Example 233

The 11-storey unbraced frame shown in Figure 23.13 is analyzed using the second-order elastic analysis approach presented earlier, with the intention to illustrate frame behavior due to the interaction of second-order effects and the semirigid behavior of the beam-to-column connections. All of the beam-to-column connections of the frame are assumed to be identical.

In order to trace the effect of semirigid behavior on geometric second-order effects, nine (9) analyses were conducted for the frame with the end-fixity factor decreasing in decrements of 0.1 from that for a rigid connection (r = 1.0) to that for a flexible connection (r = 0.2). The frame was analyzed with and without considering second-order effects for each case. The lateral deflection obtained at the roof level for each case is presented in Table 23.7 along with the values of the end-fixity factor, the corresponding w1 = 59.45 kN/m; w2 = 74.14 kN/m All beams W530 x 123

kN

0 0

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