Investigation of the Effect of Tuned Liquid Dampers (TLDs) on Multi-Degrees of Freedom (MDOF) Structures

• Main Authors: Quoc Bao Nguyen, 阮國寶
• Other Authors: Kuo-Chun Chang
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/03201817027997527085

碩士 === 國立臺灣大學 === 土木工程學研究所 === 103 === Current trends in the construction industry demand taller and lighter structures, which are also more flexible and have quite a low damping value. Vibrations of such structures due to wind, earthquake, and other dynamic disturbances can create problems from serviceability or safety viewpoints. Several techniques are available today to minimize the vibration of the structure, in which concept of using Tuned Liquid Damper is a newer one. Tuned Liquid Damper (TLD) is a new type of mechanical damper which relies on the sloshing of shallow liquid in a rigid tank for suppressing structural vibrations. Recent growing interest in liquid dampers is attributable to several potential advantages, such as: low costs; easy to install in existing structures; applicable to temporary use; non-restriction to unidirectional excitation; effective even for small-amplitude vibrations; and few maintenance requirements. The effect of rectangular TLDs on responses of a multi-degree of freedom (MDOF) structure to lateral dynamic excitations was studied theoretically and experimentally in this research. Numerical analysis was implemented by using the nonlinear model of rectangular TLD which was proposed by Sun L.M. [1]. In this study, by applying Sun’s model, which is based on the shallow water wave theory, to a MDOF shear building, the structural responses under Harmonic Ground Motion, El Centro Earthquake and TCU072 Earthquake were predicted, respectively. The shaking table test was then carried out with a three-story steel shear building specimen to verify the theoretical results. Both the numerical analysis and experiment considered the cases of different numbers of TLDs attached to the main structure. This research also investigated the influence of variation in TLD parameters including Tuning ratio, Depth ratio and Mass ratio on structural responses as well as estimated the damping ratio of the structure with and without TLDs.