Oct 14, 2012 The evaluation of elastic moment for built-up crane runway girders is not an easy task as the difficulty involves the calculation of torsional properties including warping constant. (W-shape with Cap channel) or SC (S-shape with Cap Channel) girders. They provide only the approximate formulas which were derived from singly symmetric I-sections.
Crane runway beam with channel cap on W-beam
Crane runway beam with channel cap on W-beam
I am trying to select an appropriate W-beam and channel cap for a runway beam that is to support an under running bridge crane. The channel cap is to be on top of the W-beam. I am using the AISC ASD code and I am having problems with what value to use for 'bf' in formula F1-2. Would 'bf' be the width of the channel flange or the width of the W-beam flange? Am I correct in assuming that 'Af' in that formula would be the sum of the area of one flange of the W-beam and the area of the web of the channel.Also in section B.5.1, on the check for compact or non-compact section, b/t is compared to 65/sqrt(Fy). What value of 'b' & 't' should be used in this case with the composite section?
Thanks in advance for any help with this problem.
Tony Billeaud
Mechanical Engineer
Mechanical Engineer