Length of each member of truss is 2 m. Members AB and CD are subjected to a temperature rise of 20°C and coefficient of thermal expansion is 12×(10−6)/°C. Then vertical deflection at joint E will be (in mm)
δE=ΣK(LαΔT)...(1)
At joint A; ΣFy=0
⇒0.5−KABsin60∘=0
∴KAB=1√3(compressive)
Also; kAB=KCD(Duetosymmetry)
From (1)
∴δE=(1√3×2×12×10−6×20)×2m=0.55mm