lrfd vs. lfd

huangyhg

lrfd vs. lfd
could someone please explain the basic differences between lrfd (as used in aisc manual of steel construction, or aashto bridge design specifications) and lfd (as used in aashto standard specifications)? i have a good working knowledge of lrfd design, but have had much less exposure to lfd design. i鈥檝e noticed that even in lfd design some resistance factors are used, although the absence of the 鈥淩鈥?in lfd seems to imply they are not used.

do a search on this on this site. in this forum, there was a very long discussion on lrfd and working stress approaches.  you might find some good information there.  thread was about 2 to 3 months ago.
it's thread#507-56224, started by jheidt2543 on may 15/03.  topic title:  factor of safety questioned.
here's a quick link to it: