Performance Evaluation of atall Building with Damped Outriggers Ping TAN

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1 Performane Evaluation of atall Builing with Dampe Outriggers Ping TAN Earthquake Engineering Researh an Test Center Guangzhou University, Guangzhou, China

2 OUTLINES RESEARCH BACKGROUND IMPROVED ANALYTICAL MODEL 3 PARAMETRIC ANALYSIS 4 SHAKING TABLE TEST 5 CONCLUSIONS

3 . RESEARCH BACKGROUND In 7, Rob Smith an Mihael Willfor put forwar onept of the ampe outrigger layout of amper

4 . RESEARCH BACKGROUND Suessfully applie to two m high builings in Philippine Only 6 ampers use to provie aitional 5.% amping level onstrution ost saving was nearly $5 million St Franis Shangri-La Plae

5 . RESEARCH BACKGROUND In 8, Gamaliel R. ompare two onfiguration of amper, series an parallel with perimeter olumn ue to win effet. In 9, Chen et al. evaluate moal amping ratio using virtual work priniple. In, Wang et al further extene to MR with lippe optimal ontrol an LQG algorithm aopte. In, Chen et al. theoretially erive an expliit form for the omplex frequeny an provie the optimal amper position an size. In, Zhou et al. explore seismi performane of a supertall builing with ampe outriggers onsiering five onnetion types of visous amper. In 3, Chang et al. investigate seismi mitigation of MR installe in St. Franis Shangri-La Plae in Philippines.

6 . RESEARCH BACKGROUND Existing problem: To ate, theoretial analysis of suh novel energy issipating system is quite rare Previous analytial moel is not aurate, stiffness of outer olumns is assume to be infinitely rigi No attempt is mae to investigate the parametri optimization of this novel ampe outrigger system. An improve analytial moel for the ampe outrigger is require to provie general guiane in preliminary esign in terms of the moal amping ratio, the installe ampers, the optimal ampe outrigger position an the stiffness ratio of the ore to the olumn.

7 . IMPROVED ANALYTICAL MODEL Fig. Current analytial moel (Taranath,975) Fig. Improve analytial moel A rotational spring aount for the effets of outrigger an ae ampers. It an be use for both the traitional an the ampe outrigger system

8 . IMPROVED ANALYTICAL MODEL Equivalent rotational spring stiffness Damper in series with perimeter olumn Axial stiffness of outer olumn Resistant moment Equivalent rotational stiffness M k Equivalent stiffness kr i k EA L eq eq F r k ur k kic ( r ) r k ic k C ic kic ic

9 . IMPROVED ANALYTICAL MODEL Non-imensional parameters 4 4 ml EI M k ic w ( ) ri( )( ) EA EI L mei i( L p i EA EI L mei L L m r L L )( m r ) EI ( i ) EI ks L w Cr L me I w w p EI w w E A r Substitution into resistant moment kr ic =: a bare outrigger where k s i p i an p : traitional outrigger system The ampe outrigger system an the traitional outrigger system are unifie in this improve moel.

10 . IMPROVED ANALYTICAL MODEL This improve analytial moel is very simple, aurate an easy for theoretial analysis. Both the traitional outrigger system an the ampe outrigger system are unifie in the propose analytial moel. The axial stiffness of the peripheral olumns an outrigger are uner onsieration (a) Two ampe outriggers (b) One ampe outrigger at lower level General rotational stiffness () One ampe outrigger at top () Two unampe outriggers Fig. ifferent ombinations of ampe an unampe outriggers in a builing.

11 . IMPROVED ANALYTICAL MODEL Dynami stiffness methos(dsm) use to formulate the governing equation of the ampe outrigger system 4 y( x j, t) y( x j, t) EI m 4 xj t The solution to the partial ifferential is assume to have the form of y( x, t) Y( x ) e it j Y j A j A j j ( ) osh( ) sinh( ) A3os( j) A4sin( j) Relationship between en fores an en isplaements EI k k k k k k ( ) () ( ) () ( ) ( ) 3 4 k k k k k k k ( ) () ( ) () ( ) ( ) s 4 4 L k k k k 3 ( ) ( ) ( ) ( ) 3 4 k k k k ( ) ( ) ( ) ( ) 4 4 L b L b K

12 . IMPROVED ANALYTICAL MODEL Dynami harateristi equation i{[os( )sinh( ) sin( )osh( )] [ os( )osh( )] [os( )sinh( ) sin osh( )] [ os( )osh( )] p[os( )osh( ) ]} [os( )osh( ) ] One the above Eq. was solve, the omplex frequenies EI i i 4 n i n ml pseuo-unampe natural irular frequeny n i moal amping ratio Re( i) n

13 . 3. PARAMETRIC ANALYSIS Stiffness ratio of ore to perimeter olumn st moe n moe 3r moe P= P= the number of peak is equal to the moe orer The first moal amping ratio is higher than the other. two moes

14 PARAMETRIC ANALYSIS Stiffness ratio of ore to perimeter olumn st moe n moe 3r moe.4. P= P= Similar teneny for ifferent p

15 3. PARAMETRIC ANALYSIS Stiffness ratio of ore to perimeter olumn m.5.3. =.55 = p It is suggeste that p shoul not be larger than 4 to ahieve supplementary 5% amping level.

