涡轮机械叶片振动测量的实验研究

PAGE5PAGE2ANEXPERIMENTALSTUDYONBLADEVIBRATIONMEASURMENTSINTURBOMACHINERYCONTENTS PageNo.1.ARABICABSTRACT…………….…………….32.ENGLISHABSTRACT………...43.INTRODUCTION……...……...…5 4.LITERATURESURVEY……….6 4.1.VibrationMeasurementsinTurbo-Machinery………..……8 4..2.VibrationofBladesinTurbo-Machinery….10 4.3.MeasurementsofBladeVibrations…………….…………125.CURRENTSTATUSOFTHEPROBLEM……..…………136.OBJECTIVESOFTHESTUDY……………….……..….……167.UTILIZATION…….……..…..…178.PROJECTDESIGN……………………..……...188.1.Test-Rigdesign…………………18 8.2.Test-Rigassemblyandpilottesting.………….18 8.3.FreeandForcedVibrationexperiment……….19 8.4.ExperimentsonRotatingunit………………….20 8.5.DiscussionandReportWriting………………..209.TEST-RIG&MEASURINGEQUIPMENT………………….209.1.In-houseEquipment……………...21 9.2.NewEquipment…………………..2210.PERSONNELREQUIRMENT………………2211.PROJECTSCHEDULEANDMANAGEMENTPLAN……2312.PROJECTBUDGET………….2413.REFERENCES………………...25APPENDIXA:PreliminaryTest-rigdesignandMeasurements………………28 ABSTRACTTheproposedstudyaimsatdeveloping,experimentally,acorrelationbetweentherotatingbladeandshaftvibrationsinturbomachineryandjet-engines.Thestudywillinvestigateexperimentallythebasicproblemofdynamicinteractionbetweenbladeandshaftvibrations,whichisnotyetsatisfactorilyunderstood,duetothedifficultiesinmeasuringtherotatingbladevibrations.Theimportanceofthisproblemhasdevelopedoveryears,asitiswellknownthatbladevibrationisoneofthemaincausesofthecostlyfailuresinturbomachineryandjet-engines.However,littleprogresshasbeenfoundduetothefactthatbladesarerotatinginerosiveenvironmentandtheirvibrationsareextremelyhardtomeasure.Thisstudyproposesmeasuringtherotatingbladevibrationsthroughshafttorsional/lateralvibrationmeasurements,basedontherecenttheoreticalfindingsonthestrongdynamicinteractionbetweenbladeandshaftvibrations.Atest-rigthatallowsmeasuringbladeandshaftvibrationswillbedesignedandmanufacturedfortheproposedstudy.Therotatingbladevibrationswillbemeasuredusingstraingageswithwirelesstelemetrysystem.TheshafttorsionalvibrationsaregoingtobemeasuredusingtheLaser-torsionalvibrationpick-upwhichhasshowngreatsuccessinthisregard.Theshaftlateralvibrationswillbemonitoredusingbothproximityprobesandbearingaccelerometers.Differentdataprocessingtechniqueswillbetriedforthepresentstudytoenableextractingreliablebladevibrationsignalsandtosupportdevelopingthetheoryofblade-shaftdynamicinteraction.Parametricstudywillbeconductedoncombinationsofblade/shaftproperties.Theresultswillbestudied,discussed,andconclusionswillbedrawn.Theoutcomeexpectedfromthisstudy,isnotonlyvaluablefordiagnosticsandmaintenancepurposes,butalsoforthebasictheoryofrotordynamicsthatisvitalinthedevelopmentanddesignstagesofrotatingmachinery.3.INTRODUCTION Rotatingmachineryisthebackboneelementinpowergeneration,oil-processingandaeropropulsionindustries.Onemaincauseofthecostlyfailureofrotatingmachineryistheproblemofvibration.Machinerymalfunctiondiagnosisandcorrectionmethods,usingvibrationmeasurementandanalysis,havebeendevelopingoveryearsduetotheincreasingneedforrunningmoreefficientmachines,athigherspeedswithlessshutdowntime,lessmaintenancecostandstrictsafetyrequirements.Malfunctiondiagnosisdependsontheunderstandingofthephysicalphenomenaofvibrationinrotatingmachinesandontheprocessofvibrationmeasurement.ThedevelopmentsinthebasictheoryofrotordynamicsandinthevibrationmeasurementtechniqueshaveresultedinperiodicandpermanentdiagnosisprogramswheresavingsofmillionsofUSdollarshavebeenreportedintheUnitedStatesonlyduetoadoptingthesediagnosisprograms. Atypicalturbomachineryiscomposedofmanycomponentssuchasshafts,disks,bearings,gears,couplings,blades,housingandfoundation.Someofthesecomponentsvibrationproblemshavebeendealtwithsatisfactorilyduetothedevelopmentintheirvibrationmeasurementtechniquesandtheprogressinunderstandingthephysicalphenomenathroughlaboratorytestingandmathematicalmodeling.Examplesofthesecomponentsarethemainshafts,bearingsandgears.Onebasiccomponentinturbomachineryistherotatingbladethathasbeenrecognizedasonemajorcauseoffailureinmanygasturbinesandjetengines.Bladesare,usually,rotatingathighspeeds,interactingwiththeerosiveenvironmentatelevatedtemperaturesandhavecomplicatedshapestomaximizetheirfluidhandlingefficiency.Theseoperatingconditionsexposethebladestomanyvibrationexcitationmechanismsandinthesametimemakethevibrationmeasurementprocessofbladesaverycomplicatedproblem.Thedifficultiesinmeasuringbladevibrationhaveallowedlittleprogressintheunderstandingofbladevibrationphenomenonanditsinteractionwiththeothercomponents,despitethetheoreticalandnumericalachievementsinthisdirection.Furthermore,thesedifficultiesusuallycontributetoproducingproblemsinthediagnosticprocessesduetoabsenceofbladesvibrationhistoryandtheuncertaintyontheirinvolvementinthemachinerymalfunction.Onealternativeapproachforbladevibrationmeasurementistheindirectapproachthroughmeasuringthevibrationsofmachinecomponentsthatareknowntohaveastrongdynamicinteractionwiththeblades.Themainshafttorsionaland/orlateralvibrationareknowntohavestrongdynamicinteractionwithbladesvibrations.Thevibrationmeasurementofshafttorsionaland/orlateralvibrationsisexpectedtoprovideagoodmeasuringtoolforbladesvibrationwiththeaidofsomesignalprocessingtechniques.4LITERATURESURVEY4.1.VibrationMeasurementsinTurbo-machineryVibrationmeasurementsinturbo-machineryhavebeenidentifiedasanextremelyvaluabletoolfordevelopment,diagnosticsandmaintenanceprograms.LawsandMuszyynska[1]havereportedtheimportanceofvibrationmeasurementforperiodicandcontinuosmonitoringforPreventive/Predictivemaintenanceprograms.Intheirpaper,LawsandMuszynska[1]describedthedevelopmentinthemaintenanceprograms,startingformthedayswhenthemachineoperatorusedtolistentothemachineryandtouchesbyhisfingerthebearingcap,inordertoidentifymachineproblems.Reference[1],includedadetaileddescriptionofmaintenancesystems,categorisedthePredictive/Preventivemaintenanceprograms,andaddressedtheimportantissuesofpick-upsselectionanddataprocessing.Basedontheirexperiencewiththeindustrialworld,LawsandMuszyynskaconcludedthatthecostofimplementationofPreventive/Predictivemaintenancesystemsislesscostlythanthemachinefailure,whichisknowntobeexpensiveintermsoflossinproductionbyshutdowntime,componentsdamages,andmostimportantaspectinjuriesofpersonnel.Vibrationmeasurementhasbecomeanessentialtoolforanyengineerwhoisinvolvedwithturbo-machinerydevelopment,commissioning,maintenanceandoperation.Thisnecessityhasenforcedtheinclusionofvibrationmeasurementtechniquesinmanybooksthataddressrotordynamicsproblems.Vance[2]inhisbookaddressedthebasicsofrotordynamicsofturbo-machineryandincludedachapteronvibrationmeasurementinturbo-machinery.Inthischapter,theprocessofvibrationmeasurementisdividedintothemainpartsofpick-upsanddataprocessingofthemeasuredsignals.Themajorvibrationpick-ups;proximityprobes,velocitymetersandaccelerometersarestudied.Specialattentionwasgiventotheproblemoftorsionalvibrationsofshafts,duetothedifficultyinsensingtorsionalvibrationsignals.Inthisdirection,Vance[2]discussedtheavailablemethodsfortorsionalvibrationmeasurementsandconcentratedonthestraingagesandtheTimeIntervalMeasurementMethod,whichisanopticalmethodthatdependsmoreonthesignalprocessing.Whenbladesandvanesvibrationswerementioned,Vance[2]statedthat“thesevibrationsaredifficulttodetectanddifficulttoquantify”.Vance[2]addedthatthe“Dopplerdetectiontechniquesshowpromisebuthavenotbeensufficientlydevelopedforpracticaluse”.AbookbyGoodwin[3]hasincludedchapteronmeasurementsfortherotor-bearingssystems.Inthisbook,thetraditionalpick-ups,proximityprobes,velocitymetersandaccelerometerswerecovered.Thisbookcanbecategorisedintomorediagnosticsthanmeasurementtools,inparticularpick-upsandtransducers.Morerecentbooksintheareaofmachineconditionmonitoringandvibrationmeasurements,[4],includenothingaboutthepick-upsfortorsionalandbladevibrationsinrotatingmachinery.Thisisnotbecausetheyareoverlookingthisbasicandimportantpart,butbasedonthefactthatpickupsandtransducersforthesetwotypesofvibrationsarestillwithinresearchanddevelopmentstages.SimmonsandSmalley[5]havedescribed,inaninterestingmanner,theeffectivetoolsfordiagnosingelusiveturbo-machineryproblemsinthefield.Theycategorisedthevibrationsencounteredingasturbinesintomainly:(1)Torsionalvibrations,(2)Lateralrotordynamics,(3)Bladevibrations,(4)Compressorstalland(5)burnerandCombustorvibrations.Theydescribeeachgroupintermsoftheavailabletransducers,causesandqualitativedescription.Whenbladevibrationswasaddressed,SimmonsandSmalley[5]havestatedthat“bladevibrationsaremajorsourceofcostlyproblemsingasturbinesandcanariseforvariousreasons”.Theyaddedthat“afrustratingfactaboutbladevibrationsisthedifficultyofmakingdirectmeasurements-bladesarerotatingandofteninahotanderosiveenvironment’.Theyreportedthatstraingagesmeasurementarerarelyattemptedastheyareexpectedtolastforlimitedtime.Theyconcludedtheirpaperbystatingthatbladevibrationsarethemostcostlycauseofturbineoutageandrepaircostandanymonitoringprogram,exceptsometimestoindicatethatthebladefailurehasoccurred,doesnotyetaddressthem.Theyfurtheraddedthatnon-contactmethodsofbladevibrationmeasurementsarestartedtocomeintothesurfaceandshowpromises.4.2.VibrationofBladesinTurbo-machineryTheproblemofbladevibrationshasbeenrecognisedasonemajorandcostlycauseofturbo-machineryfailures.Duetotheresearcherandthedesignerknowledgeofthecomplexitiesinbladevibrationmeasurements,theoreticalandnumericalstudieshavebeenproposedtomakesurethatthedesignedbladewillnothaveresonanceconditionswithinthemachinespeedrange.Despitethegoodnumberofresearchpaperspresentedinthefamoussymposiumonrotordynamics[6],onlyonenumericalpaperonbladevibrationswaspresented.Thereasonisthatpeoplewereattractedmoretowardsthebasicdynamicalbehaviourofrotors,asitwasnotyetestablished.Withtheincreasingtrendofoperatingsystemsathigherspeedswithmoreloadsandmoresevereenvironment,theimportanceofstudyingandmonitoringbladevibrationshasbeenfurtherrecognisedandmoreattentionwasdirectedtoit.Comprehensive,numericalmodelsthataddressbladevibrationsandbladestressesarepublishedinthelasttwodecades,duetheprogressincomputersandmicroprocessors.Aliteraturesurveyonthevibrationsofbladed-diskassemblieswasreportedbySrinivasan[7].Inthissurvey,hehighlightedtheimportanceofmodellingthedisk-bladevibrationsandclassifiedthevibrationsintotwomaincategories;namelystructureinducedvibrationsandaero-elasticinducedvibrations.Moreattentionwasgiveninthissurveyforstructuralinducedvibrations.Otherstudiesweredevotedtotheinteractionbetweenthebladevibrationsandtherotordynamics[8and9].Intheworksofreferences[8]and[9],theeffectsofshaftbendingvibrations(whirling)onthevibrationsofbladeddiskswerestudied.TheproblemofshafttorsionalvibrationscoupledwiththebladevibrationswasaddressedbyOkabeet.al.[10].Inthispaper,theydevelopedalumpedparametermodelforbladeandshafttorsionalvibrations.Theydividedthesystemintoblade-subsystemandshaft-subsystem;whereinthesimplemass-springsystemmethodisadoptedinbothsubsystems.Thetwosubsystemsthenwerere-coupledandsimulated.Inthesamedirection,HuangandHo[11]reportedresultsofastudyonthecoupledshafttorsionalandbladebendingvibrationsofarotatingshaft–diskbladeunit.Theshafttorsionalandbladebendingdeformationsweremodelledseparatelyusingtheassumedmodesmethod.Theyhaveusedthemethodofweightedresidualsandutilisedthereceptencesattheconnectionbetweenthediskandthebladetocoupletheshafttorsionalandbladebendingdeformations.Theresultsoftheirstudy,intermsofnaturalfrequenciesandmodeshapes,showedcouplingbetweenthebladeandshaftvibrationsandbetweentheindividualblades.Recently,basedionthegeneralmultibodydynamicsapproachAl-Bedoor[12]reportedacoupleddynamicmodelforblade-bendingandshaft-torsionalvibrations.Inthismodelnoseparationbetweenthebladeandshaftmodellingwasneededastheywereconsideredformthebasicgeometricalapproach.Thismodelhaseliminatedanypossibleshortcomingsfromthemodelsof[10]and[11],duetotheartificialcouplingbetweentheshafttorsionalandbladebendingdeformations.Themodelhasprovedthatthecoupleddynamicsofbothshafttorsionalandbladevibrationsshouldbeconsideredwhenaddressingeitheroneofthesevibrationmechanismsinrotatingmachinery.Inthesamedirection,Al-Bedoor[13]hasstudiedtheeffectsofflexiblecouplingsonthevibrationsofbladesinrotatingsystems.Anon-lineardynamicinteractionwasobservedandmoreparametricstudieswererecommended.4.3.MeasurementofBladeVibrationsDuetothefactthebladeisrotating,itsvibrationmeasurementisadifficulttask.However,researchersanddiagnosticsengineershaveutilised,mainly,threeapproachesformeasuringbladevibrations.Thethreeapproachesare:(1)straingagesattachedtotheblade,(2)LaserDopplerandopticalmethods,and(3)indirectmeasurementthroughmonitoringthecasingvibrationsnearbladetips.Despiteitslimitations,themethodthatusesstraingageshaveconvincedmanydiagnosticsengineers,manufacturersandresearchers.KaufmanandKershisnk[14]reportedacasehistoryoffatiguefailureatthebladerootsofanF-18aircraftturboengine.Theyusedsixstraingagesontheandtransmittedthesignalthroughaslipringmechanism.Thesignalhadtobeamplified,conditionedandrecordedonapermanenttapeforfurtheranalysis.Manymodificationsintheenginespecificationsanddimensionshadtobeconductedinordertoinstallthismeasuringsystem.Thislimitstheapproachtoalaboratorytestingandcannotbeusedforactualrunningturbomachinery.Scalzoet.al.