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Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
Pbwe fp palmeri_barbato
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Pbwe fp palmeri_barbato

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  • 1. Performance-based wind design oftall buildings equipped withviscoelastic dampersFrancesco Petrini*, Alessandro Palmeri, Michele Barbato*Associate Researcher, francesco.petrini@uniroma1.itSapienza – University of RomeDepartment of Structural and Geotechnical EngineeringPerformance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampers
  • 2. Performance-Based WindEngineering (PBWE) procedureIntro
  • 3. Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersUncertainty in Wind EngineeringF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itPetrini F.(2009). “A probabilistic approach to Performance-Based Wind Engineering”, Ph.D. dissertation, department ofStructural and Geotechnical Engineering, Sapienza University of Rome, Rome, ItalyENVIRONMENTWindactionStructuralsystemsNonenvironmentalactionsEXCHANGE ZONESite-specificWindAerodynamic andaeroelasticphenomenaWind sitebasicparametersEnvironmentaleffects (e.g.waves)Structuralsystem as modifiedby service loadsSTRUCTURAL SYSTEMVmMean wind velocity profileVm+ v(t)Turbulent wind velocity profileriverVmMean wind velocity profileVm+ v(t)Turbulent wind velocity profileriverriverENVIRONMENT EXCHANGE ZONE3
  • 4. Uncertainty Propagation in Wind EngineeringPerformance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itTypes of uncertaintiesENVIRONMENTWindactionStructuralsystemsNonenvironmentalactionsEXCHANGE ZONE1. Aleatory2. Epistemic3. ModelInteractionparametersStructural parametersSite-specificWindAerodynamic andaeroelasticphenomenaWind sitebasicparametersIntensity measure1. Aleatory2. Epistemic3. Model1. Aleatory2. Epistemic3. ModelEnvironmentaleffects (e.g.waves)Structuralsystem as modifiedby service loadsIM IP SPSTRUCTURAL SYSTEMSPPIMPSP,IMIPPSP,IP,IMPPetrini, F. & Ciampoli M., 2012, Performance-based wind design of tall buildings, Structure & InfrastructureEngineering, 8(10), 954-966.4
  • 5. PBWE FrameworkPerformance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itOf(IM|O)f(IM) f(IP|IM,SP)f(IP)f(EDP|IM,IP,SP)G(EDP)f(DM|EDP)G(DM)f(DV|DM)G(DV)Hazard analysisInteractionanalysisStructural analysis Damageanalysis Loss analysisIM: intensitymeasureIP: interactionparametersEDP:engineeringdemand param.DM:damagemeasureDV:decisionvariableSelectO, DO:locationD:designEnvironment infoDecision-makingDf(SP|D)f(SP)StructuralcharacterizationSP:structuralsystem parametersStructuralsysteminfoG(DV) = ∫…∫ G(DV DM) · f(DM EDP) · f(EDP IM, IP, SP) · f(IP IM,SP) ·· f(IM) · f(SP) · dDM · dEDP · dIP · dIM · dSPInteractionParametersStructuralParametersIntensitymeasure IM IPSPEngineeringDemandParametersEDPDamageMeasure DMDecisionVariable DVCiampoli M., Petrini F., Augusti G., (2011). “Performance-Based Wind Engineering: towards a generalprocedure”, Structural Safety, 33 (6), 367-378G(·|·) is a conditionalcomplementarycumulativedistribution functionf(·|·) is a conditionalprobability densityfunction= progress with respect to thePerformance-Based Seismic Design** *Extension of thePerformance-BasedSeismic Designprocedure proposed byPEER Research center5
  • 6. Models for tall buildings andserviceability assessment1
  • 7. Serviceability of tall buildings under windPerformance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itTamura, Y. (2009). Wind and tall buildings, Proceedings of the Fifth European & African Conference on Wind Engineering (EACWE5), Florence, Italy, July 19-23, 2009..Loss of serviceabilityLossofintegrityofnon-structuralelementsMotionperceptionbybuildingoccupantsDisplacementsAccelerationsw(t;z2)Vm(z2)Vm (z1)Vm (z3)V(t;z2)v(t;z2)u(t;z2)XZYθB1B2H7
  • 8. Past studies (I): Case studyPerformance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itLoss of serviceabilityLossofintegrityofnon-structuralelementsMotionperceptionbybuildingoccupantsDisplacementsAccelerationsG(EDP) = ∫…∫ G(EDP IM, IP, SP) · f(IP IM,SP) · f(IM) · f(SP) · dIP · dIM · dSPReduced formulationStructure• 74 floors• Height H=305m• Footprint B1=B2=50mFE ModelApproximately• 10,000 elements• 4,000 nodes• 24,000 DOFscentralcore3dframeontheexternalperimeterBracingsystemw(t;z2)Vm(z2)Vm (z1)Vm (z3)V(t;z2)v(t;z2)u(t;z2)XZYθB1B2H8
  • 9. (dr)9Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itLoss of serviceabilityLossofintegrityofnon-structuralelementsMotionperceptionbybuildingoccupantsDisplacementsAccelerationsdr samplesMean valuesmean st devLimit value10-4 10-2 1001010105100ExperimentalAnalyticaln [Hz]PSD[N2/Hz]Vortex shedding effectG(dr|θ=0,ξ=0.4%) (dr)Annual occurrenceMax drift samplesPast studies (II): integrityw(t;z2)Vm(z2)Vm (z1)Vm (z3)V(t;z2)v(t;z2)u(t;z2)XZYθB1B2HCiampoli M, Petrini F. (2011). “Performance-Based Aeolian Risk assessment and reduction for tall buildings”, Probabilistic EngineeringMechanics, 28, 75–84.
  • 10. 10Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itw(t;z2)Vm(z2)Vm (z1)Vm (z3)V(t;z2)v(t;z2)u(t;z2)XZYθB1B2HLoss of serviceabilityLossofintegrityofnon-structuralelementsMotionperceptionbybuildingoccupantsDisplacementsAccelerationsThis paper: tall buildings and viscoelastic dampers[2] Carassale, L., Piccardo, G., Solari, G. (2001), Double modal transformation and wind engineering applications, Journal of EngineeringMechanics 127 (5), pp. 432-439, 2001.Equivalent cantilever beam model (1))(),()(),()(),(2222hSHVchSHhSuumxDDDrr tttt202220220224111)(mHFrequency domain responseStructure Wind0.0025 Hz 0.132 Hz 0.263 Hz1st2nd3rdHeight(m)Height(m)Height(m)Double-modaltransformation (2)[1] Chrysanthakopoulos, C., Bazeos, N., Beskos, D.E. (2006). Approximate formulae for natural periods of plane steel frames. Journal ofConstructional Steel Research 62: 592-604Structure Wind2002121121421)(jjjjjfffiffifiafifHjjjjffifffH022022141)(Frequency response function inpresence of viscoelastic dampersAssumption: devices are uniformly distributedwith the structural stiffness
  • 11. Methodology, case study, results2
  • 12. 12Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itCase-study and structural modeling techniqueEquivalent cantilever beam modelChrysanthakopoulos, C., Bazeos, N., Beskos, D.E. (2006). Approximate formulae for natural periods of plane steel frames. Journal ofConstructional Steel Research 62: 592-604ColumnsHEB45025@3m=75m7 @ 4m = 28mBeams IPE 550Diagonals UPN 140zx
  • 13. ωfexpωSωSωS jkuuuuuu kkjjkjkj2kj2zjkzVzV2πzzCωωf5.00uu2xu200300(x)dxRu1Lzwhere:5/3jujux2uuu/zLf10.3021ω/2π/zLfσ6.686ωS jj2fri02u u1.75)log(zarctan1.16σ)z(V2πzωfjmj13Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersAnalytical model of the wind turbulenceDynamic response in the frequency domainSpectral proper transformationdIMIMpIMEDPGEDPGPerformance evaluation (M.Carlo)2002121121421)(jjjjjfffiffifiafifHPresence of viscoelastic dampersReducedformulationAssumption: devices are uniformly distributed with the structuralstiffnessτ1 = relaxation timea1j = associated viscoelastic stiffness in the jth mode of vibration
  • 14. 14Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itSingle structural analysis (I): eigenvectorsStructure Wind0.0025 Hz 0.132 Hz 0.263 Hz1st2nd3rdHeight(m)Height(m)Height(m)
  • 15. 15Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itInteraction between the wind and the structure (without devices)Structure Wind0.0025 Hz 0.132 Hz 0.263 Hz1st2nd3rdHeight(m)Height(m)Height(m)k=1k=2k=31st 2nd 3rd 4th 5thStructural frequencies Vs Wind power spectra Cross-modal participation matrixNhMjPjhjqh,,2,1122MjdfffDfHwjNnNknkjkjP,,2,1)(1 1222Standard dev of the structural displacementsNormalized mode shapesSpectral eigenvaluesfkhj
  • 16. 16Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itParametric analysis for device parameters0.5 s1.01.52.0Uref=15 m/sNo dissip5 m/s 10 m/s 15 m/s 20 m/sτ1=2.0 s5 m/s 10 m/s 15 m/s 20 m/s2002121121421)(jjjjjfffiffifiafifHFrequency response function in presence ofviscoelastic dampersAssumption: devices are uniformly distributed with the structuralstiffnessA parametric analysis has been conducted in orderto assess the optimal value of the parameter τ1. a1,jhas been fixed equal to 5*(2πfj)2-50%Effect of viscoelastic dampers
  • 17. 17Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itStructural performance assessmentdIMIMpIMEDPGEDPGThe standard deviation of the displacement at the top of the building is assumed as EDP, while the wind speed at10m of height from the surface (U10) is chosen as IM.A Weibull distribution with shape and scale parameter 2.02 and 6.2 is adopted for U10.A total of 500 samples have been generated for evaluating the risk curves G(EDP) for the structure both with andwithout the presence of dissipative devices.
  • 18. 18Performance-basedwinddesignoftallbuildingsequippedwithviscoelasticdampersF. Petrini. Performance-based wind design of tall buildings equipped with viscoelastic dampers.ICOSSAR 2013, Columbia University, New York, 16-20 June 2013francesco.petrini@uniroma1.itConclusions• The adopted analytical methods are very efficient in terms of computationalcosts, especially if the analysis are performed in the frequency domain.• The use of viscoelastic dampers seems to be very efficient in reducing thedisplacements of the building under wind.• Further investigations are required to assess the impact of differentassumptions in the analysis process, namely:• i) neglecting the damping coupling between different modes of vibration(i.e., assuming classical damping);• ii) having more random variables (e.g., the structural damping, theviscoelastic damping, the drag coefficients);• iii) selecting different engineering demand parameters (EDPs), associatedwith various limit states;• iv) developing the necessary steps for the evaluation of probabilisticevaluation of the performances in monetary terms (loss analysis).ACKNOWLEDGMENTSThe first author would like to acknowledge the financial support by StroNGER s.r.l. from thefund “FILAS - POR FESR LAZIO 2007/2013 - Support for the research spin-off”

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