Performance Of Multiple Tuned Liquid Dampers For Vibration Control Of Framed Structure Under Seismic Excitation

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