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another beam statics ?  
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Posted by: docntye ^{®} 11/17/2004, 19:27:21 Author Profile Mail author Edit 
Hey you all. Im trying to calculate moment of inertia for a piece of hollow 2 x 2 square inch tubing, 1/8" wall. Its being treated as a simple supported beam in the instance with a distributed load. Can I still use I=(bh^3)/12. Any help would be appreciated. Thanks 
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Re: another beam statics ?  
Re: another beam statics ?  docntye  Post Reply  Top of thread  Forum 
Posted by: docntye ^{®} 11/18/2004, 18:39:43 Author Profile Mail author Edit 
Im not understanding what it means when it asks for,"distance to neutral axis/plane z" on the beam calculators?
Thanks 
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Re: another beam statics ?  
Re: another beam statics ?  docntye  Post Reply  Top of thread  Forum 
Posted by: Cragyon ^{®} 11/18/2004, 10:19:57 Author Profile Mail author Edit 
I believe the eqaution is I=(A^4  B^4)/12 where H = heigth outside and B = heigth inside. or I=(bh^3)/12  (bh^3)/12 or bh outside  bh inside They have a calculator here at /calculators/section_square_case_4.htm
Modified by Cragyon at Thu, Nov 18, 2004, 10:26:17 
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Re: another beam statics ?  
Re: Re: another beam statics ?  Cragyon  Post Reply  Top of thread  Forum 
Posted by: devitg ^{®} 11/18/2004, 22:13:20 Author Profile Mail author Edit 
Inertia moment of the rectangular shape is b * h^3 /12 , where [b] is the size perpendicular to the load and [h] the size colinear with the load , when the shape is hollow you have to substrac the hole from the whole So for a square wher both size are the same a=b=h I moment = a * a^3/12 =a^4/12 About the distance from the neutral axis , in this case is a/2. this distance is used to calc what is call the resistent module [W]

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