Question: 135 the rigid bar ac is pinned at a and...

1.35. The rigid bar AC is pinned at A and attached to bars DB and CE as shown in Fig. 1-32. The weight of AC is 50 kN and the weights of the other two bars are negligible. Consider the temperature of both bars DB and CE to be raised 35°C. Find the resulting normal stresses in these two bars. DB is copper for which E = 90 GPa, α = 18 × 10^–6/°C, and the cross-sectional area is 1000 mm², while CE is steel for which E = 200 GPa, α = 12 × 10^–6/°C, and the cross section is 500 mm². Neglect any possibility of lateral buckling of the bars.    Ans. σ_st = 72 MPa, σ_cu = –21.7 MPa