# How to Find CG, MI, Ztop and Zbottom of the I section shown below?

Discussion in 'Boat Design' started by zalads, Jul 23, 2009.

1. Joined: Jul 2009
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Please explaing me how to find CG, MI, Ztop and Zbottom of the I section shown as attached here with.

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2. Joined: Oct 2008
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Location: Japan

Have you begun to study basic structures yet?

3. Joined: Jul 2009
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Location: Surat, India

Yes, just started my studies can u pls advise me how to do this

4. Joined: Oct 2008
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Location: Japan

Well first, you need to start a table with seven columns with these headings:

item, area (a), lever (h), ah, ah^2, k^2, ak^2

Then find the area, the lever of each item about a fix datum. Then calculate the 2nd moment of area for each item and finally its own inertia about its own axis. Add up the columns and by parallel axis theorem move the axis from assumed datum to the neutral axis.

If this does not make sense, then you require much more reading before advising further.

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### GreybarnJunior Member

This is a second year of college level engineering problem. What year are you in your studies?

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### gonzoSenior Member

Is the material homogenous?

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### YellowjacketSenior Member

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