1.16 A composite bar of 20 mm X 20 mm cross-section is made up of three flat bars as shown in Fig. 1.74. All the three bars are rigidly connected at the ends when the temperature is 20C. Determine (i) the stresses developed in each bar when the temperature of the composite bar is raised to 60C STEEL 8mm 20 mm ALUMINIUM 4 mm STEEL 8 mm -20 mm- Fig. 1.74 (ii) the final stresses in each bar when a load of 17.6 kN is applied to the composite bar E = 80 GPa E = 200 GPa a = 11 x 10-/C a = 22 x 10-6/C