Presenting an Optimal Design Procedure for a Variety of TLCDs to Improve the Seismic Response of Offshore Platforms

Abstract

Passive Tuned Liquid Column Dampers, which are cost-effective, easy to implement, and reliable structural vibration control devices, have received significant attention from designers and researchers. Tuned liquid column dampers are divided into four categories based upon their configuration, i.e. the U-shaped TLCD (UTLCD), V-shaped TLCD (VTLCD), TLCD with no Uniform Section (LCVA) and gas TLCD or with spring (TLCGD) to organize this review systematically. In this study, first, the seismic performance of a jacket-type platform equipped with UTLCD under three earthquake records is studied numerically with MATLAB software. Then, according to the value of the platform natural frequency, the design of a variety of TLCDs has been explored. To optimize the dynamic behavior of the damper-platform system, a general flow chart for the design of TLCDs was presented. Furthermore, discussions and investigations have been conducted on the effects of a fluid sloshing phenomenon on damper design. It has become apparent that using LCVA or TLCGD is the best solution to provide a reliable and effective damper design if the natural frequencies of the platform are below 0.5 Hz. TLCGD has a very small limit in terms of optimum design between these two dampers.

Keywords

• seismic control
• tuned liquid column damper
• efficiency coefficient
• optimum design