quick ways of estimating beam sizes

huangyhg

quick ways of estimating beam sizes
i would like to hear from practising structurals, and others, out there of quick and reasonably accurate ways to estimate beam sizes and weights when, for e.g., the aisc 9th edition (green book) or 13th edition (black book) are not easily available, when you are out on a job-site, when you just want to get some quick sizes before running your structural model in staad-pro, for instance, or when you want to do on quick check on a staad-pro output.
i have done my studying and research and have come across a few methods that might work. would like to hear your comments, and also your suggestions and advice on what are your favorite ways to estimate beam sizes quickly and accurately.  please be open-minded, think outside the box, and contribute in a way that can be beneficial and nteresting to all.
aisc 9th edition in chapter l (serviceability design considerations, page 5-181) provides guides for the depth of fully stressed beams and girders in floors (not less than fy/800 * span) and for fully stressed roof purlins (not less than fy/1000 * span).
also, an article in the engineer's notebok section of civil engineering (december 1971, page 67) provides some quick and reasonably accurate ways to estimate beam sizes.  this method for laterally supported beams and allowable fb of 24 ksi is as follows:
(a) required beam depth (d) in inches in 1/2 the span in feet.
(b) required beam weight (w) in pounds per foot is 1-1/4 times the total load (w) in kips,
(c) minimum deflection of required section in inches is 1/10 of beam depth.
if the required depth and weight do not approximate some available w sections, adjust by simple proportion.  examples can be provided, if needed.  please ask.
the above method, approximate and surprisingly accurate, is particularly useful for quick checking and estimating,  it was also highlighted by samuel marcus in his book, "basics of structural steel steel" (prentice-hall, 1981).
would like to hear from all of you out there of methods, or procedures, that you might have developed from years of working in steel design, that proves to be a quick estimate of beam sizes, weights and deflections that would really be of interest and benefit to everyone, esp. us "greenhorns".'
please remember that the "greenhorns" of today, still wet behind the ears, constantly being put in the "hot seat", sometimes chastised by our more experienced brothers for being "lazy", "not studying enough", "not researching enough", "not understanding enough", "seeking short-cuts", and sometimes being declared outright that we are "a danger to our profession" may turn out to be the tipmaster of the week years down the road.
thanks a bunch.

there was a rules of thumb in steel design aisc seminar a while back... aisc.org might have some info on it.  i have the little design card on my desk... here goes:
roof beam d=0.5l
floor beam d=0.6l
composite beam d=0.55l
beam weight=5m/d
section properties:
area=wt/3.4
ix=d^2(wt)/20
rx=.45d
ry=.25b
columns:  pa=area(30-.15kl/r)
tonnage:  psf=stories/3 + 7
.... this beam weight and column rules are for 50ksi steel.  m is moment, d is depth, wt is weight, etc.  you guys know the rest.
there's more info on the card.  i'll try to scan it tomorrow.
these are rules of thumb.  in reality, it may be easier just to tote your manual, a pen, and a post-it out in the field in your briefcase.
beam span / beam depth = or > 25 is probably to light.
beam span / beam depth < or = 10 web shear may control.
lc (max. unbraced length) is approximately 10 times compression flange width.
i req'd for l/600 = 0.31 m l (i=in^4; m=ft-kips; l=feet)
i req'd for l/360 = 0.19 m l (i=in^4; m=ft-kips; l=feet)
above equations for uniform load
jkstruct,
is l beam span? do you mean "roof beam d=0.05l..."?
the card says .5l.  i am too young to have actually attended the seminar, or i would know the answer.  
i think l is in feet and d is inches for this relationship.  that would make sense.  
check out:
good summary, thanks.
did a google on this and came up with the following general rule of thumb websites (yes i was bored).