Tuned Sloshing Damper in Response Control of Tall Building Structure

Transcription

1 Publhed Onlne on 9 June 016 Proc Indan Natn Sc Acad 8 No. June Spl Iue 016 pp Prnted n Inda. DOI: /ptna/016/48415 Reearch Paper Tuned Slohng Damper n Repone Control of Tall Buldng Structure S K BHATTACHARYYA Profeor, Department of Cvl Engneerng, IIT Kharagpur, Inda (Receved on 16 Aprl 016; Accepted on 0 May 016) The paucty of pace and requrement of buldng nfratructure ha drven u to explore for taller buldng ytem. Alo a large number of contructon materal ha emerged and are beng ued extenvely n buldng. The uage of lght weght hgh trength materal reduce the pace requrement and alo become economcal. However, uch tructure have tructurally become uceptble to the lateral loadng generated due to wnd or earthquake. Attempt are made to control the repone of tall buldng ytem by ntroducng control mechanm n the form of actve, pave or hybrd ytem. Uage of lqud torage tank n tall buldng ytem n the form of a pave control devce prove effectve. Several work have been carred out n the pat to undertand the effcacy of uch ytem, whch popularly known a tuned lqud damper or tuned lohng damper (TSD). The preent paper deal wth the development of a numercal code to demontrate the effcacy of uch tuned lohng damper conderng flud tructure nteracton effect. Keyword: Slohng; Damper; Repone Control; Buldng, Pave Sytem; Tuned Slohng Damper (TSD) Introducton The paucty of pace and the preent trend toward tall buldng, the ue of lghtweght, hgh trength materal often accompaned by ncreaed flexblty and a lack of uffcent nherent dampng, ncreae ther uceptblty to exctaton uch a due to wnd, ocean wave or earthquake. To reduce the rk of tructural falure partcularly durng a catatrophc event t ha become mportant to earch for practcal and effectve devce for uppreon of the vbraton generated due to uch exctaton. Th ha necetated explorng mechanm to uppre the vbraton of uch tall buldng by ome utable devce. The devce ued for mtgatng tructural vbraton may be categorzed accordng to ther energy conumpton a Pave, Actve and Sem-actve or Hybrd control ytem. Several attemptn the pat have been made to evolve utable type of tructural control devce and derve ther effcace. Thee nclude work of Houner et al., 1997; Spencer Jr. and San, 1997; Soong and Spencer Jr., 00 and Spencer Jr. and Nagarajaah, 003, amongt other.pave control devce are ytem whch do not requre external energy upply. Such ytem are relable nce they are unaffected by power outage, whch are common durng natural calamte. Example of uch ytem nclude bae olaton (ung elatomerc and lead rubber bearng), energy dpaton devce uch a metallc damper, vcou damper, frcton damper, tuned ma damper, tuned lqud damper etc. (Soong and Darguh, 1997; Kaa et al., 1998). Actve control ytem on the other hand nvolve conderable amount of external power to operate actuator that upply a control force to the tructure. The control force generated dependng on the feedback of the tructural repone. Thee are more effectve than pave devce becaue of ther ablty to adapt to dfferent loadng condton and to control dfferent mode of vbraton. Example of uch ytem nclude actve ma damper (AMD), actve bracng ytem, etc. (Houner et al., 1994; Sakamoto et al., 1994). Sem-actve ytem are vewed a controllable devce, wth energy requrement le than typcal actve control ytem nce external power only ued to change devce properte uch a dampng *Author for Correpondence: E-mal: rmankb@gmal.com

2 4 S K Bhattacharyya or tffne, and not to generate a control force. Thee functon a pave devce n cae of power falure. Example of uch ytem nclude varable orfce damper, electro-rheologcal damper, magnetorheologcal flud damper, em-actve varable tffne tuned ma damper (SAIVS-TMD) etc. (Syman and Contantnou, 1999). Hybrd control ytem utlze the ueful charactertc of both ytem whch mple the combned ue of pave and actve ytem or pave and em-actve ytem. The mot common combnaton are hybrd ma damper (HMD), whch combne tuned ma damper wth actve actuator. Dampng defned a the ablty of the tructure to dpate a porton of the energy releaed durng a dynamc loadng