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I section vs square section

  1. May 8, 2012 #1
    Dear all

    Apart from cost saving (or reduction in material)what is the technical advantage using I section instead of square section?

    My application is,section is going to be simply supported to the static load.myself awared that I section is good for bending loads.Instead i am using square section,so my area moment of inertia will be high,the bending stress would be low.

    Kindly comment the above subject.

  2. jcsd
  3. May 9, 2012 #2
    I use square sections when I want a cleaner or more attractive design, or when I have a bending component in the other plan. Less surface area collects less dust and is easier to wash down. When galvanizing less surface area uses less and is easier to ensure a uniform coating.
  4. May 9, 2012 #3


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    Science Advisor

    The most important reason to use an "I beam" (or "I section") is that it has much less volume and so much less weight than a square section of the same dimensions. And, since such things as "bending moment" depend upon the length in varying directions rather than volume, you don't lose strength.
  5. May 9, 2012 #4
    I beam definitely is an obvious choice for situations where bending moment is of prime concern. As long as following conditions are not true, you can always go for I-beam:

    1: Manufacturing: Normally i beams are not available in smaller section and hard to join (welding etc)

    2: I beam is a poor choice where you have loads acting transversely to the length of beam.
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