[15]reportedastudyfortheanalysisandsolutionofanon-synchronousvibrationprobleminthelastrowturbinebladeofalargeindustrialcombustionturbine.Theyusedstraingagestomeasurebladevibrations.Vibrationssignalsfromstraingagesweretransmittedusingatelemetrysystemastheydecidednottochangetheturbinestructureforusingslipringsandfurtherbecauseslipringsareknowntoproducetoomuchnoiseintothesignal.Theyfacedaproblemofhavingthetelemetrysystemsensitivetohightemperature.Inordertocompensateforthissensitivity,ittookthemthreemonthstodesignacoolingsystemforthetelemetrysystem;forboththetransmitterandtheantenna.Theirstudyhasresultedinasolutionbyre-designingthebladeshape,toremoveconditionsthatledtoseverevibrationsandfatigue.TangandDowell[16]usedstraingagesforbladevibrationmeasurementsintheirexperimentalset-up.Fanetal.[17]reportedtheirexperimentsonthevibrationmeasurementsofrotatingblade.Theyusedarotatingpiezoelectricshakerthatexcitesthebladewhileitsrotating.Atelemetrysystemthatusestransmitterandantennahasbeenutilisedintheirexperiments.Recently,RaoandVyas[18]reportedresultsoftheirtheoreticalandexperimentalstudyonbladestressesunderconstantspeedandtransientconditionswithnon-lineardamping.Theyusedtri-axialsetstraingagesnearthebladerootandtransmittedthesignalthroughslip-ringmechanism.Tothisendonerecognisesthepopularityofstraingagesinmeasuringbladevibrations.Inthesametime,problemsassociatedwithstraingagesuseforbladevibrationsmeasurementscanbeidentified.Amongtheseproblemsare:(1)wheretolocatethestraingagesrosetteswhendealingwithanactualbladewithcomplexshape,(2)whataretheeffectsofactualoperatingconditionslikehightemperatureanderosion,(3)howtotransmitstrainsignaltobefurtherprocessedandstudied,and(4)howlongstraingagesrosettesaregoingtoserve.ThesecondtypewhichisusingLaser-DopplerandOpticalmeasuringmethodshavedevelopedintheearlyeightiesbecauseoftherevolutioninLaserandcomputerapplicationsinmeasurementsystems.CooksonandBandyopadhhyay[19]proposedafibre-opticLaserDopplerprobe,forvibrationanalysisofrotatingmachines.Inthispaper,problemsofstraingagesaredescribedindetail.Themainlimitationontheirstudyisthattheirsystemdependsonfrequencyshiftingtechnique,“Bragcell”,thatlimitedtherotatingspeedthattheirmeasuringsystemcanhandleupto1000rpm,whichislowfortoday’smachinery.Navaet.al.[20]reportedresultsofastudyonusingthefibreopticsensorsonbladevibrationmeasurements.Thesystemusesfouropticalsensingheadstodetectthepassageofeveryblade.Theyhavesimulatedthemeasuringsystemandcomparedtheexperimentalresultswithstraingagesoutput.Theresultisthatinallcasesthevibrationamplitudewasunderestimated.Theyconcludedthatasimulatorcanbeimplementedinthemeasurementsystemtoimproveitsaccuracyandfurtherworkonrefinedalgorithmanddataprocessingtechniquesisrecommended.Inthesamedirection,Reihardtet.al.[21]usedthelaservibrometrymeasurementsystemintheirexperimentalset-up.Intheirsurvey,theyrecognisedhowvitalistheproblemofbladevibrations.Accordingtothem,McCloskey[22]reportedthatturbinebladefailuresaremanycausedbyvibrationrelatedfatiguestressesthatcausedashutdowncostofmorethan$235millionannually,intheUSutilitiesonly.Reihardtet.al.