简介:Thisstudyinvestigatestheeffectivenessofthenon-smoothsemi-activecontrolalgorithmonsuppressingthevibrationperformanceofabuildingstructuresubjectedtoseismicwaves.AccordingtotheLyapunovstabilitytheory,ithasbeneproventhatthenon-smoothsemi-activecontrolalgorithmcanachieveafinite-timestabilityofthevibrationrelativetotheisolationlayerofabuildingstructure.Throughnumericalsimulationoftwobuildingswithdifferentparameterssubjectedtotheinputofaseismicwave,thevibrationconditionsofpassivecontrol,LQRsemi-activecontrolandnon-smoothsemiactivecontrolarecomparedandanalyzed.Thesimulationresultsshowthatthenon-smoothsemi-activecontrolalgorithmhasabetterrobustnessandeffectivenessinrestrainingtheimpactofearthquakesonthestructure.
简介:Two-monthcontinuouswaveformsof108broadbandseismicstationsinFujianProvinceanditsadjacentareasareusedtocomputenoisecross-correlationfunction(NCF).ThesignalqualityofNCFisimprovedviatheapplicationoftime-frequencyphaseweightedstacking.TheRayleighandLovewavesgroupvelocitiesbetween1s-20saremeasuredonthesymmetricalcomponentoftheNCFwiththemultiplefiltermethod.Morethan5,000Rayleighwavedispersioncurvesandabout4,000Lovewavedispersioncurvesareobtainedandusedtoinvertforgroupvelocitymaps.Thisdatasetprovidesabout50kmresolutionthatisdemonstratedwithcheckerboardtests.Consideringtheoffgreatcircleeffectininhomogeneousmedium,theraypathistracedbasedonthetraveltimefieldcomputedwithafinitedifferencemethod.Theinvertedgroupvelocitymapsshowgoodcorrelationwiththegeologicalfeaturesintheupperandmiddlecrust.TheFuzhoubasinandZhangzhoubasinshowedlowvelocityontheshortperiodgroupvelocitymaps.Onthelongperiodgroupvelocitymaps,thelowvelocityanomalyinthehighheatflowregionnearZhangzhouandclearvelocitycontrastacrosstheZhenghe-Dapufaults,whichsuggeststhattheZhenghe-Dapufaultmightbeadeepfault.
简介:Inthisresearch,thevibrationofelevatorropes,includingthemainropeandcompensationropeareinvestigatedsimultaneouslyinahigh-riseelevatorsystemunderearthquakeexcitation.Moreover,thepaperpresentsanewcontrolmethodtorestraintheswayofbothropes.Thisstudyconsidersvaryingropelengthsduringelevatoroperationwhichcauseothersystemparameterssuchasnaturalfrequency,anddampingratiotobetime-variantvariables.Thedynamicsoftheropesareanalyzedbysolvingthegoverningnon-stationary,nonlinearequationnumerically.Inordertomitigatethevibrationofropesinseveralmotionconditions,particularlyupwardsmovement,downwardmovement,stoppedatthelowestposition,andstoppedatthehighestposition,anactiveequipmentisinstalledatthecompensationsheave.Thestabilityofthesystemusingthecontrollerisanalyzedatfourstates:withoutdisturbanceandstaticcar,withoutdisturbanceandmobilecar,includingdisturbanceandstaticcar,andincludingdisturbanceandmobilecar.Theefficiencyofthecontrollerusedfordampeningthevibrationofelevatorropesisvalidatedbynumericalsimulationresults.