sacs dynamic response.pdf

3/10/2015 SACSDynamicResponse

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Copyright2012byBentleySystems,Inc.Version7.0Revision1

1.0INTRODUCTION

1.1OVERVIEW

TheDynamicResponseprogramisdesignedtocomputethedynamicresponsesofastructuresubjectedtodynamicexcitationduetobasemotionsuchasinanearthquake,ordynamicforcesduetoperiodicvibrationorimpactloads.Theprogramcananalyzebasedrivensystemswithinputdescribedeitherasaspectralinputorasatimehistoryinput,andforcedrivensystemswithinputdescribedbyasetofperiodforcesortimehistoryforces.

1.2PROGRAMFEATURES

DynamicResponseanalysisrequiresdynamicmodeshapeandmassfilesinadditiontoaDynamicResponseinputfile.

Somegeneralfeaturesandcapabilitiesoftheprogrammoduleare:

1.AbilitytouseafullstructuralmodelforuseinDynamicResponseanalysis.

2.Nonlinearfluiddampingeffectsincludedautomatically.

1.2.1Earthquake/BaseDrivenAnalysis

Bothspectralearthquakeandtimehistoryearthquakeanalysesaresupported.Someoftheseismicanalysiscapabilitiesfollow:

SpectralEarthquake

1.APIresponsespectraarebuiltintotheprogram.

2.Supportsuserdefinedresponsespectra.

3.Spectralmotioncanbedescribedasacceleration,velocity,ordisplacement.

4.Modalcombinationsusinglinear,SRSS,peakplusSRSS,orCQCmethods.

5.Abilitytouseadifferentresponsespectrumforeachdirection.

6.Combinesseismicresultswithstaticresultsautomatically.

7.Supportsuserdefinedpowerspectraldensities.

8.Abilitytogenerateresponsefunctionforanyjointdegreeoffreedom.

TimeHistoryEarthquake



1.Includesearthquaketimehistorylibraries.

2.Userdefinedinputtimehistories.

3.Linear,quadratic,orcubicinterpolationavailableforthetimehistoryinput.

4.Variabletimestepintegrationprocedure.

5.Automaticloadcaseselectionbasedonoverturningmoment,baseshear,etc.

6.Graphicalrepresentationofoutputvariables.

1.2.2ForceDrivenAnalysis

Forcetimehistory,PeriodicandEnginevibrationanalysesaresupported.Themaincapabilitiesandfeaturesforforcedrivenanalysisaredetailedbelow:

ForceTimeHistory

1.Linear,quadratic,orcubicinterpolationavailableforthetimehistoryinput.

2.Inputtimehistoriesmaybesavedtoafile.

3.Automaticloadcaseselectionbasedonoverturningmoment,baseshear,jointdisplacement,etc.


5.Timehistoryplotsincludingmodalresponses,overturningmoments,baseshear,etc.

6.Generationofequivalentstaticloads.

7.GenerationofincrementalloadsforCollapseanalysis

PeriodicVibration

1.Supportsinputforcesandmomentsappliedtoanypointatvariousfrequenciesandphaseangles.

2.Automaticloadcaseselectionbasedonmaximumjointdisplacementataspecificjointoratalljoints.

3.Fullplotcapabilitiesincludingmodalresponses,overturningmoments,baseshear,etc.

Engine/CompressorVibration

1.Supportsmechanicalunbalancedforcesandgastorquesinadditiontoreciprocatingloads.



2.Linearand/ornonlinearinterpolationofforcesbetweenrunningspeeds.

3.Usercanselectspecificjointstomonitorormonitoralljoints.

4.JointdisplacementscanbecomparedandplottedversusDline,SNAMEand/orMilitarySpecificationallowables.

5.Allowsuserdefinedphasingofforcesandmomentswithinaloadcase.

6.Canautomaticallycombinemaximumresponseofvariousloadcases.

7.Generatesplotsofinputdataversustimeforanyloadcase.

8.Calculatesperiodicforcesamplitudesandperiodsfromforceversustimeinput.

1.2.3SpectralWindAnalysis

Thewindspectralfatigueandextremewindanalysesaresupported.Someofthespectralwindanalysiscapabilitiesareasfollows:

ExtremeWind

1.Determinesdynamicamplificationfactorsautomatically.

2.Generatescommonsolutionfilecontaininginternalloads,stresses,reactionsanddisplacementsmultipliedbyitsowndynamicamplificationfactor.

3.IncludescrosscorrelationofmodalresponsesusingtheCompleteQuadraticCombination(CQC)modalcombinationtechnique.

4.Plotsgeneralizedforcespectrumandresponsespectrumforeachwindspeed.

5.UsesHarrisWindspectrum.

WindFatigue

1.UsesHarrisWindspectrum.

2.OptionallycreatesFatigueinputfileautomatically.

3.DistributeswindspeedutilizingaWeibulldistribution.

4.AssumesRayleighdistributionofRMSstresses.

5.Handlesmultiplewinddirectionsinsameanalysisexecution.

1.2.4IceForceAnalysis



IceVibration

Theicevibrationanalysiscapabilityincludesthefollowingfeatures:

1.Automaticallyincludesicestiffness.

2.Maximumandminimumpeakselection.

3.Automaticcyclecountforfatigueanalyses.

4.Createsfatigueinputdataautomatically.

5.Fullplotcapabilitiesincludingiceforces,modalresponses,overturningmoments,baseshear,etc.


1.2.5DynamicImpactAnalysis

Thedynamicimpactanalysiscapabilityincludesthefollowingfeatures:

1.Dynamicshipimpactanddroppedobjectanalysiscapabilities

2.Timehistoryplotsincludingmodalresponses

3.Generationofequivalentstaticloadsforstaticanalysis..

4.GenerationofincrementalloadsforCollapseanalysis

1.3PROGRAMSTRUCTURE

TheDynamicResponseprogramcanbeusedtosolvebasemotiontimehistoryorforcedrivensystems.

1.3.1BaseDrivenSystems

Thebasemotiontimehistorysolutionutilizesavariablestepintegrationprocedurethatdeterminesthelargesttimestepsizeallowedforeachsituationsuchthatresultsarewithinaspecifiedaccuracywhileanalysisexecutiontimeisoptimized.Thisprocedureallowstheprogramtousesmalltimestepsonlywhererequiredsuchasatpointsofrapidchanges.Theprocesscanalsoaccountforfluiddampingforsubmergedstructuresbyusinganequivalentfluiddampingasanalternativetocalculatingtheactualfluidforcesateachstepduringtheintegrationprocess.

1.3.2ForceDrivenSystems

Forforcedrivensystems,theDynamicResponseprogramcanpredicttheresponsesduetoasetofperiodicforcesandmomentsappliedtomultiplepointsonthe



structure.Theseforcescanbeatdifferentfrequenciesandphaseswithrespecttoeachother.Fortimehistoryforceinput,thesamevariablestepintegrationprocedureutilizedforbasedrivensystemsisusedtocalculatetheresponses.

ImpactAnalysis

TheDynamicResponsemodulecanpredicttheresponseofstructureresultingfromaimpactfromavesseloradroppedobject.Theprocesscanalsoaccountforfluiddampingforasubmergedportionofthestructurebyusingeitheranequivalentfluiddampingoralternativelytheprogramcancalculatetheactualfluidforcesateachstepduringtheintegrationprocess.

2.0ANALYSISPROCEDURE

TheDynamicResponseprogramisgenerallyusedtomodalresponsesintheformofvelocity,acceleration,displacementorstress.Thissectiondetailstheanalysisprocedureusedtodeterminethemodalresponsesforthefollowing:

A.BaseDrivenSystems

B.ForceDrivenSystems

C.SpectralWind

D.IceForce

E.DynamicImpactAnalysis

TheDynamicResponseprogramrequiresaDynpacmodeshapefile,DynpacmassfileandaDynamicResponseinputfile.Thefollowingdetailstheinputforthevarioustypesofdynamicanalyses.

2.1BASICANALYSISOPTIONS

Regardlessoftheanalysistype,basicanalysisoptionsmustbespecifiedintheDynamicResponseinputfile.

2.1.1AnalysisType

Theanalysistypeisenteredincolumns710ontheDROPTline.EnterSPEC,TIME,VIBR,WINDorENGVforspectralearthquake,timehistoryearthquake,forcedrivenperiodicortimehistory,spectralwindorenginevibrationanalysis,respectively.Enter'TCLP'togenerateincrementalloadsforforce/timehistorycollapseanalysis,enter'SHIP'fordynamicshipimpactanalysisorenter'DROP'fordynamicdroppedobjectanalysis.

2.1.2Damping

Dampingfactorscanhaveaprofoundeffectonanalysisresults.Theprogramhastheabilitytoconsiderbothstructuralandfluiddamping.

StructuralDamping

StructuraldampinginputisrequiredforanyresponseanalysisandisinputusingtheSDAMPline.Forsinglepassanalyses,thestructuraldampingvalueinputonthe



SDAMPlineshouldincludeallsourcesofdampingincludingfluiddampingifapplicable.

Note:FluiddampingmayoptionallybespecifiedormaybecalculatedautomaticallyusingtheFDAMPline.Whenfluiddampingiseitherspecifiedorcalculatedbytheprogram,thedampingvaluesontheSDAMPlineshouldnotincludeanydampingduetothefluid.

Ifallmodeshavethesamedamping,theoveralldampingasapercentofcriticalisinputincolumns1115ontheSDAMPlineandcolumns2170shouldbeleftblank.Thefollowingshowstotalcriticaldampingof3.0%forallmodes:

Ifthedampingvalueisdifferentforvariousmodes,thedampingvalueforeachmodemustbespecifiedintheappropriatecolumns.Dampingvaluesmustbespecifiedforeachmodeandmustbeexpressedasanonzeropositivenumber.Thesamplebelowshowsvariousdampingvaluesforthe15modestobeincludedintheanalysis.

FluidDamping

Fluiddampingmaybeoptionallyconsideredduringmostdynamicresponseanalysis.Theprogramhastheabilitytocalculatefluidmodaldampingautomaticallyortousedampingvaluesinputbytheuser.FluiddampingoptionsarespecifiedontheFDAMPlinefollowingtheSDAMPline.

CalculatingFluidDampingAutomatically

Whenfluiddampingiscalculatedbytheprogram,thevaluesarebasedonthenonlinearforcesonthestructure.Forspectralanalysis,anequivalentdampingratioisdeterminedbasedonaparticularamplitude.

EnterPCincolumns78iftheprogramistocalculatefluiddampingautomatically.Ifnonlineardampingistobeused,enterNLincolumns910.Fortimehistoryanalyses,entertheamplitudeincolumns1620ifaspecificamplitudeistobeusedtocalculatefluiddamping.

SpecifyingFluidDampingDirectly



Fluiddampingvaluesmaybespecifieddirectlybytheuser.Ifallmodeshavethesamefluiddamping,theoveralldampingasapercentofcriticalisinputincolumns1115ontheFDAMPlineandcolumns2170shouldbeleftblank.Thefollowingshowsfluiddampingof2.0%forallmodes:

Ifthedampingvalueisdifferentforvariousmodes,thedampingvalueforeachmodemustbespecifiedintheappropriatecolumns.Dampingvaluesmustbespecifiedforeachmodeandmustbeexpressedasanonzeropositivenumber.

Note:Forsinglepassanalysis,fluiddampingmustbeincludedinthevaluespecifiedforstructuraldampingontheSDAMPline.

2.1.3ModeSelection

Bydefault,theresponseofallmodesisconsideredinthedynamicresponseanalysis.Iftheresponseofsomemodesistobeignored,thenumberofmodestoconsidershouldbestipulatedincolumns1114ontheDROPTline.Whenthenumberofmodesnisspecified,theprogramassumesthatthefirstnmodesaretobeconsideredunlessmodenumbersaredesignatedusingtheMODSELinputline.Forexample,thefollowingdesignatesthatmodes110andmodes1620aretobeconsideredintheanalysis.

Note:ThenumberofmodesspecifiedontheMODSELlinemustbeequaltothenumberofmodesdesignatedontheDROPTline.

2.1.4VerticalCoordinate

Thepositiveverticalcoordinateaxis(X,+X,Y,+Y,Zor+Z)isenteredincolumns1718ontheDROPTline.

2.2BASEDRIVENANALYSIS

TheDynamicResponseprogramcanbeusedtodeterminestresses,jointvelocities,jointaccelerationsandjointdisplacementsforbothspectralandtimehistory



earthquake.

2.2.1SpectralEarthquake

TheDynamicResponseprogramcanbeusedtodetermineresponseduetoaresponsespectrum.Seismicanalysistype,seismicloaddataandanalysisoutputoptionsaredesignatedintheDynamicResponseinputfileinadditiontothebasicanalysisoptions.

AnalysisType

EnterSPECincolumns710ontheDROPTlinetodesignateaspectralearthquakeanalysis.

SeismicLoadData

Forspectralearthquakeanalysis,theseismicloaddataisinputaftertheLOADheaderlineintheformofaresponsespectrumorapowerspectraldensityfunction.TheprogramcontainsanautomatedAPIspectralanalysisfacilitydesignatedbytheSPLAPIlinealongwithageneralresponsespectralanalysisfacilitydesignatedbytheSPLOADline.

Note:EachseismicinputloadrequireseitheraSPLAPIoraSPLOADline.

AutomatedAPISpectralAnalysis

TheautomatedfacilitycontainsAPISoilTypeA,BandCresponsespectrainadditiontosupportinguserdefinednormalizedresponsespectra.EachseismicloadtobedefinedbyoneoftheAPIspectraisinputusingaSPLAPIlineasfollows:

EntertheresponsefactororGfactorwhichdefinestheratioofeffectivehorizontalgroundaccelerationtogravitationalaccelerationincolumns1115.ThesoiltypeortheIDoftheuserdefinedresponsespectrumandtheDirectionalityfactortobeappliedtotheGfactormustbespecifiedfortheX,YandZdirectionsincolumns1636.Themethodusedtocombinemodalresultsisdesignatedincolumns3841.EnterSRSS,PEAK,PRMSorCQCforsquarerootofthesumofthesquares,linearadditionofabsolutevalues,peakplusSRSSorcompletequadraticcombination,respectively.

Note:StructuraldampingonlyisassumedwhenusingtheautomatedAPIspectralanalysis.Also,theIDoftheuserdefinednormalizedresponsespectrummaybeinputinplaceofthesoiltype.

GeneralSpectralResponseAnalysis

ThegeneralspectralanalysiscapabilitiesallowsseismicloadingtobedefinedusingAPIoruserdefinedinputspectrum.APIspectramaybereferencedorresponsespectrumorpowerspectraldensityfunctiondatamaybespecified.RegardlessofwhetherAPIspectraoruserdefineddataisused,generalloadoptionsandloaddatamustbespecifiedontheSPLOADlineasfollows:

SpecifythedampingtypeSDOstructuraldampingonly,FDSequivalentfluiddampingatspecifiedamplitudeorFDAequivalentfluiddampingatactualamplitudeincolumns2123.ForFDSdamping,enterthedampingamplitudeincolumns3944ifdifferentfromthevaluespecifiedontheFDAMPline.

Note:OptionsFDAandFDSrequirethatfluiddampinginputbespecifiedusingtheFDAMPline.



Themethodusedtocombinemodalresultsisdesignatedincolumns2528.EnterSRSS,PEAK,PRMSorCQCforsquarerootofthesumofthesquares,linearadditionofabsolutevalues,peakplusSRSSorcompletequadraticcombination,respectively.

EntertheresponsefactororGfactorwhichdefinestheratioofeffectivehorizontalgroundaccelerationtogravitationalaccelerationincolumns4550.ThedirectionalityfactortobeappliedtotheGfactormustbespecifiedfortheX,YandZdirectionsincolumns5156,5762and6368,respectively.

APISpectrum

Enterthespectrumsource,eitherAPI,APIA,APIB,orAPICforAPIspectraincolumns912ontheSPLOADline.Leavecolumns1518blank.

UserDefinedSpectra

Userdefineddatamaybespecifiedintheformofanormalizedresponsespectrum,ageneralresponsespectrumorapowerspectraldensityfunction.

NormalizedresponsespectraareusedinconjunctionwiththeSPLAPIlinebyspecifyingtheIDofthespectruminsteadofasoiltypeincolumns22,29or36.

NormalizeduserdefinedresponsespectrumdatamaybeusedtodefineadditionalsoiltypestobeusedinconjunctionwiththeAPIspectralearthquakeoptions.ThespectrumdataisspecifiedusingRSPU1andRSPU2linesimmediatelyfollowingtheSPLAPIline.ThefirstRSPU1linerequiresthenumberofdampingvalues(maximumof3)incolumn10alongwiththeIDofthespectrumincolumn8.ThespectrumdataisenteredontheRSPU2lineandincludesthedampingratioasapercentofcriticaldampingincolumns914,thentheperiodandnormalizedspectrumvalueofeachpointofthespectrumincolumns2180.

Note:UptofifteenspectrumpointsmaybedefinedbyrepeatingtheRSPU2linewiththesamedampingratiospecifiedoneachline.

ThefollowingdescribesanuserdefinedresponsespectrumtobeusedassoiltypeFintheXdirectionwith5percentcriticaldampingandisdefinedby5setsofperiodsandvalues.

ThegeneralresponsespectrumandthepowerspectraldensityfunctionareusedwiththeSPLOADlinebyenteringthespectrumsourceincolumns912ontheSPLOADlineasLINEifthespectrumdataisdefinedonsubsequentinputlines,FILEifthespectrumisdefinedinaexternalfileorPREVifthespectrumistobeusedfromthepreviousseismicloadcase.Enterthespectrumtype,RSPforresponsespectrumorPSDforpowerspectraldensityincolumns1517ontheSPLOADline.AccelerationA,velocityVanddisplacementDspectraaresupported.Specifythespectrumformbyenteringtheappropriateletterincolumn18iftheuserdefined


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dataisintheformofaresponsespectrum.

UserdefinedresponsespectrumdataisspecifiedusingRSPSPClinesimmediatelyfollowingtheSPLOADline.ThefirstRSPSPClinerequiresthenumberofdampingvaluesincolumns710.Enterthenumberofpointsdefinedonthecurveincolumns710onthesecondRSPSPClinealongwiththecriticaldampingforthecurveincolumns1116.Thefirsttwopointsonthecurve,definedbyaperiodandaresponsevalueareenteredincolumns2160.Additionalpointsonthecurvearedefinedinpairsincolumns2160onsubsequentRSPSPClines.

Forexample,thefollowingdescribesanuserdefinedresponsespectrumdefinedby5setsofperiodsandaccelerations(accelerationform)with5percentcriticaldamping.

UserdefinedpowerspectraldensitydataisspecifiedusingPSDSPClinesimmediatelyfollowingtheSPLOADline.ThefirstPSDSPClinerequiresthenumberoffrequencyvaluesincolumns710.Thefirsttwopointsonthecurve,definedbyafrequencyandaspectraldensityvalueareenteredincolumns2160.Additionalpointsonthecurvearedefinedinpairsincolumns2160onsubsequentPSDSPClines.

Forexample,thefollowingdescribesanuserdefinedpowerspectraldensityfunctiondefinedby5setsoffrequenciesandspectraldensityvalues.

OutputOptions

Bydefault,seismicloadcasesarecreatedwhenperformingaspectralearthquakeanalysis.Theprogramalsohastheabilitytooutputloadcombinationsconsistingof



seismicandstaticresults,equivalentstaticloadsfornonlinearanalysis,responsefunctionsandjointdataincludingdisplacement,velocityandacceleration.

