ASD LOAD COMBINATION OR LRFD COMBINATION????
ASD LOAD COMBINATION OR LRFD COMBINATION????
(OP)
I am currently working on investigating a truss using AISC code. I am confused whether what type of load combination to use. Whether to use ASD load combinations or LRFD load combinations or even both. WHAT TYPE OF COMBINATION SHALL I USE ANYONE????






RE: ASD LOAD COMBINATION OR LRFD COMBINATION????
RE: ASD LOAD COMBINATION OR LRFD COMBINATION????
RE: ASD LOAD COMBINATION OR LRFD COMBINATION????
If you are looking at this truss, it must be because something is or has changed - more loads, etc. If it is a retrofit, then the current Code's loads, etc. should be used with either analysis method being acceptable.
gjc
RE: ASD LOAD COMBINATION OR LRFD COMBINATION????
RE: ASD LOAD COMBINATION OR LRFD COMBINATION????
Note also that todays ASD is very different than earlier ASD methods. Really ASD and LRFD with respect to the steel code only differ in the way load factors and safety factors are applied - they typically give results within a few percent of one another.
RE: ASD LOAD COMBINATION OR LRFD COMBINATION????
RE: ASD LOAD COMBINATION OR LRFD COMBINATION????
RE: ASD LOAD COMBINATION OR LRFD COMBINATION????
If you are checking a roof member, I am typically not shy about maxing out the member as I really feel that getting a full 20psf live load on a roof member is not likely unless someone has stacked a bunch of materials in one spot, or there is a party on the roof.