Monorail Lower Flange Bending 1

[sda97]

The 2004 CMAA 74 has some formulas for calculating lower flange bending stresses in monrail beams. Are these formulas correct? A previous Eng-Tip (2/6/03) indicated that there may be errors in the formulas. CMAA 74 does not give any theory behind the formulas. I have a old ACCO Chain and Lifting Data pamphlet that has allowable lower flange loadings for S nd W shapes but they do give any theory either. I did find an AISC Steel Interchange question/answer dealing with this topic that gave at least some basis for there analysis. All formulas give some high flange bending stress which seriously reduce the capacity of a monorail beam. I know the CMAA is aimed at cranes and not hoist or monorail beams. Does anyone have an thoughts on this subject? sda97

 

[ehcet]

The CMAA specs. is a copy of the original FEM-DIN (European)
specification. The research was done by Mannesmann Demag
(Crane manufacturer) in Germany many years ago.
Try to get hold of DIN (German Industry Norm) or FEM specs, but you will not find to much details.
I used this formulas for which I received training in Germany,(Working for Demag over 35 years here in Canada).
The method is excepted all over the world.You do not have to worry about how they arrived to the formulas.
CMAA will not give you any details because they do not know
themselves.If you have any other question regarding this subject or overhead crane and runway design, contact me at
ehcet@idirect.com
Good luck
Ernie