Static+SeismicCombinations

TheDynamicResponsehastheabilitytooptionallycombineseismicresultswithstaticresultsaspartoftheearthquakeanalysis.Whenusingthisfeature,theprogramcreatesfourseismic+staticloadcombinations,twoforelementcheckandtwoforjointcancheck,foreachseismicloadcaseasfollows:

Note:Thisfeaturerequiresthatthestaticsolutionfileexistpriortoexecutionoftheseismicanalysis.Italsoresquiresthatallseismicloadcasesarefullseismicloadcasescontainingtheresponsesforalldirections(i.e.X,YandZresponses).Whenusingseismicloadcasescontainingonlypartoftheseismicresponse,theseloadcasesmustbecombined(usingSRSS)bytheuserpriortomanuallycombiningwithstaticsolutions.

TheseismicandstaticcombinationinformationisinputusingtheSTCMBline.Enterthefactortobeappliedtotheseismicloadswhencombinedwiththestaticloadsforthepurposeofmemberandplateelementcheckincolumns812.Thefactortobeappliedtoseismicloadswhencombinedwithstaticloadsforjointcheckisinputincolumns1317.Entereachofthestaticloadcasestobecombinedwiththeseismicloadcasesandtheloadfactortobeapplied.Sincespectralearthquakeresultsarevalidonlyatthejointsofthestructure,itisrecommendedthattheJOoptionisusedincolumns2728oftheOPTIONSlinewhengeneratingthestaticsolutionfile.

Forexample,105%ofloadcases8and9containedinthestaticsolutionfilearetobecombinedwiththeseismicsolution.Forelementcheckandjointcancheck,seismicstressesaretobefactoredby1.0and2.0,respectively.



Note:TheSTCMBlineshouldfollowtheSDAMP,FDAMPandMODSELlinesintheinputfile.

EquivalentStaticLoads

EquivalentstaticloadsusedtosimulateearthquakeloadsfornonlinearanalysismaybecreatedusingtheEQKLODline.TheloadcasecanbecreatedtorepresenteithertheactualbaseoractualoverturningmomentbydesignatingSorMincolumn8.

Bydefaultmodalresultsareaddedtogethersuchthatthecorrespondingloadrepresentseitherbaseshearoroverturningmoment.TheloadcasemayalsobegeneratedwiththesignreversedtosimulateloadreversalbyspecifyingRincolumn10.Toobtainoneloadcasecorrespondingtothestandardloadingandanadditionalloadingrepresentingthereversal,enterBincolumn10.Toobtainoneloadcasecorrespondingtoloadingin"all"directions,enterAincolumn10.Inthiscasethenumberofdirectionsmustbespecifiedincolumns1416,withadefaultvalueof20andamaximumof100.

Theloadcasescreatedmaybeappendedtoanexistingmodelorstructuraldatafile.Iftheexistingfilecontainsloadingtobeusedbythesubsequentnonlinearanalysis,theloadcasetoassigntothegeneratedloadsmaybeassignedbydesignatingthenumberofexistingloadcasestoskipincolumns1113.

TheprogramprintstheresponseintheX(0.0degree)andY(90.0degree)directions.WhenthestructureisrespondingprimarilyintheXdirection,theseresponsesdonotoccuratthesametime.Theequivalentstaticloadprocedureassumesthattheprimarystructureresponsemayoccurinanydirectionduringtheearthquakeevent(notonlyalongtheXorYaxes).Theresponseofthestructureisthereforecalculatedfor20directions(every18degrees).Foreachofthesetwentydirections,thebaseshearinthatdirectionandthemomentaboutthatdirectionaredetermined.Equivalentstaticloadsarethengeneratedforthehighestbaseshear.

Aseparateloadcasemaybeoutputforeachmodebyentering'M'incolumn17oftheEQKLODinputline.

TheseismicloadcasescreatedhavetheearthquakeEQSloadingplustheloadcasesspecifiedontheSTCMBlineincludedineachloadcasecreated.TheloadcasesontheSTCMBlinearefactoredbytheappropriateloadfactorindicatedontheSTCMBline.ThejointandmemberloadcasesfactorsontheSTCMBlineareignored.

ResponseFunctions

AfrequencyorperiodresponsefunctionsmaybegeneratedatspecificlocationsonthestructureusingtheRSFUNCline.UptosixfunctionsmaybegeneratedforeachRSFUNClinedesignated.Enterthejointname,thedegreeoffreedomandthedampingtobeusedincolumns716.Additionalfunctionsmaybegeneratedbyspecifyingthejoint,DOFanddampingincolumns1766.Thenumberofpointsusedtodefinethefunctionsisdesignatedincolumns6769whilethefunctiontypeisdesignatedby



P(period)orF(frequency)incolumn70.Plotsoptionsarespecifiedincolumns7377.

AsmanyRSFUNClinesasrequiredtodesignatethedesirednumberoffunctionsmaybeused.

JointResults

Jointresultssuchasvelocity,accelerationanddisplacementmaybereportedforaparticularseismicloadcasebyenteringV,AorDincolumns2931onthecorrespondingSPLOADline.Resultsmayalsobereportedforallseismicloadcasesbyspecifyingtheprintselectionsincolumns2527ontheDROPTline.

LowLevelEarthquakeAnalysis

LowlevelearthquakeanalysisbasedonAPIWSDorAPILRFDmaybeaccomplishedusingthemethodsfromthepreviousparagraphs.Tospecifylowlevelearthquakeanalysis,theAPIcoderequiresdescriptionofarare,intenseearthquakeforanalysis.Thefollowingsamplespecifiesconditionsforarare,intenseearthquakeandtheproperloadcombinationsforuseinlowseismicactivityzonesperAPI.

TheSTCMBlinespecifiesanelementloadcasefactorof1.0andapunchingshearfactorof.0001.Thiseffectivelyeliminatesseismicloadsfromloadcases3and4generatedbytheSPLAPIline.Loadcase3,whichiseffectivelyadeadloadcase,willbeusedsubsequentlyinjointcanlowlevelearthquakeanalysis.SeeJointCanmanualforimplementationoflowlevelearthquakeanalysisinjointstrengthcheck.

CombiningwithStaticResults

Theprogramcreatesacommonsolutionfilecontainingendforces,stresses,reactionsanddisplacementsforeachseismicloadsetspecifiedintheDynamicResponseinputfile.BecausetheseresultsareobtainedbycombiningmodalresultsusingRMStechniques,endforces,stresses,etc.havenosignassociatedandaretakenasall



positivevalues.Therefore,whenmanuallycombiningspectralearthquakeresultswithstaticresults,thePRSTandPRSCcombineoptionsmustbeused.

2.2.2TimeHistoryEarthquake

TheDynamicResponseprogramcanbeusedtodetermineresponseduetoabasedriventimehistory.Uptothreeseparatetimehistoriesmaybeusedforanyanalysis.Analysistype,seismicloaddataandanalysisoutputoptionsaredesignatedintheDynamicResponseinputfileinadditiontothebasicanalysisoptions.

AnalysisType

EnterTIMEincolumns710ontheDROPTlinetodesignateatimehistoryearthquakeanalysis.

LoadOptions

Fortimehistoryearthquakeanalysis,inputloadingandloadoptionsareinputaftertheLOADheaderlineusingtheTHLOAD,THFACT,TIMEandTHBEGINinputlines.

Note:Eachtimehistoryloadisdefinedbyusingaseparatesetoftheselines.

DampingMethod

GeneraltimehistoryoptionsaredesignatedontheTHLOADlineimmediatelyfollowingtheLOADheader.SpecifythedampingtypeSDOstructuraldampingonly,LFDlinearizedfluiddampingorNFDfornonlinearfluiddampingincolumns1820.

Note:Fornonlinearfluiddamping,thefluidforcesarecalculatedateverytimestepduringtheintegration.ThisoptionrequirestheprogramcalculatedfluiddampingoptionPContheFDAMPline.

Forlinearizedfluiddamping,thedampingamplitudeusedtocalculatetheequivalentlinearfluiddampingmaybeoverriddenbyspecifyingavalueincolumns2128.

InterpolationScheme

Themethodusedtointerpolatebetweentimehistoryinputvaluesisdesignatedincolumns2930.EnterLN,QDorCUforlinear,quadraticorcubicinterpolation,respectively.

DirectionalityFactors

ThedirectionalityfactortobeappliedtothetimehistoryvalueisspecifiedfortheX,YandZdirectionsincolumns1115,1620and2125oftheTHFACTline,respectively.Ifmorethanonetimehistoryistobeused,thedirectionalityfactorsforeachtimehistorymustbespecifiedincolumns2655.

IntegrationParameters

IntegrationparametersarestipulatedontheTIMEline.Enterthestartforthebeginningofthetimehistoryintegrationincolumns1120.Iftheanalysisistoterminatebeforetheendofthetimehistoryinput,entertheendtimeincolumns2130.Theoutputtimeinterval,minimumintegrationstepandthetolerancefactoraredesignatedincolumns3140,4150and5160,respectively.



Forexample,thefollowingdescribesantimehistoryfunctionspecifiedintheinputfile.StructuraldampingonlyisusedinconjunctionwithlinearinterpolationasdesignatedontheTHLOADline.Onetimehistoryfunctionisusedwithdirectionalityfactorsof1.0,1.0and0.5appliedtoitfortheX,YandZdirections,respectively.Thestarttimeis0secondsandendtime25seconds.Outputisrequestedatevery0.25seconds.

TimeHistoryInput

TimehistorydatamaybespecifiedintheDynamicresponsefileormaybereadfromanexternaldatafile.Thesourceofthetimehistorydataisdesignatedincolumns912ontheTHLOADline.EnterLINEifthetimehistorydataisdefinedonsubsequentinputlines,FILEifthedataisdefinedinaexternalfileorPREVifthetimehistorydataistobeusedfromthepreviousseismicloadcase.

