Preliminary Study of Calibration Platform for Energy Dissipation Devices of Bridge Structures

• Main Authors: Kuo-Hsien Fu, 傅國賢
• Other Authors: Jong-Cheng Wu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/19022861891409430158

碩士 === 淡江大學 === 土木工程學系 === 91 === Recently, the trend toward using stronger and lighter material in construction has facilitates the design of modern bridges with longer span. However, the aerodynamics effect involved in the deformation of these bridges is much more significant. Among all, the flutter and buffeting effects are the most detrimental. The buffeting causes excessive deformation of the bridge, whereas the flutter effect can be devastating because it will cause instability under a certain mean wind speed. Therefore, the use of structural control provides a fine approach for suppressing such wind-induced motions. One of the energy dissipation devices is called tuned liquid column damper (TLCD), which is composed of an U shape tube that is filled with liquid. This device uses the mechanism of redistributing the vibration energy from the structure to the moving liquid and further dissipating energy out of it through the head loss damping due to the section orifice. So far, there is no systematic testing platform for the TLCD type of damper in the bridge application. Hence, it is the objective of this thesis to construct an experimental calibration platform to effectively test the characteristic of the TLCD type of damper. In this thesis, the preliminary construction of the calibration platform has been completed, including the testing system, bridge section and TLCD models, and the characteristic calibration of the TLCD device member. The testing system contains a two-axis table driven by two pairs of actuating motors in the heaving and pitching directions, and a two-degree-of-freedom calibration model simulating the bridge deck. In the model-making, a bridge section model (B/D ratio=8) and two TLCD models (section 3*3 and10*10cm2) have been completed. Finally, in testing the characteristic of the TLCD device, the free vibration and forced vibration tests were conducted to measure the frequencies versus different TLCD liquid length and head loss coefficient versus different orifice size. The experimental results obtained were compared with those from the theoretical computation.