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Complicated Moment of Inertia Calc

Hoping somebody can help me solve this.

I'm trying to figure out how to calculate the moment of inertia of a particular section of a rotational body that is made up of several parts of varying size/density.

I have all of the variables, and I know how to calculate the I of an individual piece, but not the total effect on the system. I have attached an image that lays out an example of the problem.

In the image, I have the actual answer as calculated by solidworks, but I need to know how it's getting the answer for Ixx for each part.

The total system Ixx = 27750.56 which is the sum of the Ixx for each section, trying to figure out how to calculate that given the other known variables.

Any help would be greatly appreciated: Image

[IMG]http://www.engineersedge.com/engineering-forum/attachment.php?attachmentid=1222&stc=1[/IMG]

Thanks,

Kyle