A steel tube 30mm external diameter and 25mm internal diameter encloses a gun metal
rod 20mm diameter to which it is rigidly joined at each end. The temperature of the
whole assembly is raised to 150ºC. Find the intensity of stress in the rod when the
common temperature has fallen to 20ºC. The value of the Young’s modulus for steel and
gun metal are 2.1 × 105 N/mm2
respectively. The coefficient of linear expansion for steel
is 12 × 10-6
/ºC and for gun metal is 20 × 10-6
/ºC.