InputParameters

SpecifyingdataintheinputfilerequiresthatoverallparametersbespecifiedontheTHBEGINline.Upto3separatetimehistoriesmaybedefinedforaparticularinputload.Enterthenumberoftimehistoriestobedefinedinthefileincolumns810andthenameidentifyingthetimehistoryincolumns2225.Thetype,eitheracceleration,velocity,displacementorgravityaccelerationisdesignatedbyA,V,DorGincolumn30,respectively.

TimeHistoryLoadData

Thetimehistorydatamaybeenteredinstandardformat,compressedformatorviaanexternalinputfile.

StandardFormat

SpecifySTDincolumns1420ontheTHBEGINlineforstandardinputformat.

TimehistoryloaddataisspecifiedusingaTHDATAlineforeachtimepoint.Foranytimepoint,enterthetimeincolumns1120andthevalueincolumns2130.Ifmorethanonetimehistoryistobedefined,enterthevalueforthesecondfunctioncorrespondingtothistimeincolumn3140.Thevalueforthethirdfunctionisinputincolumns4150.Thefollowingillustratesoneaccelerationtimehistoryinputusingstandardformat.



Note:Thefirsttimepointofthetimehistoryfunctionisassumedtobezero.Thefirsttimepointenteredbytheusermustbegreaterthanzero.ThetimehistoryisterminatedbyusingaTHDATAlinewithallfieldleftblank.

CompressedFormat

ThetimehistorydatamaybeenteredincompressedformatbyspecifyingCMPincolumns1420ontheTHBEGINline.

TimehistoryloaddataisspecifiedusingaTHCOMPlineforeachtimepoint.Compresseddataisassumedtobespecifiedwiththeconstanttimeintervalspecifiedincolumns1420ontheTHBEGINline.Enterthetimehistoryvalueincolumns1170.TheTHCOMPlinewithENDdesignatedincolumns810signifiestheendoftheinputdata.

Thefollowingillustratesoneaccelerationtimehistoryinputusingcompressedformat.Theconstanttimeintervalis0.25secondsasdesignatedontheTHBEGINline.



ExternalFileInput

Whenspecifyingtimehistoryloaddatafortimehistoryearthquake,datawhichwouldnormallybespecifiedusingTHDATAlinesisinputinanexternalinputfilewithoutdatalabels.Theexternalfilebeginswithasinglerecord.ThisrecordbeginswithafourcharacternameasspecifiedontheTHLOADdatarecord.Thenextfourcolumns,columns58,specifythenumberoftimehistoryfunctionsasspecifiedincolumns810oftheTHBEGINdatarecord.Thetype,eitheracceleration,velocity,displacementorgravityaccelerationisdesignatedbyA,V,DorGincolumn9,respectively.Theinputunitsinches,feet,centimeters,millimetersandmetersareinputbyspecifying'IN','FT','CM','MM'and'ME'incolumns1213respectively.

ThefollowingrecordsaretheequivalentofTHDATArecordsinstandardformat,butareinputwithspecificfieldwidthsandnodatalabels.Columns112specifythetimepointthisisequivalenttocolumns1120oftheTHDATArecord.Columns1324,2536and3748consistofthetimehistoryvaluesforthefirst,secondandthirdfunction,respectively.Thenumberoftimehistoryfunctionvaluesspecifiedmustcorrespondtothevalueincolumns58ofthefirstrecord.Subsequentrecordsspecifyothertimehistorypoints.Alltimehistorypointsspecifiedmusthavetimepointsgreaterthanzero.Thefinalrecordhasatimepointof0.0.

Thefollowingisanexampleofexternalfileinput.Inorderforthisfiletobeused,thedynamicresponseinputfilemusthaveaTHLOADrecordwithtimehistoryinputsourcefield(columns912)ofMXCT.Theinputspecifiesthreetimehistoryfunctionvaluesarespecifiedintheforthcomingrecords.Theinputtimevaluesof0.00,0.02,0.04,0.06,0.08and0.10aredatainthefirsttwelvecolumnsthethreetimehistoryfunctionvaluesarespecifiedincolumns1324,2536and3748.Typicaldatainputwouldconsistofmanymorerecords.Thelastdatarecordhasatimepointof0.0.



OutputOptions

Thetimehistoryearthquakeanalysiscreatesloadcases,printsandplotsmodalresponses,baseshearandoverturningmomentinadditiontojointaccelerations,velocitiesanddisplacements.Analysisoutputoptionsaredesignatedintheoutputoptionsfieldsincolumns3359ontheTHLOADline.

LoadCaseCreation

TheDynamicResponseprogramhastheabilitytocreatealoadcasecorrespondingtothetimepointhavingmaximumoverturningmomentand/ormaximumbaseshearbyspecifyingMXMorMXSintheoutputoptionsfieldsontheTHLOADline,respectively.EnterALLifloadcasesaretobecreatedatforalltimepoints.

ModalResponseData

Modalresponsesversustimemaybeprintedand/orplottedbyspecifyingPRTandPLT,respectively,intheoutputoptionsfieldsontheTHLOADline.

BaseShearandOverturningMomentPlots

BaseshearandoverturningmomentplotsmaybegeneratedbyenteringPLMandPLSinoneoftheoutputoptionfieldslocatedontheTHLOADline.

JointResults

Jointresultsincludingacceleration,velocityanddisplacementmaybeplottedandlistedforuptosixteenjoints.JointplotoptionsarespecifiedintheoutputoptionsfieldsontheTHLOADline.

Jointaccelerationoptionsinclude:

JMAPrintsmaximumandminimumvaluesforjointaccelerationforeachdirection.



JPASameasJMAplusplotsaccelerationtimehistory

JTASameasJPAplusprintsaccelerationtimehistorydata

Note:Jointaccelerationoptionsaremutuallyexclusive.Onlyoneoftheoptionsmaybeselected.

Jointvelocityoptionsinclude:

JMVPrintsmaximumandminimumvaluesforjointvelocityforeachdirection.

JPVSameasJMVplusplotsvelocitytimehistory

JTVSameasJPVplusprintsvelocitytimehistorydata

Note:Jointvelocityoptionsaremutuallyexclusive.Onlyoneoftheoptionsmaybeselected.

Jointdisplacementoptionsinclude:

JMDPrintsmaximumandminimumvaluesforjointdisplacementforeachdirection.

JPDSameasJMDplusplotsdisplacementtimehistory

JTDSameasJPDplusprintsdisplacementtimehistorydata

Note:Jointdisplacementoptionsaremutuallyexclusive.Onlyoneoftheoptionsmaybeselected.

Anynumberofjointsmaybedesignatedforplotsandreports.JointstobeoutputarespecifiedusingJTNUMlinesimmediatelyfollowingtheTHLOADline.

Thefollowinginputillustratessomeoftheoutputoptions.Twoloadcases,onecorrespondingtothetimeofmaximumbaseshearandonecorrespondingtothetimeofmaximumoverturningmoment,arecreated.Baseandoverturningmomenttimehistoriesaretobeplottedinadditiontojointaccelerationanddisplacementplotsforjoints601,603,605and607.

2.3FORCEDRIVENANALYSIS



TheDynamicResponseprogramcanbeusedtodeterminestresses,jointvelocities,jointaccelerationsandjointdisplacementsforstructuressubjectedtoperiodicforces,forcetimehistoryorengine/compressorvibration.

Forperiodic,timehistoryorengine/compressorvibrationanalysis,theanalysistype,loaddataandanalysisoutputoptionsaredesignatedintheDynamicReponseinputfileinadditiontothebasicanalysisoptions.

2.3.1ForceTimeHistory

AnalysisType

TheanalysislabelVIBRmustbeenteredincolumns710ontheDROPTlineforanyforcedresponseanalysis.Forforcetimehistoryanalysis,enterTHISincolumns710ontheFVIBline.

LoadOptions

LoadoptionsandinputloadingisspecifiedfollowingtheLOADheaderlineusingtheFVIB,TIME,THFORCEandLOADlines.BasicloadoptionsaredesignatedontheFVIBlinewhileintegrationparametersarespecifiedontheTIMEline.

Note:EachtimehistoryloadrequiresaseparatesetofFVIB,TIME,THFORCEandLOADlines.

DampingMethod

SpecifythedampingtypeSDOstructuraldampingonly,LFDlinearizedfluiddampingorNFDfornonlinearfluiddampingincolumns1719oftheFVIBline.



InterpolationScheme

Themethodusedtointerpolatebetweeninputvaluesisdesignatedincolumns2839ontheFVIBline.EnterLNforlinear,QDforquadraticorCUforcubic.

Note:Ingeneral,linearinterpolationisapplicableforstep,ramporspikefunctions.Thequadraticandcubicinterpolationmethodssmoothsouttheinputfunction.

Forexample,thefollowingdescribesantimehistoryfunctionspecifiedintheinputfile.StructuraldampingonlyisusedinconjunctionwithlinearinterpolationoftheforcetimehistoryinputasdesignatedontheFVIBline.





Forexample,thefollowingdescribesantimehistoryfunctionspecifiedintheinputfile.StructuraldampingonlyisusedinconjunctionwithlinearinterpolationasdesignatedontheFVIBline.Thestarttimeis0secondsandendtime25seconds.Outputisrequestedatevery0.25seconds.

TimeHistoryInput

TimehistoryinputdatamaybespecifiedintheDynamicresponsefileormaybereadfromanexternaldatafile.Thesourceofthetimehistorydataisdesignatedincolumns912ontheFVIBline.EnterLINEifthedataisdefinedonsubsequentinputlines,FILEifthetimehistoryisdefinedinaexternalfileorPREVifthedataistobeusedfromthepreviousloadcase.

InputParameters

Whenspecifyingforcetimehistorydataintheinputfile,timehistoryinputparametersmustbespecifiedontheTHFORCEline.Enterthetotalnumberofjointsthatforceisappliedincolumns810.Timehistorydatamaybeinputusingauniformtimeintervalbetweenpointsormaybespecifiedforvarioustimepointsspacednonuniformly.Theinputformat,eitheruniformornonuniformmustbedesignatedbyUNIorNONincolumns1113respectively.Foruniforminput,specifythetimeintervalincolumns1420.Thetimehistorynameisinputincolumns2225.ThefollowingillustratestheinputrequiredforthenonuniformtimehistoryinputnamedTESTappliedatonejoint.



