Abstract:
Due to modern demands and limited land resources, the construction of high-rise buildings has
increased in recent decades. As a structure's height grows, it becomes more susceptible to
earthquake and wind-induced vibrations. Active, passive, and isolation damping mechanisms
are among the latest methods used to manage structural vibrations. A tuned liquid column ball
damper (TLCBD) is a passive control system that is used to control building movements caused
by wind or earthquakes. TLCBD is an advance form of tuned liquid column damper (TLCD)
with a spherical ball in the middle of the horizontal part of the U-shaped channel filled with
liquid. The spherical ball serves as a moving orifice that improves the vibration mitigation
effect in the TLCBD by providing resistance to water motion. This thesis presents the effects of TLCBD on steel diaphragm structure, taken as a multi degree
of freedom (MDOF) system against unidirectional seismic loading. TLCBD was tuned with
the fundamental natural frequency of the structure and placed on multiple stories of the primary
structure for getting most optimized scenarios. For optimization three types of liquids were
used including water, sugar solution and motor oil with steel ball. Via a series of shake table
experiments, the efficacy of the TLCBD was investigated against arbitrary seismic loading
which was very close to El Centro (1940). For performance assessment, the TLCBD
acceleration response was measured for each case under all loading conditions and compared
to a structure without TLCBD. The efficiency of the TLCBD is based on the type of liquid used
in it along with its location on the structure.
