Study on the Mitigation of Structure Equipped with Curved Liquid Column Damper Upgraded with TMD System

• Main Authors: Chih-Wen Cheng, 鄭智文
• Other Authors: Hsien-Hua Lee
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/02821856113304043113

博士 === 國立中山大學 === 海洋環境及工程學系研究所 === 102 === TMD and TLCD have been developed for a long time. The tuned mass of TMD is steel ball. It is heavy enough to apply on a heavy structure’s tuned mass to mitigate earthquake vibration. TMD is suitable for use in a tall building with long natural period but need 2 or 3 floors to fit for the length of the pendulum and affect the efficient use of building space. However TLCD can be installed on the roof of building and combine with domestic water and fire water tank with no additional space. The tuned mass of TLCD is water. Its density is so small that the TLCD need a large volume and weight enough for use of vibration mitigation in a heavy structure or a tall building, then affect its intended use. The purpose of this article is based on the development of TMD and TLCD to find another damper that combine the advantages of TMD and TLCD and exclude the disadvantages. First adding a steel rod rolling along the arc on a 2-dimensional movement TLCD is investigated. The steel rod rolling along the arc is similar to TMD and water can provide the damping effect when steel rolls. The 3 equations of motion of steel rolling, liquid movement and single degree of freedom are formatted in this article and Fourier transformation employed to transform displacement of structure between time domain and frequency domain. The curved-TMLCD in this article can mitigate earthquake vibration and reduce the volume of TLCD effectively by studying on the effect of vibration control on different frequency range and comparing with the former research, same as in active control. Next, the result of the steel ball rolling on the 3-dimensional curved surface in water is studied in this article and find that the vibration mitigation effect is similar to TMD that water can provide the damping force when steel ball rolls. This damper is suitable for setting on the structure because of unlimited length of pendulum. By formatting the equations of motion of this rolling damper and calculating the effect of structural displacement, velocity, acceleration and energy absorption, this damper can bring into play the vibration mitigation effect and get rid of the pendulum length restrictions.