Engineering Mechanics

Chapter 14 : Analysis of Perfect Frames (Graphical Method) „„„„„ 305

Example 14.11. A truss shown in Fig. 14.27 is carrying point load of 5 kN at E.

Fig. 14.27.

Find graphically, or otherwise, the forces in all the members of the truss and indicate results
in a tabular form.

Solution. First of all, draw the space diagram and name all the various members according to
Bow’s notations as shown in Fig. 14.28 (a).

Fig. 14.28.
Now draw the vector diagram as shown in Fig. 14.28 (b), starting from the joint E. Measuring
the various sides of the vector diagram, the results are tabulated here :

No. Member Magnitude of force in kN Nature of force

1 CE (1-3) 10 Tension

2 DE (2-3) 11.2 Compression

3 CD (4-3) 5.0 Tension

4 BD (2-4) 10 Compression

5 BC (4-5) 0 —

6 AC (1-5) 11.2 Tension