Optimal Placement of Controller for Seismic Structures - Design Optimization of Active and Passive Structural Control Systems - page 23

Figure 17. Objective function J1 vs. different algorithms and ground motions

• Exhaustive Single Point Substitution

(ESPS)

4. The maximum of peak interstory drifts of
buildings subjected to a given earthquake
(J4)

Two types of damper placement strategies can
be adopted: Four different earthquake records have been

considered to investigate the dependence of the
optimal locations on the stochastic nature of the
earthquake excitation.

• Distinctive Location, with only one damp-

er in any story unit

• Repeated Location, with more than one

damper in any story unit • Two are near field earthquakes: Kobe

(1995) and Northridge (1994)

Numerical results presented in this chapter
are obtained using the Repeated Location damper
placement. The optimal locations of dampers have
been investigated by optimizing the following
types of objective functions:

• Two are far-field earthquakes: El Centro

(1940) and Hachinohe (1968)

The applications of the proposed methods for
the optimal locations of dampers are investigated
for three types of buildings:

1. The average dissipated energy by dampers
(J1)
2. The weighted sum of damping ratios of
selected modes of the building (J2)
3. The maximum story absolute acceleration
(J3)

1. A 6 story building with soft story behavior
2. A 10 story building with identically con-
structed story units
3. A 30 story building with stiffness variation
along the story height