Allowable Loads Suspended From Beam Flanges
Allowable Loads Suspended From Beam Flanges
(OP)
Does anyone have any info on how to calculate allowable loads hanging from the lower flange of S shape and W shape beams? i.e. underhung crane trolley
Thanks,
Matt
Thanks,
Matt






RE: Allowable Loads Suspended From Beam Flanges
Once so dimensioned, a more proper check would be the identification of some (maybe dihedral, 2 symmetrical triangles) lines of roture mechanism that gives the plastic solution to the local rupture consistent with the position of the load, and then see if you have enough safety factor.
RE: Allowable Loads Suspended From Beam Flanges
If you have any way of getting hold of a copy of the Australian Crane Code AS 1418, you will find the design of monorail beams well covered there. (I would be a little surprised if other crane codes didn't cover the problem just as well).
As well as considering transverse bending in the bottom flange (as ishvaag has indicated), you need to consider the local longitudinal stresses (which must be combined with the main beam bending stresses).
From memory, I think that the Aus Code lets you go very close to full yield stress when combining tensile stresses due to local and global bending (ASD design). Since there is matching local compression on the top surface of the flange, yield at the bottom face is very much a local effect, with no adverse consequence on the global strength of the beam.
You also need to consider the effect of out-of vertical loads, which can produce excessive bending stresses in the web. These may be reduced somewhat by proper design of the supports to the top flange. If they permit some degree of torsional rotation, then the web may deflect to reduce out-
of-plane loading.
RE: Allowable Loads Suspended From Beam Flanges
RE: Allowable Loads Suspended From Beam Flanges
RE: Allowable Loads Suspended From Beam Flanges
RE: Allowable Loads Suspended From Beam Flanges