CMAA 74 overhead hoist design 2

[djs017]

I'm working on developing a spreadsheet based on CMAA 74 to design overhead hoists and monorails. The design procedure seems pretty straight forward, but I can't seem to find allowable bending stress. My question is, should I follow AISC guidelines for this? My plan was to analyze a few structures based on AISC and then analyze them based on CMAA and compare the results. But it seems I will be also using some AISC in my CMAA spreadsheet (although much of CMAA is taken directly from AISC). Any advice is appreciated!

 

[SJBombero]

The allowables should be in Table 3.4-1.

 

[djs017]

so are the allowable compression and tension stresses used as allowable bending stress?

 

[weab]

djs,
In the typical monorail, there is no significant tension or compression except for tractive forces. Though CMAA74 may not say it (I don't have the code with me), the intent is referring to flexural bending and flexural compression. That is the primary loading on all monorails whether you talking about tension in the bottom flange due to overall beam bending or about localized flange bending.

 

[SJBombero]

Flexural bending does cause a tension and compression stresses. The limits in table 3.4-1 would apply, except for the top flange, assuming positive moment, which would also be subject to the stricter compression limit of 3.5.6. When the bottom flange is analyzed for local bending, there will be a combination of compression and tension stresses which would then be subject to the limits in Table 3.4-1.