A steel flat bar of dimensions 4x1x12 inches is PINNED between two copper bars of dimensions 4x2x12 inches at room temp. The PINNED assembly is then cooled by 200 degrees fahrenheit. At that temp calculate the following knowing that Ecopper=10.6E3 ksi, Esteel=30E3 ksi, Coeficient of thermal expansion for copper= 13E-6/degree fahrenheit, and the coeficient of thermal expansion for steel = 6.5E-6/degree fahrenheit.
a. Calculate the axial stress in the steel.
b. Calculate the axial stress in the copper.