Slenderness ratio requirement for compression members in AS4100

[hrbrt372]

Hi,

Is there a recommended slenderness ratio in AS4100 for compression members, similar to AISC's kl/r <=200 for compression members? I have a 12m -200UC52 interior post that works with strength as the load is too little, only about 90kN.


Thanks,

Herbert

 

[rowingengineer]

there is no code limit but kl/r of 200 is about right

http://www.nceng.com.au/

"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."

 

[Agent666]

In NZS3404 which is essentially identical to AS4100 with a few minor differences, there is an implied limit of 320 for member slenderness. The equivalent NSZS3404 table to AS4100 table 6.3.3(3) has no values over 320 for all values of alpha_b except 0.5. In the commentary it notes the following

"The values of αc given for modified member slenderness ratios from 340 to 600 under the section
constant αb = 0.5 are for use in determining the bearing buckling capacity of webs in accordance
with 5.13.4. Values of modified slenderness ratio up to at least 540 are possible in this application."

It doesnt specifically give a limit but I would interpret this as the limit being 320 or lower (which is pretty slender!

Table 6.3.3(3) in AS4100 has values for all alpha_b's up to 600 by comparison.