Sensitivity of The Performances of Seismic Isolation Platforms to Small Deviations in Mechanical Properties of Seismic Isolators
When subjected to high accelerations, vibration-sensitive devices could go out of service temporarily or could be damaged permenantly. Since most of these equipment are housed in data collection centers, industrial structures, hospitals, or universities, they have cruial roles in terms of public health, public security, and national economy. Therefore, it could lead to big problems if these devices were damaged or went out of service even for a short period of time. Seismic isolation platforms are base isolation systems placed underneath the structural systems which contain sensitive equipment in order to protect these devices from the harmful earthquake vibrations. Earthquake accerations coming to a seismic isolation platform are transmitted to the sensitive equipment in a reduced fashion. However, since the tolerable acceleration levels are too low, it is very important to accurately determine the seismic performance of such a platform. On the other hand, there could be small deviations in the mechanical properties of the seismic isolators forming the isolation systems from the design values due to errors in the manufacturing process of these isolators. Similarly, there could be small deviations in the mechanical properties of the superstructures placed on the platform. In this study, the influence of possible small deviations in the mechanical properties of seismic isolators or the structural system sitting on the seismic isolation platform is investigated via numerical experiments using historical earthquake records. Isolator displacements, total accelerations transmitted to the floors of the structural system housing the sensitive devices, and base shears are considered as the seismic performance criteria. Sensitivity analyses are conducted for both linear and nonlinear isolation systems. Various isolation periods and isolation damping ratios are considered. Results show that different structural parameters affect different performance criteria at different levels and sensitivity depends on the characteristics of the isolation system.
TÖREN Alican
Danışman : Yard.Doç.Dr.Turgay ÇOŞGUN
Anabilim Dalı : İnşaat Mühendisliği
Mezuniyet Yılı : 2011
Tez Savunma Jürisi : Yard.Doç.Dr.Turgay ÇOŞGUN
Prof.Dr.Mustafa KARAŞAHİN
Prof.Dr.Namık Kemal ÖZTORUN
Doç.Dr. Güray ARSLAN
Yard.Doç.Dr. Ömer Faruk KÜLTÜR
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