At a temperature of 5°C, a 3-mm gap exists between two polymer bars and a rigid support, as shown. Bar (1) is 50-mm wide and 20-mm thick [E = 800 MPa, α = 140 × 106/°C]. Bar (2) is 75-mm wide and 25-mm thick [E = 2.7 GPa, α = 67 × 106/°C] bar. The supports at A and C are rigid. Determine: (a) The lowest temperature at which the 3-mm gap is closed. (b) The normal stress in the two bars at a temperature of 60°C. (c) The normal strain in the two bars at 60°C. 3-mm gap 50 mm 75 mm (1) (2) B A 700 mm 400 mm Ans: a) 29°C, b) 4.05 MPa (C), 2.16 MPa (C) c) 2.64, 2.88