Engineering Mechanics

(^302) „„„„„ A Textbook of Engineering Mechanics

2. Figure 14.20 shows a framed structure of 5 m span. The structure carries vertical loads as
   shown in the figure. Find the forces in the members of the structure and tabulate the results.
   Ans. AB = 1.2 kN (Compression)
   BC = 0.6 kN (Compression)
   CD = 2.0 kN (Compression)
   AC = 0.5 kN (Compression)
   AD = 1.0 kN (Tension)


3. A pin-jointed frame is supported at F and E and loaded as shown in Fig. 14.21. Find the
   forces in all the members of the frame and state in each case, whether the member is in tension or
   compression.
   Ans. AF = 16.7 kN (Tension)
   FE = 8.0 kN (Tension)
   ED = 10.0 kN (Tenison)
   AB = 13.3 kN (Compression)
   BF = 3.0 kN (Tension)
   BC = 13.3 kN (Compression)
   FC = 6.7 kN (Tension)
   EC = 1.0 kN (Compression)
   CD = 8.0 kN (Compression)


4. A pin-jointed truss is subjected to three points loads at A, B and C as shown in Fig. 14.22.
   Find by any method, the forces in all the members of the truss.
   Ans. AB = 1.25 kN (Tension)
   BC = 1.6 kN (Compression)
   CD = 2.0 kN (Compression)
   AF = 0.75 kN (Compression)
   BF = 4.8 kN (Compression)
   FE = 0.75 kN (Compression)
   BE = 3.0 kN (Tension)
   CE = 1.2 kN (Tension)
   ED = 1.6 kN (Tension)

14.7. CANTILEVER TRUSSES

We have already discussed that a truss which is connected to walls or columns etc., at one end,

and free at the other is known as a cantilever truss. In the previous articles, we have noticed that the

determination of the support reactions was absolutely necessary to draw a vector diagram.

But in the case of cantilever trusses, determination of support is not essential, as we can start

the construction of vector diagram from the free end. In fact this procedure, actually gives us the

reactions at the connected ends of the truss.

Fig. 14.20.

Fig. 14.21.

Fig. 14.22.