Question

A commonly used method of fastening one part to another part is called "shrink fitting." A steel rod has a diameter of 2.0020 cm, and a flat plate contains a hole whose diameter is 2.0000 cm. The rod is cooled so that it just fits into the hole. When the rod warms up, the enormous thermal stress exerted by the plate holds the rod securely to the plate. By how many Celsius degrees should the rod be cooled? (See Table 12.1 for appropriate constants.)

Answer 1

Coefficient of linear expansion of steel =12x10^-6 /oC

do = =2.002 cm

d = 2 - 2.002 = -0.002 cm

= d/do(T)

T =d/do* = -(0.002)/(2.002x12x10^-6)

T = - 83 ⁰C