event and thu one of the mot mportant parameter that lmt the repone of the tructure. Attachment of lqud tank to the tructure ntroduce capablty of nducng dampng n the ytem. The lohng moton of the lqud that reult from the vbraton of the tructure dpate a porton of the energy releae by the dynamc loadng and therefore ncreae the equvalent dampng of the tructure. Thee tank devce are referred to a Tuned Slohng Damper (TSD). In general lohng of lqud caue problem n tank devce, however, n th cae the lohng of lqud n tank ued to t advantage. The TSD ytem rele on the lohng wave developng at the free urface of the lqud to dpate a porton of the dynamc energy. The growng nteret n lqud damper due to ther low captal and mantenance cot and ther eae of ntallaton nto extng and new tructure. Thu TSD concept repreent an excellent technque for up-gradng the emc retance of both extng and new tructure.the performance of TSD rele manly on the lohng of lqud at reonance to aborb and dpate vbraton energy of the tructure. The full cale meaurement of wnd nduced vbraton of two actual tall tructure - Nagaak Arport Tower (heght 4 m) and Yokohama Marne Tower (heght 101m) were carred out (Fujet al., 1990). The dplacement were reduced to about 40% upon ntallaton of Tuned Slohng Damper. Dynamc force frequency repone functon of TSD wa alo expermentally determned to tudy the effect of the TSD n whch the natural frequency of the water nde the contaner wa tuned to that of the tructure. The mtgaton of wnd nduced moton of buldng utlzng tuned lohng damper wa tuded (Ahan Kareem, 1990). It wa demontrated by the author that a lohng damper can effectvely reduce the moton of buldng when the fundamental lohng and buldng frequence are ynchronzed. A em analytcal model for TSD ung a rgd rectangular tank flled baed on hallow water wave theory wa propoed (Sun and Fujno, 199). The repone of a SDOF tructure ftted wth a TSD wa expermentally tuded and t wa found that TSD work atfactorly for uppreng tructural vbraton nvetgated The ue of lqud damper whch are tuned to dfferent vbraton frequence of a mult-degree-of-freedom tructure wa tuded (Koh et al., 1994). It wa oberved by the author that the poton of the lqud damper ha a gnfcant effect on the vbraton repone. Takah Nomura, 1994 employed Arbtrary Lagrangan-Euleran (ALE) formulaton to deal wth the free urface moton of the lqud n TSD. Nonlnear nteracton of lqud moton and tructure moton wa captured by the propoed computatonal method for the vortex-excted ocllaton of a crcular cylnder a well a a TSD-tructure nteracton problem. The full-cale meaurement of the wnd-nduced repone of buldng to prove the effcency of tuned lqud damper (TLD) wa carred out (Tamura et al., 1995). The wnd-nduced repone of the buldng were meaured before and after the ntallaton of TLD. Vbraton perceved by occupant due to daly wnd wa gnfcantly reduced. The TLD could reduce the acceleraton repone durng trong wnd down to 1/-1/3 of the repone wthout the TLD, thu the habtablty and ervceablty of buldng were conderably mproved. Ikeda and Nakagawa, 1997 tuded the nonlnear lohng damper n a rectangular tank both analytcally and expermentally. The water tank attached to a tructure to uppre the horzontal vbraton of the tructure caued by a nuodal exctaton. Quanttatvely good agreement wa obtaned between the theoretcal charactertc and the expermental reult. Warntcha and Pnkaew, 1997 propoed a new mathematcal model of lqud lohng n rectangular tank, whch nclude the effect of flow-dampenng devce. Th model can accurately repreent the complex behavour of lqud lohng and, at the ame tme, mple enough to be ued n engneerng calculaton, and more mportantly, the effect of flow-dampenng devce can be analytcally evaluated. Reed et al., 1999 numercally

