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Derivation of this equation:

  1. Nov 14, 2012 #1
    Equation attached.

    For those who cant see the image here it is in text form, k=(Gd^4)/(8D^3 n )

    It is the equation for the stiffness of a spring in terms of its dimensions:

    G - shear constant
    d - wire diameter
    D - coil average diameter
    n - number of active coils (total coils -2 as the top and bottom coils are not considered active)

    I would like to know how to derive this equation as it is a big chunk of my project,

    I am doing this as part of a university project, and your derivation will be duly noted/referenced.

    Thanks in advance!


    Attached Files:

  2. jcsd
  3. Nov 14, 2012 #2
    Since you are at university, why can you not look this up for yourself in a mechanics of materials text in the library?

    For instance page 82 - 83 of


    Strength of Materials



    Mechanics of Materials p299 to 301
  4. Nov 14, 2012 #3
    I'll do that now, thank you for the book!
  5. Nov 14, 2012 #4
  6. Nov 14, 2012 #5
    yeah! i found that post very helpful for understanding the concept, jheez, i love this stuff, i wish i could have the time in the day to learn it all, along with everything else i want to do :( anyway! thank you very much! best first post ever i think!
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