How to calculate rz for single angles

[avalonlane]

I'm working on a mathcad sheet that will calculate all the shape properties just by typing in the leg sizes and the thickness. It'd help with saving time if I didn't have to look up and type out all the properties. I've got most of the properties worked out, just not anything to do with the z-axis.

Specifically, I haven't been able to find out where or how they calculate the rz value.

ex. L6x4x3/4 --> rz = 0.856"

 

[jnadeau]

avalonlane,

rz=sqrt(Iz/A) where Iz is the minimum moment of inertia and A is the cross sectional area. Iz can be calculated from Ix, Iy, and Ixy using Mohr's Circle if x and y are centroidal axes of the cross section.

Note that the section properties you compute will approximate the values tabulated in the shape tables (as I assume that you are not modeling the fillets).

 

[JAE]

Also...

AISC has excel spreadsheet tables of all the shape properties, including rz, that you could simply load in to your mathcad sheet.

I think they are either free, or very inexpensive.

 

[KBVT]

Try here for AISC members .....

http://www.aisc.org/Content/Navigat...AISC_Shapes_Database/AISC_Shapes_Database.htm