TimeHistoryData

ThetimehistoryinputdataisspecifiedusingLOADlineslocatedaftertheTHFORCEline.Enterthejointtowhichtheloadisappliedincolumns811.Thetimethattheloadistobeappliedisenteredincolumns1216.IfseveraltimesarespecifiedinconsecutiveLOADlines,thetimesmustbeinascendingorder.Theforcesandmomentsactingonthejointatthespecifiedtimearedesignatedincolumns1759.

Forexample,aloadof10.0isappliedintheglobalXdirectiontojoint107attime1.0seconds.Theloadremainsconstantfor0.25secondsafterwhichitisremoved.

Note:Noticethatthethirdtimepointisdefinedat1.001secondsinsteadof1.00secondssothattheforceisappliedoverasmalltimeperiodratherthanappliedinstantaneously.

ScalingLoadData



Loaddatamaybefactoredbyspecifyingaloadfactorincolumns5965ontheFVIBline.

LoadCaseTimeHistoryData

TimehistoryinputdatamayalsobespecifiedusingLOADClines.TheselinesarelocatedaftertheTHFORCEline.Inthiscase,ratherthanspecifyingjointsatwhichtheloadappliesandsupplyingatimehistory,theloadsfromtheSACSIVloadcasespecifiedincolumns811ontheLOADClinewillbeappliedatthetimespecifiedincolumns1216.IfseveraltimesarespecifiedinconsecutiveLOADClines,thetimesmustbeinascendingorder.Thescalingfactortobeappliedtotheloadsisspecifiedincolumns1723.Thismethodisveryusefulforapplyingsimilartimevaryingloadstomanypositions,asinblastloading.Noticealsothatthisloadingisnotlimitedtojointloadsonlydistributedandpressureloadsmaybeappliedinthismanneraswell.

Forexample,loadcaseB01isappliedwithascalingfactorof0.0attime1.0seconds,afactorof1.0attime1.001seconds,afactorof1.0attime1.25seconds,afactorof0.0attime1.251secondsandafactorof0.0attime10.0seconds.IfloadcaseB01specifiedaloadatjoint107of10.0intheglobalXdirection,thenthisexamplewouldresultinthesameloadingatjoint107asthepreviousLOADexample.

TimeHistoryCollapseAnalysis

IncrementalloadsforforcetimehistoryCollapseanalysiscanbegeneratedbyspecifyingTCLPincolumns710ontheDROPTinputline.Also,incrementalloadsfromadynamicshipimpactCollapseanalysiscanbegeneratedbyspecifying'SHIP'incolumns710ontheDROPTlinetogetherwith'CLP'incolumns3335ontheTHLOADinputline.Alternatively,equivalentstaticloadscanbegeneratedbyspecifying'ESL'incolumns3335ontheTHLOADinputline.

TheexamplebelowreferstoadynamicshipimpactanalysiswithincrementalloadsbeinggeneratedforasubsequentCollapseanalysis.Theweight,speedanddirectionofimpactisdefinedontheSHIPinputlinetogetherwithimpactedjointname.



OutputOptions

Theforcetimehistoryanalysiscreatesloadcases,printsandplotsmodalresponses,baseshearandoverturningmomentinadditiontojointaccelerations,velocitiesanddisplacements.Analysisoutputoptionsaredesignatedintheoutputoptionsfieldsincolumns3258ontheFVIBline.

LoadCaseCreation

Loadcasescorrespondingtoeachtimepointorthecriticaltimepointsmaybegeneratedbytheforcedresponseanalysis.Loadcasescorrespondingtothetimepointhavingmaximumoverturningmoment,maximumbaseshearorbothbyspecifyingMXM,MXSorMMSintheoutputoptionsfieldsontheFVIBline,respectively,maybecreated.EnterALLtohavealoadcasecreatedateachtimepointoftheanalysis.

Note:Loadoptionsaremutuallyexclusive.Onlyoneoftheoptionsmaybedesignated.

ModalResponseData

Modalresponsesversustimemaybeprintedand/orplottedbyspecifyingPRTandPLT,respectively,intheoutputoptionsfieldsontheFVIBline.EnterPPTtohavemodalresponsesprintedandplotted.

Note:Modalresponseoptionsaremutuallyexclusive.Onlyoneoftheoptionsmaybedesignated.


BaseshearandoverturningmomentplotsmaybegeneratedbyenteringPLMandPLS,respectively,inoneoftheoutputoptionfieldslocatedontheFVIBline.



JointResults

Jointresultsincludingacceleration,velocityanddisplacementmaybeplottedandlistedforuptosixteenjoints.JointplotoptionsarespecifiedintheoutputoptionsfieldsontheFVIBline.
















Uptosixteenjointsmaybedesignatedforplotsandreports.JointstobeoutputarespecifiedusingtheJTNUMlineimmediatelyfollowingtheTHLOADline.

Thefollowinginputillustratessomeoftheoutputoptions.Twoloadcases,onecorrespondingtothetimeofmaximumbaseshearandonecorrespondingtothetimeofmaximumoverturningmoment,arecreated.Baseandoverturningmomenttimehistoriesaretobeplottedinadditiontojointaccelerationanddisplacementplotsforjoints601,603,605and607.



2.3.2PeriodicVibration

AnalysisType

TheanalysislabelVIBRmustbeenteredincolumns710ontheDROPTlineforanyforcedresponseanalysis.Forperiodicvibrationanalysis,enterPERIincolumns710ontheFVIBline.

LoadOptions

PeriodicloadingandoptionsforthatloadingisdefinedusingtheFVIBandLOADinputlinesspecifiedaftertheLOADheaderline.GeneralloadoptionsarespecifiedontheFVIBline.

Note:EachperiodicloadingdefinedrequiresaseparatesetofFVIBandLOADinputlines.

DampingMethod

SpecifythedampingtypeSDOstructuraldampingonly,LFDlinearizedfluiddampingorNFDfornonlinearfluiddampingincolumns1719ontheFVIBline.



TimeParameters

Forperiodicvibrationthetimespanthatthevibrationistobemonitoredisinputincolumns7277ontheFVIBline.Ingeneralthistimespanistheshortesttimethatthevibrationisrepeatable.Thenumberoftimepointsthatthetimespanistobedividedisspecifiedincolumns7880.

Note:Thenumberoftimepointsshouldbesufficienttopickupthehighestfrequencyofinterest.

Forexample,thefollowingdescribesanperiodicfunctionspecifiedintheinputfile.Structuraldampingonlyisusedinconjunctionwithquadraticinterpolationoftheperiodicinput.Theanalysistimespanis1.0secondandtheanalysisistobebrokenupinto50timepoints.



PeriodicInput

PeriodicloaddatamustbespecifiedintheDynamicResponseinputfileusingLOADlineslocatedaftertheFVIBline.Inputloaddatamaybescaledautomaticallybyenteringaloadscalingfactor.

PeriodicLoadData

Enterthejointtowhichtheloadisappliedincolumns811.Theforcesandmomentsactingonthejointaredesignatedincolumns1759.

Entertheperiodthatthesetofforcesisactingincolumns6974alongwiththephaseangleincolumns7580.

Note:ForcesareappliedasF*cos(2pT/(T+a))whereTistheperiodandaisthephaseangle.

Forexample,aperiodicforceof10.0isappliedintheglobalXdirectiontojoint107.Theperiodis0.20secondsandthephaseangleis90degrees.

ScalingLoadData

Loaddatamaybefactoredbyspecifyingaloadfactorincolumns5965ontheFVIBline.

OutputOptions

Theperiodicvibrationanalysiscreatesloadcases,printsandplotsmodalresponses,baseshearandoverturningmomentinadditiontodeterminingmaximumabsolutedisplacements.Analysisoutputoptionsaredesignatedintheoutputoptionsfieldsincolumns3258ontheFVIBline.

LoadCaseCreation



Loadcasescorrespondingtoeachtimepointorthecriticaltimepointsmaybegeneratedbytheperiodicvibrationanalysis.Loadcasescorrespondingtothetimepointhavingmaximumoverturningmoment,maximumbaseshearorbothbyspecifyingMXM,MXSorMMSintheoutputoptionsfieldsontheFVIBline,respectively,maybecreated.EnterALLtohavealoadcasecreatedateachtimepointoftheanalysis.

Note:Theaboveloadoptionsaremutuallyexclusive.Onlyoneoftheoptionsmaybedesignated.

Theprogramalsohastheabilitytocreatealoadcasecorrespondingtothetimeofmaximumdisplacementorrotationforaparticularjoint.Enterthejointnameincolumns6669andthedegreeoffreedomtomonitorincolumns7071ontheFVIBline.

Note:Whencreatingaloadcaseforamaximumjointdisplacementorrotation,nootherloadcasesarecreated.Therefore,theMXM,MXSandMMSmaynotbeusedwhenusingthisfeature.

ModalResponseData




BaseshearandoverturningmomentplotsmaybegeneratedbyenteringPLMandPLSinoneoftheoutputoptionfieldslocatedontheFVIBline.

JointDisplacements

Jointmaximumdisplacementresultsmaybeprintedusingoneofthefollowingoptions:

MXDprintsmax.X,YandZdisplacementofeachjointinthestructure

SMDselectsmax.displacementforallperiodicloadcasesforeachjoint.

DSMprintsmax.absolutesumofX,YandZdisplacementforeachperiodicloadcasetoproduceamaximumpossibledisplacement.


Thefollowinginputillustratessomeoftheoutputoptions.Twoloadcases,onecorrespondingtothetimeofmaximumbaseshearandonecorrespondingtothetimeofmaximumoverturningmoment,arecreated.BaseandoverturningmomenttimehistoriesaretobeplottedinadditiontoreportingthemaximumX,YandZjointdisplacements.



