Geology Reference
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CONCLUSION
are not yet done. One of the next steps will be the
analysis of real buildings equipped with compen-
sators to learn about the possible improvement if
one uses this method to dimension the protective
equipment. The integration into the design pro-
cess may be achieved by handling problems like
chimneys where passive compensation is used
successfully in many applications.
The application to other structures such as
bridges will be studied. As many structural analysis
codes are designed to deliver the system matrices
to the users, the introduction of parameterised
compensators causes no problems. An analysis
using these matrices and including the compen-
sators produces the fitness values used in the
evolutionary optimization process.
The integration of different excitations and the
scatter of the structures properties have to be done
to provide an estimation of the robustness of the
results. This is not a difficult task but has been
omitted here for the sake of simplicity.
The optimization of the number and position
of compensators takes a very long time if many
positions and numbers have to be checked. We
did it for some selected applications. The integra-
tion of this overlaying optimization is no problem
from the theoretical point of view. From the
computational aspect, it includes a large increase
in the computing power and time used during the
total analysis. Therefore, the procedures have
to be checked for any potential reduction of the
number of individual jobs. There is no doubt that
there are related strategies, for example pseudo
random searches or swarm strategies (Plevris and
Papadrakakis, M. 2011) which often are more ef-
ficient than the opulent ones outlined here. But
the inherent dangers to destroy the power of the
random process by intentional steps should not be
underestimated. So in some cases we found that
swarm optimisation failed to propose efficient
results in the case of out compensation problem,
while on the other hand it was much more efficient
when applied to other problems.
The evolutionary or bionic optimization of passive
tuned mass dampers has been studied discussing
different aspects. The method outlined has the
potential to contribute to more efficient absorbers
at reasonable effort. Some of the main findings
have to be mentioned to show the advantages of
the approach.
The evolutionary optimization of passive
compensators applied to simplified models of
high buildings has the potential to indicate where
and how to use these compensators. The reduc-
tion of the earthquakes' impact may be used as
an estimate as to whether the compensators are
sufficient to prevent severe damage.
Evolutionary optimization helps to find good
proposals for multidimensional problems when
many local maxima have to be considered. At
the prize of large numbers of trials, large sectors
of the high dimensional parameter space may be
searched. If similar proposals are found when us-
ing different initial values and many repetitions,
there is some reason to assume that the proposals
are very good ones if not even the best. In these
cases the method is superior to conventional ap-
proaches as it deals with many maxima and may
find the best one, where other strategies are likely
to converge to suboptimal proposals.
In the case of optimization problems with
many degrees of freedom, the disadvantage of the
large number of studies becomes less important,
as conventional approaches need many calcula-
tions as well and are always likely to find only
the next local maximum.
Passive compensators are popular not only
in earthquake damage control but also for the
stabilization of other structures like bridges and
chimneys. Their advantage is the independence
of active control and the long time availabil-
ity without much inspection and repair. Their
disadvantages are relatively large masses and
deflections which have to be integrated into the
design. So the idea of distributes dampers using
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