Engineering Optimization: Theory and Practice, Fourth Edition

7.22 Test Problems 469

Figure 7.22 A 25-bar space truss [7.38].

=sum of deflections of nodes 1 and 2

f 3 ( X)=−ω 1 = egative of fundamental natural frequency of vibrationn

whereδix= eflection of noded ialongxdirection.

Table 7.7 Loads Acting on the 25-Bar Truss

Joint

1 2 3 6

Load condition 1, loads in pounds

Fx 0 0 0 0
Fy 20,000 −20,000 0 0
Fz −5,000 −5,000 0 0

Load condition 2, loads in pounds

Fx 1,000 0 500 500
Fy 10,000 10,000 0 0
Fz −5,000 −5,000 0 0