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Homework Help: Thermal stress of two peices of metal attacthed to two plates.

  1. Jan 30, 2013 #1
    1. The problem statement, all variables and given/known data
    2)Both, a brass tube and the steel rod located inside the brass tube are solidly attached to common end plates A and B at either end.
    The respective diameters are :

    Do = 5.4 [cm]
    Di = 3.0 [cm]
    d= 2.8[cm]
    alpha=19x10^-6/degree celcius
    alpha=12x10^-6/degree celcius
    Initially the assembly is stress free.
    Now the temperature increases simultaneously for the brass tube and steel rod by 58oC. As a result the distance L between the two end plates will change.
    Determine the resulting stresses in the brass tube and the steel rod, counting tension as positive and compression as negative.

    Following Questions to be answered:
    Stress in Brass in MPa
    Stress in Steel in MPa

    2. Relevant equations

    3. The attempt at a solution
    I solved for L in the equation above since the length is the same. then I pluged the know values in them but now I have a sigma on both sides and that is what I need to find out and I cant figure out how to solve it.
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Jan 30, 2013 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    It's not clear, but is the distance between the plates supposed to remain constant after the temperature change?
  4. Jan 30, 2013 #3
    Yes but that distance is not given, the plates move a distance delta L apart after the tempature change.
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