ABSTRACT
A supported steel 20-span space truss is shown in Figure 1. It is 8 m long with the height of 0.9 m, width of 0.56 m, and consists of 312 bars, with the nodes of 108. The young’s modulus is 2.06 Gpa, and the density is 7850 kg/m3. The bars, steel tubes, are connected by bolted spherical joint (bottom right in Figure 1). The bars are classified into three types according to its radius.