2.3.3Engine/CompressorVibration

Theengineorcompressorvibrationanalysisdeterminesjointdisplacementduetounbalancedforces.Jointdisplacementscanbecomparedversusvariousallowabledeflectionspecificationsandexpressedasdisplacementunitycheckratios.

AnalysisType

TheanalysislabelENGVmustbeenteredincolumns710ontheDROPTlineforengineorcompressorvibrationanalysis.

LoadOptions

Engineunbalancedloadingisenteredintheformofmechanicalunbalancedforces,gastorquesorgeneralunbalancedforces.LoadingandloadoptionsaredefinedusingtheENGVIB,RSPEEDandUNBALlinesfollowingtheLOADheaderline.

Note:EachsetofloadingrequiresaseparatesetofRSPEEDandUNBALlines.

DampingMethod

OnlystructuraldampinginputontheSDAMPlineisconsideredforenginevibrationanalyis.

Note:Becausefluiddampingisnotsupported,theFDAMPlineshouldnotbeusedforenginevibration.

EngineSpeedParameters

EnginespeedparametersaredesignatedontheENGVIBline.Thebeginningspeed(thelowestspeed)andtheendingspeed(thehighestspeed)arespecifiedincolumns713and1420,respectively.

Therunningspeedrangeisdefinedbythebeginningandendingspeeds.Theprogramdividesthespeedrangeintoincrementsforthepurposeoftheanalysisusingeitherconstantincrementsorvaryingincrementsbasedonmodalfrequencies.Specifyoneofthefollowingincrementationmethodsincolumns2123:

CONConstantincrementation

MODIncrementsvariedsoeachmodalfrequencyisincludedasananlaysisspeed

MAHSameasMODexceptthateachharmonicfrequencyisalsoincluded



USRAnalysisspeedsdefinedbytheuserusingUSRSPlines

Forconstantincrements,thespeedincrementvalueenteredincolumns2428isthetotalnumberofspeedpointstoanalyze.Forvaryingincrementsontheotherhand,thevalueenteredinthesecolumnsisusedtodeterminethesmallestspeedincrementallowedbetweenmodes.

Thefollowingshowstheinputforabeginspeedof100rpmandendingspeedof500rpmusingconstantspeedincrements.

UserdefinedrunningspeedsarespecifiedusingtheUSRspeedoptionontheENGVIBlineandUSRSPlinesimmediatelyfollowingtheENGVIBline.Forexample,thefollowinginputdesignatesanalysisrunningspeedsof120,150,200,300,and400rpm.

NonlinearInterpolationPower

Bydefault,2.0isusedasthenonlinearinterpolationpower.Enterthenonlinearinterpolationpoweroverridetobeusedforanymechanicalunbalancedforcesinterpolatednonlinearlybetweenrunningspeedsincolumns2933.Iftheinterpolationpowerisp,thentheinterpolationisaccomplishedasfollows:

whereFaretheforcesandaretherunningspeeds.Thisfieldmaybeleftblankiflinearinterpolationisusedforallunbalancedforces.

CalculationPointsperCycle

Bydefault,10pointsarecalculatedforthehighestharmonicdetermined.Thisvaluemaybeoverriddenbyspecifyingthemaximumnumberofpointscalculatedforthe



highestharmonicincolumns3739ontheENGVIBline.

Twentypointsarecalculatedforonecycleofthefundamentalfrequencybydefault.Entertheminimumnumberofpointstobecalculatedpercycleincolumns3436ifthisvalueistobeoverridden.

Note:Ifharmonicsareencountered,thenumberofpointscalculatedpercycleisthemaximumofthenumberofpointsperfundamentalandthenumberofpointscalculatedperharmonic.

AllowableOption

Thedeflectionsdeterminedbytheprogramcanbecomparedtopublishedallowabledeflectionsandexpressedasdisplacementunitycheckratios.Theallowableoptionisspecifiedincolumns4041asfollows:

DLDLineAllowable

SNSNAME

MLUSMilitarySpecification

VEMaximumVelocity

ThefollowingillustratestheinputrequiredfordisplacementunitycheckratiostobedeterminedusingtheDLineallowables.

IftheallowableoptionisVE(maximumvelocity),themaximumvelocityallowedisenteredincolumns4246.

JointSelection

Bydefault,alljointsaremonitoredintheenginevibrationanalysis.JointsmaybeoptionallyselectedtobeincludedusingtheJNTSELline.Forexample,thefollowingdesignatesthatonlyjoints101,103,105,107,109and111aretobemonitoredintheanalysis.



Note:AsmanyJNTSELlinesasrequiredmaybeused.IfJNTSELlinesarespecified,onlyjointsspecifiedaremonitoredduringtheanalysis.

UnbalancedForceInput

Engineunbalancedforcesmaybeexpressedintermsofgastorques,mechanicalunbalancedforcesand/orgeneralunbalancedperiodicforcesatvariousrunningspeeds.

Foraparticularrunningspeed,unbalancedforcescanbeinputasseparateloadconditionswheremaximumresponsefromeachisaddedand/ormaybespecifiedinthesameloadconditionifphaseanglesbetweenunbalancedforcesisknown.

EachloadconditionthatunbalancedforcesaretobedefinedisdesignatedbyaRSPEEDlinewiththerunningspeeddesignatedincolumns915.

GasTorqueLoading

Unbalancedforcesduetogastorquemaybeexpressedasmaximumgastorqueatvariousharmonicsorintheformofatotalgastorquecurve.

Whenunbalancedforcesduetogastorqueareknownforvariousharmonics,loadingisspecifiedintheformofaperiodicloadingusingUNBALlinesspecifiedimmediatelyaftertheRSPEEDline.

Thejointtowhichtheloadisappliedisdesignatedincolumns811.TheforcetypeSINisusedforloaddescribedbyasinglesinewave(amplitudeandphaseangle)andmustbedesignatedincolumns1214.Theforcesactingonthejointaredesignatedincolumns1758.

Enterthephaseangleincolumns5965,theinterpolationtype,eitherLNorNL,incolumns6667andtheharmonicnumberincolumns6869.

Theprogramallowsloadingtobegroupedandconsiderseachloadgrouptoactindependently.Themaximumdisplacementsresultingfromeachloadgrouparesummedtogethertodeterminethetotaldisplacement.Theloadgrouptowhichthisforceisassignedisstipulatedincolumns7071.

Forexample,agastorqueabouttheglobalXaxisatjoint107isknownforthefirst3harmonicsatarunningspeedof300rpm.Sincephasingisknown,eachvalueistobeassignedtothesameloadgroup,loadgroup1.Linearinterpolationistobeusedbetweenrunningspeeds.



AtotalgastorquecurvemaybeinputasaseriesofequallyspacedpointsintimeusinganUNBALlineandLDFACTlinesimmediatelyaftertheRSPEEDline.

Thejointtowhichtheloadisappliedisdesignatedincolumns811.TheforceoptionTIM,designatingforceinputbyaseriesofequallyspacedtimepoints,mustbedesignatedincolumns1214.Theappliedforcesactingonthejointaredesignatedincolumns1758.

Entertheinterpolationtype,eitherLNorNL,incolumns6667andthehighestharmonicnumbertobeusedfromtheFourierseriesincolumns7273.Theloadgrouptowhichthisforceisassignedisstipulatedincolumns7071.

Note:TheharmonicnumberandphaseanglefieldsmustbeleftblankwheninputtingloaddescribedbyequallyspacedtimepointsasdesignatedbytheTIMforceoption.

ThefollowingexampleshowsatotalgastorquecurveformomentabouttheglobalXaxisatjoint107definedat300rpm.Thecurvewillbedefinedat18degreeincrements(20points).Eachvalueonthecurveistobeassignedtothesameloadgroup,loadgroup1.Linearinterpolationistobeusedbetweenrunningspeedsandthehighestharmonicnumbertobeusedis10.

MechanicalUnbalancedForces



MechanicalunbalancedforcesarespecifiedintheformofaperiodicloadingusingUNBALlinesspecifiedimmediatelyaftertheRSPEEDline.

Thejointtowhichtheforcesareappliedisdesignatedincolumns811.TheforcetypeSINisusedforloaddescribedbyasinglesinewave(amplitudeandphaseangle)andmustbedesignatedincolumns1214.Theforcesactingonthejointaredesignatedincolumns1758.

Enterthephaseangleincolumns5965,theinterpolationtype,eitherLNorNL,incolumns6667andtheharmonicnumberincolumns6869.

Theprogramallowsloadingtobegroupedandconsiderseachloadgrouptoactindependently.Themaximumdisplacementsresultingfromeachloadgrouparesummedtogethertodeterminethetotaldisplacement.Theloadgrouptowhichthisforceisassignedisstipulatedincolumns7071.

Forexample,acompressorhasprimaryandsecondarymechanicalunbalancedforcesthatcreatemomentsabouttheglobalYandZaxeswhicharephased90degreesapart.At300rpms,theprimaryandsecondaryunbalancedforcescreate16000inkipand2600inkipmomentsabouttheYaxisand2400inkipand750inkipmomentsabouttheZaxisrespectively,appliedatjoint107.Becausetheunbalancedforcesareassumedtovarywiththesquareoftherunningspeed,nonlinearinterpolationwithapowerof2istobeused.

GeneralUnbalancedPeriodicForces

Generalunbalancedforcesmaybeinputintheformoftimehistoryorperiodicloading.

Whenunbalancedforcesareknownforvariousharmonics,loadingisspecifiedintheformsinewavesofaknownamplitudeandphaseangleusingUNBALlinesspecifiedimmediatelyaftertheRSPEEDline.UnbalancedforcesmayalsobeinputintheformofatimehistorywithequallyspacedtimepointsusinganUNBALlineandLDFACTlines.

Ineithercase,thejointtowhichtheloadisappliedisdesignatedincolumns811.Theforcetype,eitherSINforsinglesinewaveorTIMfortimehistory,mustbedesignatedincolumns1214.Theforcesactingonthejointaredesignatedincolumns1758.

