A structural system consists of three joined bars of different materials and geometries, as shown in Fig. 1-31. Bar O is aluminum alloy, bar 2 is cold rolled brass, and bar O is tempered alloy steel. Properties and dimensions of all three are shown in the figure. Initially, the entire system is free of stresses, but then the right support is moved 3 mm to the right whereas the left support remains fixed in space. Determine the stress in cach bar due to this 3 mm displacement. Ans. o, = 223 MPa 0, = 178 MPa o, = 446 MPa A-4 x 10 m E, = 70 GPa A-5 x 10m? E, - 105 GPa A,-2 x 10m E, - 200 GPa L,-0.5 m Ly- 0.3 m L,-0.4 m Fig. 1-31 INI