Design of coupled tuned liquid column gas dampers for multi-mode reduction in vibrating structures

Abstract

Tuned liquid column gas dampers (TLCGD) show excellent energy and vibration absorbing capabilities appropriate for earthquake engineering. The objective of this work is to introduce a new concept of coupled tuned liquid column gas dampers which allow an extended field of applications. In the proposed configuration, several absorbers are connected in a spatial chain generating a multi-degree of freedom damper system which can be tuned to a selected number of structural modes. Because all absorbers vibrate at different natural frequencies simultaneously, the proposed design represents an improvement over conventional TLCGD which can only be tuned to a single structural mode. Another benefit of multi-mode tuning is the significant increase in active liquid mass compared to other damping devices. For a most effective vibration reduction, a numerical tuning process in state space will deliver the free system natural frequency and damping ratio of all absorbers. The capabilities of the new damping device are demonstrated on a simple laboratory structure that is investigated numerically and experimentally. The results illustrate the excellent energy dissipating properties of the proposed setup and emphasize the adequacy of coupled TLGCD for base-isolated structures. A notable benefit of such types of dampers lies in their lack of moving mechanical parts, their cheap and easy implementation into civil engineering structures and low maintenance costs. Possible modifications with respect to natural frequency and even of the damping properties can be performed with little additional expenses, and the additional weight due to the liquid mass may be used as a possible reservoir, e.g., for fire fighting. Apart from that, they exhibit a performance that is comparable to tuned mass dampers.

Mathematical modeling and optimization scheme for omnidirectional tuned liquid column dampers

“…As a more matured tuned damper, which eliminates the need for problematic installations of TMDs and rectified the substantial inactive liquid of TLDs, the tuned liquid column damper (TLCD) [8,9] is invented. A number of notable studies on TLCD may include the mathematical description of TLCDs and their optimum parameters using sinusoidal and/or random vibrations, such as [10][11][12][13][14][15][16][17][18][19], passive TLCDs, such as [20][21][22][23][24][25][26][27][28][29][30][31], and semi-active and active TLCDs, such as [32][33][34][35][36][37][38][39][40][41].…”

Dynamic coupling on the design of space structures

“…Shape memory alloys (SMA) can be employed as TMD for seismic mitigation [25]. Other designs with the same approach are the tuned liquid mass damper (LTMD) [26], the tuned liquid column gas damper [27], the magnetically tuned mass damper [28], the magnetorhelogical damper with semi-active TMD [29,30] and the piezoelectric vibration energy harvesting beam as a TMD [31].…”

Study on the Dynamic Performance of a Modified Tuned Liquid Column Damper

“…A compound STLCD to extend the range of the STLCD applications was proposed. [18]. Shum et al [19] performed a theoretical analysis of the multiple STLCD to decrease the vibration of cable-stayed bridges under wind action.…”

“…Where n is the polytropic index (n=1: 1.4 for air) [13][14][15][16][17][18][19][20][21], A is the cross-sectional area of the STCLD and h is the air column height. Therefore, the stiffness of the air spring in each vertical column may be obtained as:…”