Question

A cantilever truss is loaded and supported as shown in fig. Find the value of P, which would produce an axial force of magnitude 3KN in the member AC.

Answer 1

Let us assume that the forces is find out in the member AC, DC and DF

Let

T1 = Force in the member AC

T2 = Force in the member DC

T3 = Force in the member DF

Draw a section line, which cut the member AC, DC, and DF.

Consider right portion of the truss, because Force P is in the right portion. Taking moment about point D,

∑MD = 0

T1 X AB + P X (AC – AD) + P X (AE – AD) = 0

-3 X 2 + P X 1.5 + P X 4.5 = 0

P = 1KN