Civil Engineering Reference
In-Depth Information
(g)
(h)
0.03
2500
1250
0.02
0.01
0
-1250
0
-0.01
-2500
0
0.1
0.2
0.3
0.4
0.5
-0.03 -0.02 -0.01
0
0.01
0.02
0.03
Displacement (m)
Plastic rotation (rad)
(i)
(j)
1500
1500
1000
1000
500
500
0
0
-500
-500
-1000
-1000
-1500
-1500
-0.03 -0.02 -0.01
0
0.01
0.02
0.03
-0.03 -0.02 -0.01
0
0.01
0.02
0.03
Plastic rotation (rad)
Plastic rotation (rad)
Figure 8.15
(
Continued
) (g) plastic rotation at PHL #41; (h) moment and plastic rotation relation of PH
#1; (i) moment and plastic rotation relation of PH #37; (j) moment and plastic rotation relation of PH #41.
Assume that all plastic hinges at beams and columns exhibit elastic-plastic behavior with
moment capacity of 1250kN m and 2160kN m, and elastic modules (
EI
) of beam and column
sections are 240000kN m
2
and 480000kN m
2
. The six periods and corresponding modal shape
of vibration are calculated and summarized in Figure 8.14 through the condensed
K
stiffness
matrix in Eq. (8.104) and the mass matrix
M
dd
in Eq. (8.105).
(1) Nonlinear static pushover analysis
We now perform the NSPA procedure on the 6-story structure and the first three models are
considered here. Figure 8.15 shows the relation of the base shear force, moment and plastic
rotation of selected two plastic hinges (PHL #1 and PHL #9) versus roof displacement, and
