I have a few simple questions regarding beam design:
My structural model description is the following:
I have a simple monorail that is suspended from the perpendicular floor beams above. The connections from the top of the monorail to the underside of the bottom flange of the floor beams are welded all around and I have them defined as fixed (these connections are 6" HSS) aka, rigid links. This connection arrangement will produce braced lengths of the top flange of the monorail beam. The monorail is 30'-0" in length, including a 2'-0" cantilever, with top flange rigid connections at 5'-0" o.c.
For defining the design parameters for this beam, should I specify Lz, Lz, Lx, if the beam carries gravity loads only? Correct me if I am wrong but these parameters are for defining axial compression, correct? I ask because when I do, I receive a Utilization that is greater than my hand calcs. and the "Clause" for governing case is AISC H-3, which is in regards to flexure & compression about the major axis. Should this be checked or is this beam parameter discrediting the actual capacity of the monorail due to flexural loading only? I am trying to determine accurate analysis, not conservative. Either case, I need to have a clear understanding on whether Ly, Lz, and Lx need to be defined for beam analysis AND if they refer to the axis ABOUT which the bending occurs (i.e. if a beam deflects downward with the major axis as the vertical axis and being braced vertically at the midpoint then Lz would be defined as L/2, correct, not Ly? I do have UNT and UNB defined accordingly. Do I need to define MAIN 1 for members to check slenderness as well? And Please see input below...
PARAMETER 1
CODE AISC
FYLD 36000 MEMB 195 197 TO 199 203 TO 206
FU 58000 MEMB 195 197 TO 199 203 TO 206
*
DMAX 24 MEMB 195 197 TO 199 203 TO 206
DFF 480 MEMB 195 197 TO 199 203 TO 206
NSF 1 MEMB 195 197 TO 199 203 TO 206
RATIO 0.9 MEMB 195 197 TO 199 203 TO 206
CB 1 MEMB 195 197 TO 199 203 TO 206
WELD 1 MEMB 195 197 TO 199 203 TO 206
BEAM 1 MEMB 195 197 TO 199 203 TO 206
TAPER 1 MEMB 195 197 TO 199 203 TO 206
*
DJ1 59 MEMB 195 197 TO 199 203 TO 206
DJ2 58 MEMB 195 197 TO 199 203 TO 206
LY 351 MEMB 195 197 TO 199 203 TO 206
LZ 60 MEMB 195 197 TO 199 203 TO 206
LX 60 MEMB 195 197 TO 199 203 TO 206
UNT 60 MEMB 195 197 198 203 TO 206
UNB 351 MEMB 195 197 TO 199 203 TO 206
CAN 1 MEMB 199
UNT 24 MEMB 199
CHECK CODE MEMB 195 197 TO 199 203 TO 206
Also,
If I have a beam (monorail), which I need to design to hoist a load and transport it down the length of the beam; can STAAD Pro V8i effective analyze this beam for this type of moving load? Can Bentley please furnish a procedure for correctly defining this in for AISC_US using an arbitrary load and length?
Thanks in advance!
