Torsion of top flange restrained monorail beam
Torsion of top flange restrained monorail beam
(OP)
What is the way to consider a torsion of monorail beam when the concentrated lateral load is applied to bottom flange and only the top flange is supported. The beam is for monorail so stiffeners can't be added.






RE: Torsion of top flange restrained monorail beam
If there's any chance that the load will be deliberately swinging, lifted off center, or otherwise have deliberate lateral and torsional loads put on the monorail then I would consider a deeper beam so that you can use partial depth stiffeners. It doesn't take much for a millwrong to overload a monorail by side loading.
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries
www.americanconcrete.com
RE: Torsion of top flange restrained monorail beam
"The lateral force on crane runway beams with electrically powered trolleys shall be calculated as 20 percent of the sum of the rated capacity of the crane and the weight of the hoist and trolley. The lateral force shall be assumed to act horizontally at the traction surface of a runway beam, in either direction perpendicular to the beam, and shall be distributed with due regard to the lateral stiffness of the runway beam and supporting structure."
The strength of the monorail beam can be approximately checked this way
Mx/Sx+My/Sy,t <= allowable stress
Mx/Sx+My/Sy,c <= allowable stress
Mx is vertical bending moment
My is lateral bending moment
Sx, section modulus of the beam along x-x
Sy,t section modulus of the beam tension part along y-y
Sy,c section modulus of the beam compression part along y-y
RE: Torsion of top flange restrained monorail beam
http://www.eng-tips.com/viewthread.cfm?qid=93822