Good morning PF, I am having some difficulty finding info on calculating a composite moment of inertia. The section I am working with is 8 separate columns (WT5x15) arranged evenly spaced around the circumference of a circle. You can see what i'm taking about in the attached jpg. I found that the moment of inertia of each column is 9.28 in^4, is the total moment of inertia just the sum of each column or does their arrangement factor in also? Thank you.