Singlesinewavetypeloadingrequiresthephaseangleincolumns5965andtheharmonicnumberincolumns6869whilethetimehistorytyperequiresonlythehighestharmonictobeusedfromtheFourierseriesincolumns7273.



Theinterpolationtype,eitherLNorNL,mustbedesignatedincolumns6667.Theloadgrouptowhichthisforceisassignedisstipulatedincolumns7071.

Note:Theprogramallowsloadingtobegroupedandconsiderseachloadgrouptoactindependently.Themaximumdisplacementsresultingfromeachloadgrouparesummedtogethertodeterminethetotaldisplacement.

ThefollowingillustratesanunbalancedforcealongtheglobalZandabouttheglobalXaxisatjoint107.Theforceisknownforthefirst3harmonicsatarunningspeedof300rpmandeachvalueistobeassignedtothesameloadgroup,loadgroup1.Linearinterpolationistobeusedbetweenrunningspeeds.

ThefollowingexampleshowsaforcetimehistoryinputformomentabouttheglobalXaxisatjoint107definedat300rpm.Thecurvewillbedefinedat18degreeincrements(20points).Eachvalueonthecurveistobeassignedtothesameloadgroup,loadgroup1.Linearinterpolationistobeusedbetweenrunningspeedsandthehighestharmonicnumbertobeusedis10.

OutputOptions

Theenginevibrationanalysiscalculatesgeneralizedforcesandjointdisplacementsforthevariousconditionsdefined.Jointdisplacementsmaybecomparedtoallowabledisplacementcurvesandexpressedintermsofadisplacementunitycheckratio.



GeneralizedForces

Generalizedforceprintoptionsaredesignatedincolumns5354ontheENGVIBline.EnterPTforthestandardgeneralizedforceprintorFLforafullprint.

JointResults

JointresultsforalljointsthatexceedtheallowabledisplacementatanyrunningspeedmaybeprintedbyspecifyingPTincolumns5758ontheENGVIBline.

JointdisplacementsmayalsobeplottedbyspecifyingPLincolumns5556.Bedefault,alljointsareplottedwhenthejointplotfeatureisinstigated.JointstobeplottedmaybedesignatedusingtheJNTPLTlinefollowingtheENGVIBline.

Forexample,thefollowingdesignatesthatjointresultsaretobeplottedforjoints101,103,105and107.

PlotOptions

OptionalplotoptionsmaybedesignatedusingthePLTOPTline.Uptothreeallowablecurvesmaybeplottedonthejointdisplacementplots.Designatetheallowablecurvestobeplottedincolumns1116asfollows:

DLDLineAllowable

SNSNAME

MLUSMilitarySpecification

EnterGRincolumns3536ifgridlinesaretobeincludedontheplots.Plotsizeandcharactersizesmayalsobespecifiedincolumns1734.

Thefollowingillustratestheinputtoplotjointresultsforjoints101,103,105and107.DLineandSNAMEallowablecurvesaretobeshownalongwithgridlines.



2.4SPECTRALWINDANALYSIS

TheDynamicResponseprogramhastheabilitytoperformspectralwindanalyses.Theprogramhasspecializedfeaturesthatgeneratesolutionfilesforextremewindanalysisandwindfatigueanalysis.

2.4.1ExtremeWind

TheprogramcanbeusedtoanalyzewinddynamicallyutilizingaHarriswindspectrumandcreateasolutionfilecontainingendforces,stresses,reactionsanddisplacementsforeachwindvelocitytobeanalyzed.Theseresultscontaindynamicamplificationandcanbecombinedwiththestaticresultsduetoselfweight,etc.

GeneratingthedynamicresultsrequiresthataerodynamicdataandthewindvelocitiestobeanalyzedbespecifiedintheSeastateinput(orSACSmodelfile)whileallotherdataincludinganalysis,spectrumandplotoptionsaredesignatedintheDynamicResponseinputfile.

GeneralModelOptions

TheJOoptionwhichdesignatesthatonlystressesatthejointsaretobecontainedinthesolutionfileshouldbedesignatedincolumns2728ontheOPTIONSlineintheSACSmodelfile.Foreachelement,thedynamicamplificationfactorisbasedonthestressintheelementandisafunctionofthedynamicRMSstressandthestaticstress.Becauseeachmemberinternalloadwillbefactoredbyauniquedynamicamplificationfactorapplicableonlytothatparticularinternalload,internalloadsarenotconsistentwitheachothernoraretheyconsistentwiththeappliedloadingalongthemember.Therefore,stressesandunitycheckcalculationsareonlyvalidatthememberends.

Note:Forextremespectralwindanalysis,theanalysisoptionincolumns1920oftheOPTIONSlineshouldbeleftblank.ThedynamicanalysisoptionDYshouldNOTbespecified.

AerodynamicandWindData

AerodynamicandwinddatamustbespecifiedintheSeastateinputorSACSmodelfile.

TheWINSeastateoptionmustbespecifiedincolumns5658ontheLDOPTline.WindloaddataisspecifiedaftertheLOADline.Eachloadcasedefinedshouldcontainonlywindloadingwiththemeanwindvelocityspecifiedasthewindspeed.



Note:Eachwindshouldbespecifiedasaseparateloadcase.Asmanywindspeedsanddirectionsasdesiredmaybespecified.

Thefollowingsampleinputshowstwowindcaseswithameanvelocityof100forthe0degreeand90degreedirections.

DynamicResponseOptions

DynamicresponseoptionsincludinganalysisandplotoptionsaredesignatesintheDynamicResponseinputfile.

AnalysisType

TheanalysislabelWINDmustbeenteredincolumns710ontheDROPTlineforspectralwindanalysis.

DampingMethod

OnlystructuraldampinginputontheSDAMPlineisconsideredforspectralwindanalyis.

Note:Becausefluiddampingisnotsupported,theFDAMPlineshouldnotbeusedforspectralwindanalysis.

SpectralWindData



SpectralwinddataisspecifiedontheSPCWINlineimmediatelyfollowingtheLOADheader.DesignatetheextremewindanalysisoptionEXincolumns89.

Bydefault,600secondsisusedasthemeanwindspeedaveragingtimeusedtocalculatethedynamicamplificationfactors.Thisvaluemaybeoverriddenbyenteringanaveragingtimeoverrideincolumns3944.

Foreachwindspeedtobeanalyzed,aHarriswindspectrumiscreatedbasedonthewindvelocityatthereferenceheightalongwiththespectrumreferencelengthandsurfaceroughnessparametersinputbytheuser.TheprogramusesthisgeneratedHarrisspectrumtodeterminemodelresponses.EnterthereferencelengthandsurfaceroughnesstobeusedfortheHarrisspectrumincolumns4550and5156,respectively.

Bydefault,theprogramcalculatesthespatialcorrelationconstant,enterSKincolumns3536ifaspatialcorrelationconstantisnottobeused.

Thefollowingshowstheinputforaspectralextremewindanalysis.Defaultvaluesforwindaveragingtime,Harrisspectrumreferencelengthandroughnesscoefficientaretobeused.

OutputOptions

Bydefaulttheprogramcreatesacommonsolutionfilecontainingendforces,stresses,reactionsanddisplacementsforeachwindloadcasespecifiedintheSeastateinputfile.

Theprogramalsohastheabilitytoplotageneralizedforcespectrumand/oraresponsespectrumforeachwindspeed.EnterPLincolumns1415and1718respectivelytooutputgeneralizedforceandresponsespectra.

Entertheprintleveldesiredincolumns1112asfollows:

MNMinimumprintcontainingonelineofoutputforeachwindspeedanalyzed

MDModerateprintlevelcontainingonepageofoutputforeachwindanalyzed

MXMaximumprintcontainingdetailedoutputincludingspectrumforeachwindanalyzed.

Static+WindCombinations



TheDynamicResponsehastheabilitytooptionallycombinespectralwindresultswithstaticresultsaspartoftheextremewindanalysis.Whenusingthisfeature,theprogramcreatesawind+staticcombinationforeachwindloadcase.Ifadifferentjointcheckandmembercheckfactorsarespecifiedhowever,twocombinationsarecreatedforeachwindloadcase.

Note:Thisfeaturerequiresthatthestaticsolutionfileexistpriortoexecutionofthespectralwindanalysis.

ThewindandstaticcombinationinformationisinputusingtheSTCMBline.Enterthefactortobeappliedtothewindloadswhencombinedwiththestaticloadsforthepurposeofmemberandplateelementcheckincolumns812.Thefactortobeappliedtowindloadswhencombinedwithstaticloadsforjointcheckisinputincolumns1317.Entereachofthestaticloadcasestobecombinedwiththeseismicloadcasesandtheloadfactortobeapplied.

Forexample,105%ofloadcases8and9containedinthestaticsolutionfilearetobecombinedwiththewindsolution.Forsamefactorwindloadcasefactorisusedforelementcheckandjointcancheck.

Note:TheSTCMBlineshouldfollowtheSDAMP,FDAMPandMODSELlinesintheinputfile.

CombiningwithStaticResultsManually

Theprogramcreatesacommonsolutionfilecontainingendforces,stresses,reactionsanddisplacementsforeachwindloadcasespecifiedintheSeastateinputfile.BecausetheseresultsareobtainedbycombiningmodalresultsusingRMStechniques,endforces,stresses,etc.havenosignassociatedandaretakenasallpositivevalues.Therefore,whencombiningspectralwindresultswithstaticresultsmanually,thePRSTandPRSCcombineoptionsmustbeused.

2.4.2WindFatigue

TheDynamicResponseprogramcanbeusedtoperformspectralwindfatigueanalysisutilizingaHarriswindspectrum.TheprogramcreatesaFatigueinputfilecontainingfatigueloaddatainconjunctionwiththemodeparticipationfactorsandexecutestheFatiguemoduleautomatically.

