To give you a better idea, I have it drawn out here: http://tinypic.com/r/eq6ln5/6(adsbygoogle = window.adsbygoogle || []).push({});

I am calling the thickness of a rod t and the thickness of the shaft t2. I am using the basic equation Ixx = (integrate over area)(y^2)dA on different sections and then adding them all together, following the guidelines of this website:

http://www.brighthubengineering.com...-inertia-of-irregular-sections-in-five-steps/

I split the shaft into sections, as follows: http://tinypic.com/r/2j5mc8l/6

I calculated the moment of inertia of each section and added them together.

Referring to half of one rod (aka half of the inner diameter) as L, I have come up with this equation:

=2*L^3*(SQRT(2)/2)^3(three rods)

+2*(t*L*(1-(SQRT(2)/2)))(top of center rod)

+L*t^3/12(middle horizontal rod)

+(PI()/4)*((L+t2)^4-(L)^4)(hollow cylinder)

Am I going about this the correct way? Any suggestions would be appreciated.

Thank you!

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# How do you calculate the moment of inertia for a hollow shaft with a truss-like struc

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