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Dimensioning of hollow square and circular rod

  1. Mar 31, 2014 #1

    Can someone tell me how to determine dimensions for a square hollow rod and circular hollow rod when the material and maximum load is known?
  2. jcsd
  3. Mar 31, 2014 #2


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    This will depend on the way the load is applied to the hollow member.
    Is it axial compression or tension, torque or a sideways deflection ?
    There is also a trade-off between outer dimension and wall thickness.
  4. Apr 1, 2014 #3
    The applied load is compression and there is also bending.
    It´s a telescopic rod with the circular rod inside the square rod and it´s standing vertically with an angle. The rod has to support a boat standing in a boat rack so it has to support the weight of the boat and the force from wind gust. The material is set to be S235JR Low Carbon Steel.
    I hope you can help. Thanks.

    http://imagizer.imageshack.us/v2/1024x768q90/833/drpm.jpg [Broken]
    Last edited by a moderator: May 6, 2017
  5. Apr 5, 2014 #4


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    JohnnyR: If the length of your telescopic rod assembly is 2,26 m, and if your member forces in post 3 are correct, then it currently appears the round tube would need to have cross-sectional dimensions (outside diameter by wall thickness) as listed in any of the following options.

    (1) 216 x 5 mm
    (2) 197 x 6
    (3) 182 x 7
    (4) 171 x 8
    (5) 155 x 10​
    Last edited: Apr 5, 2014
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