Abstract:
Today the demand of high-rise building is rapidly increasing, which are sensitive
to excessive vibrations due to time varying load. Structures subjected to time
varying load such as earthquake and wind load cause large displacement and
severe stress on structural elements. Vibration control is mandatory to counter the
earthquake born vibrations that may be cause of collapse of structure as well as
occupants discomfort. Tuned liquid damper is one of best vibration control
technique hence it does not need external power, economical, easy to maintain and
bi-directional control of vibration. Tuned liquid damper (TLD) can be implemented
as single (conventional TLD) or multiple by its number as well as by its sloshing
frequency.
This research deals on investigation of performance of MTLD for vibration control
of framed structure under seismic load. Total three 3-D framed structures having
seven, twelve and seventeen story was taken as a sample buildings. Modelling and
dynamic analysis of structures without and with MTLD was carried out by
structural analysis programming (SAP2000) software. For consideration of
different seismic load five unscaled recorded earthquake was taken during dynamic
analysis of sample building. Non - linear time history analysis of structure was
conducted as dynamic analysis.
Rectangular shape of tank with water positioned on top of structures was used as
liquid dampers. Many number of damper (until it is possible) which natural
frequencies were distributed around natural frequency of structure were used as
MTLD. Different parametric studies such as effect of number of damper, number of
story, water depth ratio, tuning ratio were conducted to evaluate those effect on
performance of MTLD. The efficiency of MTLD was measured in terms of reduction
of amplitude of top story displacement and acceleration.
The result of these study shows that, with optimum value of number of damper,
water depth ratio (𝛥 = 0.15), tuning ratio (𝛥ᵧ = 0) and constant frequency band
width (𝛥𝑅 = 0.2) MTLD can reduce up to 68.18% of displacement response and
up to 58.95% acceleration response. From this study it can be conclude as, with
proper design parameters MTLD can reduce the earthquake born vibration
significantly even under some uncertainties occur to tune natural frequency of
structure and damper properly.
Performance of Multiple Tuned Liquid Dampers for Vibration Control of Framed
Structures under Seismic Excitation
