Question

Maximum force in member GB of the bridge truss shown below for a point load of $50kN$ moving on the bridge will be ...... $kN$

• A. 35.35

Answer 1

The correct option is A 35.35
When unit load is at A,
$F_{GB}=0$
When unit load is at E,
$F_{GB}=0$
When unit load is at B,
$R_A=0.75kN,R_E=0.25$
$F_{GB}=0.25\sqrt{2}=0.354$ (Tension)



When unit load is at C
$F_{GB}=0.5\sqrt{2}=0.707$ (Compressive)



Hence, ILD for $F_{GB}$ is shown below



Maximum force in member GB due to a point load of 50 kN
$=0.707\times 50=35.35kN$