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Thermal Stress (Thermodynamics)

  1. Sep 20, 2009 #1
    1. Equation F/A=-Y[tex]\alpha[/tex][tex]\Delta[/tex]T (thermal stress) gives the stress required to keep the length of a rod constant as its temperature changes. Show that if the length is permitted to change by an amount [tex]\Delta[/tex]L when its temperature changes by [tex]\Delta[/tex]T, the stress is equal to F/A = Y(([tex]\Delta[/tex]L/L[tex]_{}0[/tex])-[tex]\alpha\Delta[/tex]T) where F is the tension on the rod, L(naut) is the original length of the rod, A its cross-sectional area, alpha its coefficient of linear expansion, and Y its Young's modulus.

    i don't know where to start can somebody help? this thermal stress is stressing me out
    Last edited: Sep 20, 2009
  2. jcsd
  3. Sep 20, 2009 #2
    please help any feedback im begging you
  4. Sep 20, 2009 #3

    Andrew Mason

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    If the length changes by dL what does the volume change by? So what does the area, A, change by? How does this affect the stress, F/A?

  5. Sep 20, 2009 #4

    if the length changes the area would increase and the pressure would decrease. i'm not sure how you "Show This" though
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