[21]excitedthebladeintheaxialdirectionandrecordedthemeasuredvibrations.Thebladevibrationfrequenciesandamplitudeswereestimatedfromtheleast-squarescurvefittingprocedure.Thistechniquehaslimitedthebladerotationalspeedforwhichatleasttwocompletevibrationcyclestobeobservedbythelaserbeamontheblade.Theyconcludedthatthisposesaseverelimitationontheprocess.Tothisend,theproblemswiththelimitationonthespeedofrotationduetotheneedoftoomanysensorsisclearinthistypeofmeasurement.Themethodispromisingwiththeincreasingprogressintheareaofsignalprocessingtechniques.However,themethodstillhasotherpracticalproblemssuchastheattachmenttotheturboenginecasingandtheexposuretosevereenvironmentintheactualcases.Theapproachofindirectmeasurementshasbeenknownforalongtime,[1],andstillsomeresearchersarefollowingit.Mathiuoudakiset.al.[23]attachedaccelerometersatthecasingofacompressorsnearthebladetips.Theirmainintentionwastomeasurebladevibrations.Theyalsousedpressuretransducersattheinsidefaceofthecasingandusedproximityprobesandkeyphasoratthemainshaft.Thecollectedvibrationsignalsarerichinfrequencycontents.Thismethodhaveshowngreatdealofuncertaintieswhenbladevibrationsaretobemonitored,asaresultofthecontributionofalmostallworkingfluidandmachinetypesofinstabilitiesinadditiontotheacousticalandhousing/foundationproblems.5.CURRENTSTATUSOFTHEPROBLEM Basedontheliteraturesurveyandtheresearchteamcommunicationswithspecialisedpeopleinthefieldofrotatingmachines,measurementsanddiagnostics,thefollowingpoints,regardingbladevibration,haveemerged:Bladevibrationrepresentsoneofthemainfailuremechanismsinturbo-machinery.Theresultinglosses,intermsofshutdown,productionloss,parts,maintenanceandtheimportanthumansafety,arehuge.Theproblemofthedynamicinteractionbetweenbladeandmainshaftvibrationisnotyetsatisfactorilyunderstood,duetotheabsenceofreliableandextensiveexperimentalstudiesonit.Considerationoftheoreticalbladevibrationaspectsinthedesignstagehasbeenprovednotenoughtomakesurethatthebladeisnotonemajorsourceofproblemsinturbo-machinery.Furthermore,measurementofbladevibrationinthedevelopmentstagesisanessentialelementinbladeandwhole-machinedesign,notonlyforoperationanddiagnosticspurposes.Theavailablemethodsofbladevibrationmeasurementare;(1)Straingages,(2)Laser-Dopplerandoptical,(3)theindirectapproach,throughcasingaccelerationmeasurements.Theavailablemeasurementmethodsforbladevibrationshavetheirshortcomingsanddisadvantages.Someoftheshortcomingsanddrawbacksofthesemethodsarelistedbelow:STRAINGAGESMETHODLocatingstraingagesonthebladesurfaceisalwaysaproblem,astheactualshape,profile,ofthebladeiscomplexanditishardtoselectthepointthatrepresentthenormalstrainlocation.Thiswillpreventreflectingtheactualvibrationmechanismoftheblade.Bladesareusuallyoperatinginhightemperatureanderosiveenvironment,whichwilldestroythestraingagesrosettes.Iftobeprotectedbysomecover,theefficiencyofthebladeprofileisgoingtobeaffected.Finally,thedurationofstraingagesserviceisverylimited.Transmittingthevibrationsignalisanotherproblem.Slipringsusuallyproducenoiseforthemeasuredsignal.Telemetrysignaltransmissionhassolvedpartoftheproblem,butstillthewiringfromstraingagestotheTelemetrytransmitterisaproblem.LASER-DOPPLER&OPTICALMETHODLocationsoflaser/opticalsensorsare,mainly,intendedtobeattheinsidefaceofthecasing.Thiswillproducemanyproblems,amongwhichare;(a)theproblemofchangingthefluidpathandthethusthemachineefficiency,(b)thecasingitselfisvibratingthataffectsthesignaltransmitted/receivedfromtheLaser/Opticalsensors.Themethodneedshugenumberofsensors,morethanonesensorforeachblade.Laser-Dopplerandopticalsensorsareusuallysensitiveandexpectednottobeabletowithstandsevereoperatingconditions.Despiteitspromisingnature,themethoddepends,mainly,ondataprocessingtechniquesandhasshownseverelimitationswithregardtothespeedoftherotatingblade.Inotherwords,thespeedofrotationislimitedto1000RPM.THEINDIRECTMETHODThesignalmeasuredusingaccelerometersatthecasingofthemachinecontainsallthedynamicinteractionofthemachine,theworkingfluiddynamicsandtheacousticalwaves,wheresomeofthesedynamicinteractionsarenotunderstoodyet.Extractingusefulinformationonbladevibrationsusingthismethodrequiresacompleteknowledgeofothercontributingfactors,whichisnotavailable.Theavailabledataprocessingtechniquesarenotadvancedenoughtoallowextractingsignalsrelatedtobladevibrationsformtherichsignalofthecasingvibrations.Bynomeans,theavailableindirectmethod,casingvibrations,canidentifytheneededinformationonthebladevibrations.Recenttheoreticaldevelopmentonthecouplingbetweenbladeandshafttorsionalvibrations,Al-Bedoor[12],indicatedtheexistenceofstrongdynamicinteractionbetweenblade-bendingandshaft-torsionalvibrations.Furtherexperimentalinvestigationswererecommended.TheLaservibrationpick-upformeasuringshafttorsionalvibrationsisalreadyinuseandit’ssuccesshasbeenproved[26,27,28].Thevitalproblemofrotatingbladevibrationsinturbo-machinery,theshortcomingsoftheavailablemethodsforbladevibrationmeasurements,therecenttheoreticalfindingsonthedynamicinteractionbetweenshaft-torsionalandblade-bendingvibrationsandthedevelopmentandverificationofthelaser-pickupformeasuringshafttorsionalvibrationshavemotivatedtheproposedresearch.Theproposedstudyaimstowardsutilisingtheshafttorsional/lateralvibrationtoextractinformationonthevibrationoftherotatingblades.Thisstudywillcontributetothebasictheoryoftheinteractionmechanismbetweenshaftandbladevibrationsinturbomachinery,whichwillbevaluabletotheoreticians,diagnosticsandmaintenanceengineers,andinthedevelopmentanddesignstagesofrotatingmachines.6.OBJECTIVESOFTHESTUDY Theproposedstudyaimsatdeveloping,experimentally,acorrelationbetweentherotatingbladeandthemainshaftvibrationsinturbo-machineryandjetengines.Themainobjectivesofstudyareasfollows;Developingatechniqueforidentifyingthehardtomeasurerotatingbladevibrationsusingthemeasurementsofthemainshafttorsionalvibrations.Tostudy,experimentally,thedynamicinteractionbetweenthebladeandshaftvibrations.Thestudywillcontributetothefundamentalsofrotordynamics.Toperformaparametricstudyondifferentcombinationofbladeandshaftpropertiesthatcanleadtosuchsystemsinstabilitiesandfailures.Tofurtherinvestigaterotordynamicvibrationproblems,suchasthebladeandstatorrubbingandtoprovideguidelinesforidentifyingsuchproblems.7.UTILIZATIONThestudyisexpectedtoprovideexcellentcontributiontothefundamentaltheoryofrotordynamics,inparticular,theshaft-bladedynamicinteractionthatisnotyetsatisfactorilyunderstood.Itoffersdevelopinganindirectmethodformeasuringbladevibration,whichisknowntobedifficultto