Question Two: (@) Derive an expression for the radius of curvature, r, of a bi-metallic strip of rectangular cross-section made by joining strips of brass and steel of the same length, L. The strips have the same thickness, h, and breadth, b. The assembly is heated through a temperature rise, T. Note that the coefficient of thermal expansion of brass is higher than that of steel. (15 marks)
(b) A bi-metallic strip similar to the one described in part (@) is 300 mm long, while each strip is 2 mm thick. The strip is initially straight and rests on a flat surface with the steel uppermost. Determine the maximum clearance between the strip and the surface following a temperature rise of 80°C. Take brass = 1.9 x 10^-5/°C; asteel = 1.1 x 10^-5/°C; Ebrass = 105 GPa; Esteel = 200 GPa.