Chapter 2
Q. 2.2
Determine the forces produced by the applied loads in members 46, 56 and 57 of the sawtooth truss shown in Figure 2.11.
Step-by-Step
Verified Solution
The support reactions are calculated and the truss cut at section A-A as shown. The directions of the member forces on the right-hand free body diagram are assumed as indicated in (ii).
Taking moments about node 7 gives the force in member 56 as:
\begin{aligned}P_{56} &=0 / 6.93 \\&=0\end{aligned}Taking moments about node 5 gives the force in member 46 as:
\begin{aligned}P_{46} &=8 V_{7} / 4 \\&=8 \times 10 / 4 \\&=20 \text { kips … compression }\end{aligned}Taking moments about node 6 gives the force in member 57 as:
\begin{aligned}P_{57} &=6 V_{7} / 3.46 \\&=6 \times 10 / 3.46 \\&=17.32 \text { kips … tension }\end{aligned}