3 Tuned Slohng Damper n Repone Control of Tall Buldng Structure 5 modelled the TLD a an equvalent tuned ma damper wth non-lnear tffne and dampng. Thee are determned uch that the energy dpaton provded by the Non-lnear Stffne and Dampng (NSD) equvalent to that of the TLD. Th NSD model capture the behavour of the TLD ytem under a varety of loadng condton. Thu NSD model preented here an equvalent TMD repreentaton of the TLD. An algorthm for updatng the NSD dampng and the tffne coeffcent n a tme htory analy of a SDOF tructural ytem ha been provded. Kanok-Nukulchaand Tam, 1999 propoed a Lagrangan dplacement-baed flud element to model large ampltude free urface moton of nearly ncompreble vcou flud n a tank of rectangular cro-ecton under dynamc exctaton for tuned lqud damper applcaton. The penalty method employed to enforce the nearly ncompreble charactertc of flud. The effectvene of the propoed model wa verfed by expermental reult from the lterature. The reult how that the propoed nonlnear flud element can predct non-lnear behavor of large ampltude lohng due to dynamc exctaton, epecally at near-reonant regon.yamamoto and Kawahara, 1999 preented a numercal tudy for tructural control ung a tuned TLD, whch cont of old tank flled wth lqud. The author demontrated that the computed reult are cloer to the expermental one. Banerj et al. (000) carred out the tudy of the dynamc behavor of SDOF tructure, rgdly upportng a rectangular TLD tank wth hallow water. An attempt wa made to defne approprate degn parameter of the TLD that effectve n controllng the earthquake repone of a tructure through parametrc tude. B. Nanda, 010 had carred out a work on the applcaton of tuned lqud damper for controllng tructural vbraton of buldng. The author made an exhautve tudy and had demontrated the effcacy of the tuned lohng damper. J Mondal, 014 had carred out an experment n the laboratory to demontrate that the lqud lohng help n reducng tructural vbraton of framed tructure. N K Ra et al., 013 had attempted to reduce the repone of extng buldng by carryng out retrofttng ung tuned lqud damper. The author had demontrated that lqud lohng n tank can help reducng the vbratonal repone of tructure even when retroftted n extng buldng. Tat et al. (005) formulated both lnear and non-lnear numercal model of a TLD wth lat creen. The nonlnear model of a TLD equpped wth dampng creen (Kaneko and Ihkawa, 1999) preented. The non-lnear lohng repone potulated ung hallow water theory (Lepelleter and Rachlen, 1988). A procedure to calculate the theoretcal value of the force coeffcent of a lat-type creen preented and verfed from expermental reult and applcable for both wnd (mall exctaton) and earthquake (large exctaton) loadng.the non-lnear model capable of modellng a TLD equpped wth multple creen at varou creen locaton nde the tank. The non-lnear model alo verfed over a range of practcal flud depth to tank length rato value. An expermental program conducted to ae the applcablty of the theoretcally determned lo coeffcent by a TLD durng dynamc exctaton. Franden, 005 developed a fully non-lnear -D -tranformed fnte dfference olver baed on nvcd flow equaton n rectangular tank. The flud moton decrbed by non-lnear potental flow equaton allowng teep non overturnng wave to be captured. Two-dmenonal oluton are obtaned ung a fnte-dfference tme-teppng cheme on adaptvely mapped grd. The olver alo remove the need for free-urface moothng. The flud model coupled to an elatc upport tructure. The effectvene of the TLD dcued through predcton of couplng frequence and repone of the tank-tructural ytem for dfferent tank ze, ma rato between flud and tructure and tunng rato. Bhattacharyya et al., 006 had formulated a mxed Euleran-Lagrangan fnte element model to compute the non-lnear lohng ampltude of lqud n lqud flled rectangular and crcular cylndrcal contaner ubjected to nuodal bae exctaton. The oluton obtaned by the Galerkn method. The fourth-order Runge-Kutta method employed to advance the oluton n the tme doman. A re-grddng technque appled to the free urface of the lqud, whch elmnate the numercal ntablte wthout the ue of artfcal moothenng. Th fnte element method ued for computng the non-lnear lohng repone of lqud n a two dmenonal rgd rectangular tank wth baffle and crcular cylndrcal contaner wth annular baffle. Valdty of the preent model checked by comparng avalable reult for the tank wthout baffle. The effect of baffle parameter uch a poton, dmenon, and number on the non-lnear lohng repone are alo examned.

