Using the stiffness method, evaluate the reactions for the structure illustrated below, which is subjected to a linear temperature change over the cross-sections defined by top and bottom variations...

Using the stiffness method, evaluate the reactions for the structure illustrated below, which is subjected to a linear temperature change over the cross-sections defined by top and bottom variations of: ΔT1 = 20°C and ΔT2 = 10°C (as shown). The temperature changes are constant over the length of each element. The crosssection is doubly-symmetric and is 0.3 m deep. Adopt I = 240 × 106 mm4, A = 8 × 103 mm2, E = 200 GPa and α = 11 × 10−6/°C.