Anyone know how to calculate second moment of area for a fabricated column such as this one below. Its made from 2 standard channels welded together

api column

how accurate does it need to be ?

if you don't mind ignoring the radii then you can easily use parallel axis theorem on each of the rectangular bits...


[edit]
this video gives you the idea:


[Edited on 5/11/2013 by mcerd1]

Easy way? Sketch it in Solidworks or other 3d modelling software and have a look at the section properties and it will tell you

As they are drawn in the pic you can calculate for each of the shapes and then add the results to obtain the second moment of area for the assembly.

do you have the sizes of the 2 channel sections ?