I'll repost my question a little differently.
I have two steel members which I want to have act as a built-up member.
Now per section E4 (AISC-ASD) for a built up member the spacing of the
connections of the members should be such that the l/r < 3/4 of the
governing ratio of the combined member.
My question came in that say the actual kl/r value of the combined member was
80 meaning that the required l/r for the smaller members be less that 60. If
this ratio was not readily obtainable but lets assume 75 is, what if I base
the strength of the combined member on a kl/r of at least 100, rather like a
partially composite beam. Any comments or suggestions would be very helpful.
Bill King, EIT