "columns bounded by l/r < 200".
I have a safety factor of 2X the design load as compared to the critical column buckling load, however, l/r is 218.
Pcr = 200,000 lbs
Pdl = 100,000 lbs
This may be more of an academic interest at this point, however, I would like to understand the behavior above 200.
I have read several of the column posts and have referenced most of my textbooks and the best information I have found states "columns bounded by l/r < 200".
I have a safety factor of 2X the design load as compared to the critical column buckling load, however, l/r is 218.
Pcr = 200,000 lbs
Pdl = 100,000 lbs
This may be more of an academic interest at this point, however, I would like to understand the behavior above 200.






RE: Column Slenderness Ratio > 200
KL/r<200 is a code privision, no?
RE: Column Slenderness Ratio > 200
RE: Column Slenderness Ratio > 200
Assuming you are using AISC, with a slender column you'd be using equations E3-3 and E3-4....you'll just have a very low Elastic Critical Buckling Stress.
RE: Column Slenderness Ratio > 200
Dik
RE: Column Slenderness Ratio > 200
RE: Column Slenderness Ratio > 200
RE: Column Slenderness Ratio > 200
Dr. Joseph Yura, speaking at a seminar once, commented that the compression formulae for columns applies past KL/r = 200 but that at higher slenderness levels, all those secondary influences on buckling become much more influential on the column stability.
Secondary influences might include unexpected lateral loads, construction out-of-plumb installation, eccentricity from insufficient bearing plate grout, load eccentricity at the top of the column, unbalanced loading, etc.So the 200 limit is still preferred.
Even if a design (architect) called for a skinny column, I might still use a very thick section and perhaps fill it with concrete to overcome any heebee jeebees I might have with a high KL/r.
RE: Column Slenderness Ratio > 200