4 6 S K Bhattacharyya Tuned Slohng Damper can be broadly clafed nto two categore, hallow-water and deepwater damper baed on the rato of the water depth to the tank length n the drecton of moton. The TSD ytem rele on the lohng wave developng at the free urface of the flud to dpate a porton of the dynamc energy. The growng nteret n lqud damper due to ther low captal and mantenance cot and ther eae of ntallaton nto extng and new tructure. Thu TSD concept repreent an excellent technque for up-gradng the emc retance of both extng and new tructure. The lqud tank attached to the tructure, undergoe lohng moton that reult from the vbraton of the tructure, dpate a porton of the energy releaed by the dynamc loadng and therefore ncreae the equvalent dampng of the tructure. In the preent paper, dynamc charactertc of an dealed buldng tructure n -D form are tuded when attached wth tuned lqud flled tank a pave damper under dynamc exctaton. The two ytem, lqud ytem and the tructural ytem n Fg. 1 are tuded n uncoupled form. The couplng between the two ytem acheved through teraton. condered. The tatonary lqud heght h and repreent the free urface lohng elevaton. Flud doman bounded by the free urface S 1 and fludold boundary nterface S. Sold boundary cont of tank wall and tank bottom a hown n Fg.. Fg. : Lqud lohng n rgd tank Governng Equaton Conderng the lqud a nvcd and ncompreble, and flow rrotatonal, governng equaton may be wrtten by Laplace equaton n a: 0 (1) where, (x, y, t) the velocty potental. However, n a movng tank the total velocty potental may be plt nto two part, potental functon t due to tank moton and dturbed potental functon due to flud moton. () t For the tank movng n horzontal drecton n vertcal plane, t may be expreed a t x x t (3) Expreng Laplace equaton n term of 0 (4) Fg. 1: Structure and flud ytem Theoretcal Formulaton Boundary Condton In a rgd contaner, oluton of Laplace equaton mut atfy the boundary condton A rgd contaner of wdth L contanng ncompreble and nvcd lqud ubjected to horzontal ocllaton n 0 on S (5)

5 Tuned Slohng Damper n Repone Control of Tall Buldng Structure 7 where n the unt normal vector drawn outwardly to the old boundary x 0 ; 0 on S y x L / yh (6) In Euleran form Knematc and Dynamc Boundary condton on free lqud urface are on S 1 y t x x (7) Knematc B.C Fg. 3: Fnte element model of lqud lohng 1 g x xt 0 on S t Dynamc B.C 1 (8) A dcued earler to tart wth, ntal condton may be taken a a In Lagrangan form, equaton may be wrtten dx dy ; Knematc B.C dt x dt y (9) d 1 g x xt dt y t Dynamc B.C Fnte Element Formulaton Intal Impule Condton (10) Intally the flow tart wth a mall horzontal tank velocty. Callng th a an ntal mpule condton, baed on lnear theory 0 ; 0 on free urface & x x t t t x x t on free urface 0 ; 0 where x t (0) ntal mall tank velocty. (11) (1) For fnte element analy entre flud doman dcretzed ung four noded quadrlateral element. x x t on free urface 0 ; 0 (13) Wth the known velocty potental at free urface node Laplace equaton olved to obtan unknown nodal velocty and preure atfyng the boundary condton. Fnte Element Soluton of Laplace Equaton Spatal dcretzaton of Laplace equaton done by mean of Galerkn weghted redual technque. approxmated a N n Applyng Galerkn prncple N x y dx dy 0 (14) (15) Aumng n the total number of nodal pont of the dcretzed lqud doman and n d be the number of node correpondng to the free urface boundary, the unknown nodal value gven by n n d, alo equal to the number of equaton reultng from Galerkn approxmaton. Applyng approprate boundary condton and known velocty potental d at free urface node,

6 8 S K Bhattacharyya the reultng equaton become N d N N dx dy K j j n jn \ nd N N (\) dx dy n n j d j d jn d K f where nodal nalue N the vector of unknown N N N j j j x jn \\ n d x y jn n d y N N N N (16) (17) dx dy (18) j j dj dx dy x jn x y d jn y (19) d F-S Interacton Model The two ytem, flud ytem and the tructural ytem are tuded n decoupled form. The two ytem are terated n the ene that flud ytem wll experence the floor repone and n turn flud ytem wll exert hydrodynamc lohng force on the tructure. The equaton of moton of the tructure beng olved for a flud-tructure nteracton problem : [ M ] { u } [ C] { u } [ K]{ u } F F (0) t t t e d Where, M ma matrx of the tructure, C dampng matrx of the tructure, K the tffne matrx, u t nodal dplacement