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Homework Help: Poisson's ratio

  1. Aug 6, 2005 #1
    can anybody please tell me how this equation has been arrived?

    dA=A(1-m dL/L)^2 -A

    A=Area of cross section
  2. jcsd
  3. Aug 6, 2005 #2
    Whithin what context did you acquire this equation ?

  4. Aug 6, 2005 #3


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    What is m?

    Looks to me it's a formula for calculating the % change in cross-sectional area for a % stretch lengthwise. Cross-section area is a function of the width (or perhaps width x length). But width is compressed as length is stretcehd and that has to be taken into account while calculating the change in area.

    Having written all this, I don't get why a squared term is involved, because while the calculation of an area may involve a square, the change in such an area would be linear.

    From a Yahoo search on "Poisson's ratio":
    http://www.millersv.edu/~jdooley/macro/derive/elas1/poissn/poissn.htm [Broken]
    Last edited by a moderator: May 2, 2017
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