Engineering Mechanics

(^266) „„„„„ A Textbook of Engineering Mechanics
Similarly, taking moments about the joint B and equating the same,
PCD × 4 = (5 × 8) – (PCE × 2) = 40 – (10 × 2) = 20
∴
20
5 kN (Compession)
CD 4
P ==
and now taking moments about the joint C and equating the same,
PBD × 2 = 5 × 4 = 20
∴
20
10 kN (Tension)
BD 2
P ==
Example 13.10. A pin-joined cantilever frame is hinged to a vertical wall at A and E and is
loaded as shown in Fig 13.35.
Fig. 13.35.
Determine the forces in the members CD, CG and FG.
Solution. First of all, extend the lines through the joints B, C and D as E, F and G meeting at
O. Through G, draw GP perpendicular to CD. Similarly, through C, draw CQ perpendicular to FG.
Now extend the line of action of the member CG, and through O, draw a perpendicular to this
line meeting at R as shown in Fig. 13.36.
Fig. 13.36.