vector. F e the exctaton force vector, for earthquake exctaton; F e = [M]{l} x g l the nfluence vector of the tructure ubjected to ground exctaton. F d the total hydrodynamc lohng force due to lohng n tank, N d F { m } F d 1 F the hydrodynamc lohng force due to lohng of TSD at th floor, N d the number of lqud damper ntalled over the torey, m the nfluence vector for the lqud damper tuated at th floor. x g ground acceleraton. Stffne matrx K and content ma matrx M for the gven mult-degree freedom tructure determned. Dampng matrx C of the tructure derved from Raylegh dampng whch conder ma and tffne-proportonal dampng for the cae of clacal dampng. Natural frequence and the natural mode hape of vbraton are obtaned by performng the free vbraton analy of the tructural ytem. Incorporatng the dampng term n Dynamc boundary condton d dt 1 y t g x xt. (1) the dampng coeffcent n the dampng term., whch prmarly take nto account the dampng effect due to lohng of the lqud. x t the bae acceleraton nduced n the tank due to tructure repone whch ame a the floor acceleraton, to whch the TSD rgdly connected to. Thu x t can be obtaned a Calculaton of Slohng Force T { }.{ t} m u. Hydrodynamc lohng force obtaned by ntegratng the hydrodynamc preure over the tank projected area, whch n turn act on the tructure a bae hear force. F 1 p( L /, y,) t dy h b p( L /, y,) t dy h () Where 1 and are the free urface lohng elevaton at the two de wall of the tank, and p(l/

7 Tuned Slohng Damper n Repone Control of Tall Buldng Structure 9,y,t) and p( L/,y, t) are the lqud preure at x = ±L/. b breadth of tank, the dmenon n other orthogonal drecton. The convergence n the oluton acheved by an teratve procedure both for tructural dplacement and the preure developed n the lqud. Parametrc tude are carred out to oberve the effect of loh dampng n the repone of the tructural ytem. The parameter tuded are the tunng rato, rato of lohng frequency to modal frequency of tructure, ma rato, rato of ma of damper to tructure, water depth rato, rato of tatonery lqud heght to length of the tank etc. A fve toreyed buldng wth overhead water tank a TSD condered for the parametrc nvetgaton. Properte of the beam and column are unform throughout the torey. Frt modal frequency for the condered tructure 6. rad/ec. TSD wll be ued to uppre the frt vbraton mode of th buldng ubjected to ground exctaton. Tunng the fundamental lohng of the overhead water tank (a TSD) to the frt modal frequency of the buldng gve the length of the tank a 0.8 m n the drecton of the exctaton. Fg. 4 how the detal of the buldng condered for parametrc tude. For the parametrc nvetgaton to determne the optmal TSD parameter the buldng ubjected to harmonc ground exctaton. u x t g 0. e. n( e.); where x m; and 6. rad / ec 0 Thu the three frequence namely tructure modal frequency, lohng frequency and the exctaton frequency are kept ynchronzed Fg. 5(A) how the dplacement of the top floor of the buldng for a ma rato of 1.5. Fg. 5(B) how the dplacement of the tructure and the lohng dplacement. The phae dfference of the two dplacement qute dtnct. In the preent model, water depth rato (h/l) kept n the range of 1-. Parametrc nvetgaton A e B Fg. 4: Tet Structure for the parametrc nvetgaton Fg. 5: Repone of tructural ytem wth and wthout Tuned Slohng damper. Column heght = 4m, beam length = 8 m, dampng rato = 5%, EI beam = 17.5e-4 knm, EI column = 7.9e-4 knm, Beam croectonal area = 0.1m, Column croectonal area = 0.4m, UDL on beam = 40 kn/m

8 30 S K Bhattacharyya Table 1: Performance of TSD agant varyng water depth Water depth rato (h/l) Meh ze 1x1 1x1 14x1 16x1 18x1 0x1 Top floor dplacement (m) Percentage reducton Table : Performance of TSD agant varyng ma rato Ma Proporton % 5 th =100% 5 th =90% 5 th =80% 5 th =70% 5 th =60% 4 th =0 % 4 th =10 % 4 th =0 % 4 th =30 % 4 th =40 % Top Floor Dplacement (m) Percentage Reducton Other parameter aumed n the tudy are: Structure Dampng = 5%; Ma Rato = %; Tunng Rato = 1; Water Depth Rato = 1; Top Floor Dplacement wthout TSD = 0.09 m have been carred out to analye the performance of TSD wth the varyng water depth rato. For the varyng water depth rato nherent dampng n the tructure kept 5% and the ma rato a % keepng the water tank at the top floor (.e. 5 th floor). Table 1 ndcate the percentage reducton n the dplacement of the top floor for dfferent