Question

Influence line diagram for force in a member of truss is shown in the figure below:



A dead load of truss is 10 kN/m and live load is 5 kN/m, live load is longer than span. Maximum tensile force in the member is _________ kN.

• A. 15

Answer 1

The correct option is A 15
$TensileforceduetoDL=10\times [\frac{1}{2}\times 1\times 4-\frac{1}{2}\times 0.5\times 6]=5kN$

To obtain maximum tensile force, live load should be placed over the tension part only.

$MaximumtensileduetoLL=(\frac{1}{2}\times 4\times 1)\times 5=10kN$

$\therefore$ Maximum tensile force = 5 + 10 = 15 kN.