16 3. PARAMETRIC ANALYSIS Optimal position of ampe outrigger st moe n moe 3r moe p= p=.5 p= p= p= p= p=.5 p= p= p= p= p=.5 p= p= p= m.5 m.3 m There are one, two an three peaks for the first, seon an thir moe, respetively. Optimal position of ampe outrigger is ifferent with moe orer. The moal amping level rops with inreasing p.

17 opt 3. PARAMETRIC ANALYSIS Optimal position of ampe outrigger p= p=.5 p= p= p= 4.6 opt Optimal position of ampe outrigger for a given of the first moe Optimal position beomes lower as p or inreases. Optimal position of ampe outrigger is ifferent from the traitional outrigger.

18 3. PARAMETRIC ANALYSIS Optimal amping oeffiient st moe n moe 3r moe p= p=.5 p= p= p= p= p=.5 p= p= p= p= p=.5 p= p= p= 4 m.6.5 m.3 m Optimal moal amping ratios versus amping oeffiient Too muh amping just leas to averse effet. The optimal amping oeffiient shoul math with the quantity of p.

19 3. PARAMETRIC ANALYSIS Optimal amping oeffiient.4. p= p=.5 p= p= p= opt Optimal amping for a given ampe outrigger position of st moe opt Optimal amping of ampe outrigger varie with p of st moe p The optimal amping oeffiient beomes lower as α inreases. the optimal amping oeffiient ereases with inreasing p

20 3. PARAMETRIC ANALYSIS The optimal amping oeffiient shoul math with the quantity of p. In orer to ahieve a greater amping level for the appropriate number of ampers, it is neessary to inrease the outrigger span or the axial stiffness of the perimeter olumns an reue the bening stiffness of the ore

21 4 SHAKING TABLE TEST Plan:6 4mm Visous Dampers Height:7mm,8 stories height-to-with Ratio:8 Outriggers : 4 th, 8 th Material:Q345 steel Core:mm 4mm Column:5mm 5mm Floor:mm Test Moel Thik onrete blok: 8 kg

22 4 SHAKING TABLE TEST u( t) sgn( ) 5.3 Fore-Veloity relationship of visous amper Bilinear tren The measure are in agreement with the theoretial parameters

23 4 SHAKING TABLE TEST Dynami properties of the test moel with fixe an ampe outriggers Moel Funamental perio (s) Damping ratio Fixe- Outrigger Dampe- Outrigger A sine sweep vibration test is onute to searh for the natural perios an amping ratio of Fixe the test moels Dampe Both funamental perio an amping ratio of the ampe outrigger are inrease, an the inrease in amping ratio is muh higher

24 4 SHAKING TABLE TEST Aeleration g g.6g Input Groun Motions: El Centro (94, NS) Hollywoo (97, NS) Peak abs. aelerations of the ampe ase are reue signifiantly as ompare to the fixe ase better performane oul Aeleration(g) be ahieve Aeleration(g) with the inreasing Aeleration(g) PGA of groun motions. F-El F-H D-El D-H F-El F-H D-El D-H F-El D-El F-H D-H Story aeleration envelope

25 4 SHAKING TABLE TEST Drift g g.6g as ompare to the fixe ase. Drift(mm) 4 Peak interstory rift of the fixe ase are reue signifiantly better performane oul be ahieve with the inreasing PGA of groun motions Drift(mm) Drift(mm) 4 3 F-El F-H D-El D-H F-El F-H D-El D-H F-El D-El F-H D-H Interstory rift envelope

26 4 SHAKING TABLE TEST Aeleration(g) Displaement(mm) El Centro, PGA =.6g.5 Dampe Fixe 4 3 Dampe Fixe Time(s) Roof aeleration Time(s) Roof isplaement both roof aeleration an roof isplaement of the ampe outrigger system are muh lower. The ampe outrigger system an make full use of ampers an greatly enhane the safety of the struture.

27 5. CONCLUSIONS The ampe outrigger system offers a ost-effetive means for high-rise builing. Shaking table test results verify the avantage of the ampe outrigger over the fixe ase. An improve analytial moel of the ampe outrigger system is evelope. The ampe outrigger system an the traitional outrigger system are unifie in this improve moel. In orer to ahieve a greater amping level, The optimal position shoul math with the optimal strutural parameters an amping oeffiient. Supplementary moal amping ratio is more sensitive to amper amping oeffiient than the position of ampe outrigger.

28 THANK YOU FOR YOUR ATTENTION!

Optimum design of tuned mass damper systems for seismic structures

Optimum design of tuned mass damper systems for seismic structures Earthquake Resistant Engineering Structures VII 175 Optimum esign of tune mass amper systems for seismic structures I. Abulsalam, M. Al-Janabi & M. G. Al-Taweel Department of Civil Engineering, Faculty