Structural vibration control using modified tuned liquid dampers

A tuned liquid damper (TLD) is a passive damper consisting of a solid tank filled with water that uses the water sloshing inside it to dissipate energy. The standard TLD configuration is where a TLD is connected rigidly to the top of the building. It has been popular as a control device for wind excitation. Earlier research has shown that the TLD behaviour is amplitude dependent, i.e. it is more effective when excitation amplitude is increased and more energy is dissipated due to sloshing. A modified TLD configuration is proposed here, where the TLD rests on an elevated platform that is connected to the top of the building through a rigid rod with a flexible rotational spring at its bottom. For particular values of the rotational spring flexibility, the rotational acceleration of the rod is in phase with the structure top acceleration and the TLD base is subjected to a large amplitude acceleration that increases its effectiveness. It should be noted that when the rotational spring is rigid, the modified and standard TLD configurations are identical. It is seen that, for aiven structure with modified TLD configuration, there exists an optimum value of the rotational spring stiffness for which the effectiveness of the modified TLD is maximum. Thus, it is seen that an optimally designed modified TLD configuration may be more effective as a structural control device than a standard TLD configuration, for both harmonic and broad-band earthquake motions.

[1]  Limin Sun,et al.  Tuned liquid damper (TLD) for suppressing horizontal motion of structures , 1992 .

[2]  N. Popplewell,et al.  Nutation Damper Undergoing a Coupled Motion , 2004 .

[3]  F. Welt,et al.  On the suppression of vibrations using nutation dampers , 1990 .

[4]  A. Akinturk,et al.  An Efficient Liquid Sloshing Damper for Control of Wind Induced Instabilities , 2001 .

[5]  Yukio Tamura,et al.  Practical application of nutation damper for suppressing wind-induced vibrations of airport towers , 1992 .

[6]  Yozo Fujino,et al.  Interaction of tuned liquid damper (TLD) and structure. Theory, experimental verification and application , 1989 .

[7]  Yozo Fujino,et al.  A model of tuned liquid damper for suppressing pitching motions of structures , 1995 .

[8]  Yukio Tamura,et al.  Effectiveness of tuned liquid dampers under wind excitation , 1995 .

[9]  Pradipta Banerji,et al.  EFFICIENT NUMERICAL SCHEMES TO ANALYSE EARTHQUAKE RESPONSE OF STRUCTURES WITH TUNED LIQUID DAMPERS , 2006 .

[10]  J. J. Stoker.  Water Waves: The Mathematical Theory with Applications , 1957 .

[11]  N. Isyumov,et al.  Numerical flow models to simulate tuned liquid dampers (TLD) with slat screens , 2005 .

[12]  A. Kiureghian.  A COHERENCY MODEL FOR SPATIALLY VARYING GROUND MOTIONS , 1996 .

[13]  Harry Yeh,et al.  Behavior of sloped-bottom tuned liquid dampers , 2001 .

[14]  Pradipta Banerji,et al.  Tuned liquid dampers for controlling earthquake response of structures , 2000 .

[15]  A. Mcguire,et al.  What is it to be a model? , 2000, HEPAC Health Economics in Prevention and Care.

[16]  Chan Ghee Koh,et al.  Theoretical and experimental studies on rectangular liquid dampers under arbitrary excitations , 1994 .

[17]  Vinod J. Modi,et al.  AN EFFICIENT LIQUID SLOSHING DAMPER FOR VIBRATION CONTROL , 1998 .

[18]  Yozo Fujino,et al.  Modelling of tuned liquid damper (TLD) , 1992 .