Evolutionary Optimization of Passive Compensators to Improve Earthquake Resistance - Design Optimization of Active and Passive Structural Control Systems - page 250

Chapter 11

Evolutionary Optimization
of Passive Compensators to
Improve Earthquake Resistance

Rolf Steinbuch
Reutlingen University, Germany

ABSTRACT

Compensators are widely used to influence the dynamic response of excited structures. The coupling
of additional masses with defined stiffness and damping to the vibrating elements reduces or avoids
unwanted oscillations. In earthquake engineering, compensators often consist of one or a small number
of such additional mass-spring combinations. To come up with a good design of the compensators, a
multidimensional optimization problem has to be solved. As there might be many local optima, evolu-
tionary approaches are the appropriate choice of the optimization strategy. They start with some basic
designs. Then a sequence of generations of design variants is studied. The members of each generation
are derived from the parent generation by crossing and mutation. The best kids are the parents of the
next generation. Optimization results show that the use of compensating systems may essentially reduce
the impact of an earthquake.

INTRODUCTION

of the building may cause severe damage leading
up to the total collapse of the structure. For tall
buildings, the dynamic impact is increased by the
deformability of the height. In many designs, the
classical approach to improve the load-carrying
capacity by increasing the static strength produces
no satisfactory results. Consequently dynamic ap-

Earthquakes are one of the most dangerous and
most fatal natural disasters people face. Shock
waves impose displacements on the bases of build-
ings which are excited to dynamic response (Cho-
pra 2000, pp. 197 - 221). The following vibration