224
NONLINEAR ANALYSIS OF PLANAR STEEL FRAMES Pt
Pb
Pb
Pt
H Pb
Pb
Pb
Pb
H
H
250
500
250
Figure 13.5 Loads on the frame tested
H
H 0.6
0.6
0.5
0.5
0.4
0.4
Specimen 1
0.3
Pt = 5.0 kN
0.2
0
2
3
4
5
6
H
Pt = 0 kN
0.2
Pb=1.5 kN
0.1
Specimen 1
0.3
Pb=1.8 kN
0.1 u (cm)
0
1
2
3
4
5
6
u (cm)
0.6 0.5 0.4
Specimen 1
0.3 0.2
Predicted
Pb=1.8 kN
0.1 0
Measured
Pt = 7.0 kN
1
2
3
4
5
6
u (cm)
Figure 13.6 Horizontal load窶電isplacement curves of the frame tested
constant, and then the horizontal loads are applied and increased until frame failure. The horizontal load versus horizontal displacement relationship results obtained through theoretical analysis and test measurements are both illustrated in Figure 13.6, and the values of the load-carrying capacities are compared in Table 13.1. Good agreement is found in those comparisons which indicates that the second-order elastoplastic analysis can provide satisfactory prediction of the elasto-plastic behaviour and load-carrying capacity of steel frames. Table 13.1 Horizontal load-carrying capacity of the frame tested (kN) Number of specimens Specimen 1 Specimen 2 Specimen 3
Ht (tested)
Hc (analysed)
0.570 0.650 0.490
0.579 0.665 0.485
Hc Ht Ht
100% 1.58 2.31 1.02