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Interpreting the Second Moment of Area and Euler's Formula Values

  1. Nov 3, 2018 #1
    Hi all

    I was hoping someone could remove some doubt in my mind with regards to interpreting the Second Moment Of Area and Eulers formula for buckling.

    Am I correct in thinking that:-
    - The higher the Second Moment Of Area Value the more resistant to bending.
    - The lower the Second Moment Of Area Value the less resistant to bending.

    Using Eulers formula for buckling I have calculated the critical load for a column in the X and Y axis, my values are:-

    Ix = 25.39N
    Iy = 634N

    Am I correct in interpreting these results as the column will buck in the x axis first because it will only take 25.39N of load before it buckles - is this correct?

    I can do the math it is the concept I struggle with (doesn't help that I have a crap tutor).

    thank you.
     
  2. jcsd
  3. Nov 3, 2018 #2

    PhanthomJay

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    Buckling is a function of Young’s modulus, E, Boundary conditions , column length , and the Moment of inertia, I. For 2 columns of the same material and length and support conditions, the one with the smaller I will have a lower critical buckling load, as one might expect. Although a column bends when it buckles, I’d use the term “resistance to buckling “ rather than “resistance to bending “.Note that a perfectly straight ideal column with a compressive load applied axially will never buckle; there must be a slight initial deformation or eccentric load before it does. Also, if it is below a certain length, it will crush and fail before it ever buckles.
    yes, correct, provided that the column is not restrained in that direction.
     
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