how to design a beam with handrail attached to top ?

[donnabean]

Hi there,

I am working on a beam with handrail on top of it, I think I may need to consider torsion, but how much I shall consider? Any other issue I should pay attention to?
Thanks.

 

[BAretired]

If you have a handrail on top of a beam, you must also have a floor which is supported by the beam. Why not use the floor framing to resist the required moment from the handrail?

BA

 

[msquared48]

True.

The floor diaphragm could take one component of the torsional force and the transverse floor joists or intermediate blocking the other.

Mike McCann
MMC Engineering

 

[JedClampett]

Or you could get Design Guide 9: Torsional Analysis of Structural Steel Members

http://www.aisc.org/store/p-1585-de...analysis-of-structural-steel-members-see.aspx

from AISC and follow the methods included. After I did a few of those, I really felt like a structural engineer.
An approximate conservative method is to convert the torsion into a couple the depth of the section and apply the resulting horizontal loads to create weak axis bending. Check the moment over half of Sy.
And don't forget that the torsional load needs to go out through the connection(s).

 

[KootK]

As for how much, you're building code will have guidelines as to how much load should be applied to guards and handrails. Those loads multiplied by their heights of application will give you the moments that will need to be resisted either by torsion in your beam or moment in the adjacent floor system.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.