water-depth rato, wth the followng parameter: Structure Dampng = 5%; Tunng Rato = 1; Ma Rato = %; Top Floor Dplacement wthout TLD = 0.09 m. A parametrc tudy wa undertaken to tudy the effect of ma proportonng on the dplacement of the buldng tructure. Accordngly the ma wa dtrbuted between two floor ntead of lumpng at one floor. Table ndcate the percentage reducton n floor dplacement due to the ma dtrbuton n two floor. Concludng Remark Maxmum percentage reducton n the repone of the tructure a top floor dplacement wa obtaned for water depth rato equal to 1. Increang the water depth rato from 1 to caued the gradual declne n the effectvene of the overhead water tank a damper, but tll water depth of provded a gnfcant amount of percentage reducton n the top floor dplacement a 4.1%. Th mpled that the water depth rato n the range of approxmately may provde apprecable amount of mtgaton up to 44%. Invetgaton carred out for the varyng ma proporton howed that TSD mantaned t performance qute effectvely even after proportonng the damper ma a 100-0, 90-10, 80-0, 70-30, and % over the top two torey. In the preent cae of fve torey tructure under harmonc ground exctaton maxmum percentage reducton of 47.7% n the repone of the tructure a top floor dplacement wa oberved for ma proportonng of 90% at 5 th floor and 10% at 4 th floor. It wa alo oberved that tuned water tank perform effectvely a a damper even for the ma proportonng of 60% at 5 th floor and 40% at 4 th floor provdng a percentage reducton of 44.4 n the tructure top floor dplacement. Sgnfcant performance of deep-water TSD wth varyng ma proporton mpled that f enough top floor pace not avalable for the ntallaton of TSD one can carry out the proportonng of the damper ma n the upper torey for mult-toreyed buldng. Alo from the tructure degn pont of vew ntead of lumpng the ma at the top torey proportonng of damper ma n the upper torey wll reduce the ncreae n the tree n the tructural member due to the addton of the damper ma.

9 Tuned Slohng Damper n Repone Control of Tall Buldng Structure 31 Reference Bwal K C, Bhattacharyya S K and Snha P K (006) Non-lnear lohng n partally lqud flled contaner wth baffle Internatonal Journal of Numercal Method n Engneerng Chen W, Haroun M A and Lu F (1996) Large ampltude lqud lohng n emcally excted tank Earthquake Engneerng and Structural Dynamc Faltnen O M, Rognebakke O F and Tmokha A N (005) Clafcaton of three-dmenonal nonlnear lohng n a quare-bae tank wth fnte depth Journal of Flud and Structure Franden J B (005) Numercal predcton of tuned lqud tank tructural ytem Journal of Flud and Structure Ikeda T and Nakagawa N (1997) Non-lnear vbraton of a tructure caued by water lohng n a rectangular tank Journal of Sound and Vbraton J Mondal et al., (014) Tuned lqud damper Proceedng of 3 rd Internatonal Conference on Mechancal Engneerng and Mechatronc, Augut 14-15, paper 68 Kanok-Nukulcha W and Tam B T (1999) Structure-flud nteracton model of tuned lqud damper Internatonal Journal for Numercal Method n Engneerng Koh C G, Mahatma S and Wang C M (1995) - Reducton of tructural vbraton by multple-mode lqud damper Engneerng Structure Lamb H (193) Hydrodynamc Cambrdge Unverty Pre: London N K Ra et al. (013) Tuned lqud lohng water damper: A robut devce for emc retrofttng Internatonal journal of Envronmental cence: Development and Montorng 4 Nanda B (010) Applcaton of tuned lqud damper for controllng tructural vbraton M. Tech the ubmtted at NIT Rourkela Nomura T (1994) ALE fnte element computaton of fludtructure nteracton problem Computer Method n Appled Mechanc and Engneerng Okamoto T and Kawahara M (1990) Two-dmenonal lohng analy by Lagrangan fnte element method Internatonal Journal for Numercal Method n Flud Srvatava Naln (007) Repone control of tall buldng ung tuned lqud damper M. Tech the ubmtted to IIT Kharagpur Sun L M and Fujno Y (1994) A em analytcal model for tuned lqud damper (TLD) wth wave breakngjournal of Flud and Structure Tat M J, Damatty A A and Iyumov (005) An nvetgaton of tuned lqud damper equpped wth dampng creen under D exctaton Earthquake Engneerng and tructural Dynamc Tamura Y et al. (1995) Effectvene of tuned lqud damper under wnd exctaton -Engneerng tructure Wakahara T, Ohyama T and Fuj K (199) Suppreon of wndnduced vbraton of a tall buldng ung tuned lqud damper Journal of Wnd Engneerng and Indutral Aerodynamc