GeneratingthedynamicresultsrequiresthataerodynamicandwindinformationbespecifiedintheSeastateinput(orSACSmodelfile)whileallotherdataincludinganalysis,spectrum,fatigueandplotoptionsaredesignatedintheDynamicResponseinputfile.

AerodynamicandWindData

AerodynamicandwinddatamustbespecifiedintheSeastateinputorSACSmodelfile.



TheWINSeastateoptionmustbespecifiedincolumns5658ontheLDOPTline.WindloaddataisspecifiedaftertheLOADline.Eachloadcasedefinedshouldcontainonlywindloadingwiththemeanwindvelocityspecifiedasthewindspeed.Windloadcasesshouldbespecifiedinorderofincreasingwindspeed,withallwindcasesforaparticulardirectionspecifiedfollowedbyallwindloadcasesforthenextdirection.

Thewindloadsspecifiedareusedtodeterminethefatiguedamage.Astressrangeiscalculatedoreachwindspeedspecified.TheHarrisspectrumisthenusedtodeterminetheprobabiltyofoccurrenceofthatspeed.

Note:Eachwindshouldbespecifiedasaseparateloadcase.Asmanywindspeedsanddirectionsasdesiredmaybespecified.

Thefollowingsampleinputshowswindloadcaseswithspeedrangingfrom2to20fortwodifferentdirections.



Note:Allwindcasesarespecifiedinthe0degreedirectionbeforethe90degreewindcasesareinput.

DynamicResponseOptions

Dynamicresponseoptionsincludinganalysis,fatigueandplotoptionsaredesignatedintheDynamicResponseinputfile.

AnalysisType

TheanalysislabelWINDmustbeenteredincolumns710ontheDROPTlineforspectralwindanalysis.

DampingMethod

OnlystructuraldampinginputontheSDAMPlineisconsideredforspectralwindanalyis.

Note:Becausefluiddampingisnotsupported,theFDAMPlineshouldnotbeusedforspectralwindanalysis.

SpectralWindData

SpectralwinddataisspecifiedontheSPCWINlineimmediatelyfollowingtheLOADheader.DesignatethewindfatigueanalysisoptionFTincolumns89.

Bydefault,600secondsisusedasthemeanwindspeedaveragingtimeusedtocalculatethedynamicamplificationfactors.Thisvaluemaybeoverriddenbyenteringanaveragingtimeoverrideincolumns3944.TheprogramusesaHarriswindspectrumtodeterminemodalresponses.EnterthereferencelengthandsurfaceroughnesstobeusedfortheHarrisspectrumincolumns4550and5156,respectively.



Thefollowingshowstheinputforaspectralwindfatigueanalysis.Defaultvaluesforwindaveragingtime,Harrisspectrumreferencelengthandroughnesscoefficientaretobeused.

OutputOptions

TheprogramcreatesaFatigueinputfilecontainingfatigueloaddataforeachwinddirectionspecifiedintheSeastateinputfile.

Theprogramalsohastheabilitytoplotageneralizedforcespectrumand/oraresponsespectrumforeachwindspeed.EnterPLincolumns1415and1718respectivelytooutputgeneralizedforceandresponsespectra.

Entertheprintleveldesiredincolumns1112asfollows:

MNMinimumprintcontainingonelineofoutputforeachwindspeedanalyzed

MDModerateprintlevelcontainingonepageofoutputforeachwindanalyzed

MXMaximumprintcontainingdetailedoutputincludingspectrumforeachwindanalyzed.

FatigueInputData

TheDynamicResponseprogramcreatestheinputfilerequiredbytheFatigueprogrammodule.FatigueinputoptionsarespecifieddirectlyintheDynamicResponseinputfilefollowingtheSPCWINline.AllFatigueinputissupportedandmaybespecifieduptothepointofdefiningfatigueloadcasedata.FatigueloadcasedataiscreatedbytheprogramautomaticallybasedonwindspectrumoptionsspecifiedbytheuserontheWINSPClines.

Foreachwinddirection,windspectrumdatausedtocreatethemodalparticipationinputandthefatigueloadcaseinputisspecifiedonthecorrespondingWINSPCline.Thewinddirectionisdesignatedincolumns713alongwiththefractionoftimethatwindfromthisdirectionoccursspecifiedincolumns1420.

TheWeibullspectrumlabelWEIisenteredincolumns2224alongwiththedistrubutionparametersKandAincolumns2632and3339,respectively.

ThefollowingillustratestheinputrequiredtogeneratetheFatigueinputfortwowinddirections,0and90degrees.Windsfrom0degreesoccur45%andwindsfrom90degreesoccur55%asdesignatedontheWINSPClines.



Note:EachwinddirectionistreatedasaseparatefatigueloadconditionandmustbedesignatedwithaWINSPCline.

2.5ICEFORCEANALYSIS

IceFatigue

TheDynamicResponseprogramcanbeusedtodeterminefatigueduetovibrationscausedbyiceforces.TheprogramcreatesaFatigueinputfilecontainingfatigueloaddatainconjunctionwiththemodeparticipationfactorsandexecutestheFatiguemoduleautomatically.

AnalysisType

TheanalysislabelVIBRmustbeenteredincolumns710ontheDROPT.Foricevibrationanalysis,enterICEincolumns710ontheFVIBline.

LoadOptions

IceloadingandloadoptionsaredefinedusingtheFVIBandICEinputlinesspecifiedaftertheLOADheaderline.EffectivediameteroverridesusedtocalculateiceloadingmaybespecifiedusingGRPMDandMEMMDlines.

DampingMethod

SpecifythedampingtypeSDOstructuraldampingonly,LFDlinearizedfluiddampingorNFDfornonlinearfluiddampingincolumns1719ontheFVIBline.

Note:Fornonlinearfluiddamping,thefluidforcesarecalculatedateverytimestepduringtheintegration.Thisoptionrequirestheprogramcalculatedfluiddamping



optionPContheFDAMPline.


EffectiveDiameterOverrides

TheeffectivediameterofmembersthatpenetratetheicesheetmaybeoverriddenusingtheMEMMDortheGRPMDlinesfollowingtheFVIBline.

Formembergroups,enterthegroupnameandtheeffectivediameterontheGRPMDline.Formemberstobemodified,enterthestartjoint,endjointandeffectivediameterontheMEMMDline.

Forexample,groupPL1,PL2andPL3representpilesinsideofthejacketlegthatpenetratetheicesheet.Theeffectivediameterismodifiedto0.001sothatnoiceloadingisappliedtomembersassignedtothesegroups.


IntegrationparametersarestipulatedontheTIMEline.Enterthestartforthebeginningofthetimeintegrationincolumns1120andtheendtimeincolumns2130.Theoutputtimeinterval,minimumintegrationstepandthetolerancefactoraredesignatedincolumns3140,4150and5160,respectively.

Forexample,thefollowingdescribesanicefunctionspecifiedintheinputfile.Thestarttimeis0secondsandendtime25seconds.Outputisrequestedatevery0.25seconds.

FatigueInputData



TheDynamicResponseprogramcreatestheinputfilerequiredbytheFatigueprogrammodule.FatigueinputoptionsarespecifieddirectlyintheDynamicResponseinputfilefollowingtheFVIBorTIMEline.AllFatigueinputissupportedandmaybespecifieduptothepointofdefiningfatigueloadcasedata.FatigueloadcasedataiscreatedbytheprogramautomaticallybasedonicedataspecifiedbytheuserontheICElines.

ThefollowingshowsfatigueinputoptionscopiedintotheFatigueinputfilecreatedbytheprogram.

IceData

Foreachicefloe,theicedatausedtocreatethemodalparticipationinputandthefatigueloadcaseinputisspecifiedonthecorrespondingICEline.Eachicefloeistreatedasanindividualfatigueloadcase.

Theicethickness,elasticmodulus,staticcrushingstrengthandtopoficeelevationarespecifiedincolumns813,1419,2025and3237,respectively.

Therationoftotallengthtoelasticlengthmustbedesignatedincolumns2631whilethefloedensityisdesignatedincolumns5055.

Theicestiffnessparameterusedtoestimatethestiffnessoftheiceisinputincolumns5661.Thedefaultvalue0.0315representsaninfinitesheetoficeflowingpastaverticalcylinder.

Entertheicevelocityorthevelocityofthefirststepifusingmultiplesteps,incolumns4449.Ifusingmultiplestepstoobtainavariationofresultswithicevelocity,enterthevelocitystepsizeincolumns6267.Thenumberofstepsshouldbestipulatedincolumns6870.

Thetimedurationenteredincolumns7176isthedurationofthefloeandisusedtodeterminethenumberofcyclesfordamagecalculations.

Thefollowingexample,shows5.0thickicefloeinthe40.0degreedirectionwithvelocitiesrangingfrom0.10to0.35.



OutputOptions

TheicevibrationanalysiscreatesaFatigueinputfileinadditiontooptionalmodalresponseoutput.Optionaloutputoptionsaredesignatedincolumns3258ontheFVIBline.

ModalResponseData



2.6DYNAMICIMPACTANALYSIS

TheDynamicResponseprogramcanbeusedtodeterminethetransientresponseofastructureresultingfromaccidentalimpactloading.Accidentalimpactloadingresultingfromafloatingvesselanddroppedobjectsareconsidered.TheprogramcanoutputequivalentstaticloadsatdiscreettimestepstobeusedforasubsequentstaticanalysisorincrementalloadsforasubsequentCollapseanalysis.AnalysistypeandanalysisoutputoptionsaredesignatedintheDynamicinputfileinadditiontothebasicanalysisoptions.

2.6.1AnalysisType



Enter'SHIP'incolumns710ontheDROPTlinetodesignateashipimpactanalysisorenter'DROP'todesignateadroppedobjectanalysis.

2.6.2LoadOptions

ForsshipimpactoradroppedobjectanalysistheinputloadingandloadoptionsareinputfollowingtheLOADheaderlineusingtheSHIP,DRPOBJandTHLOADinputlines.

2.6.3ShipImpactAnalysis

Forashipimpactanalysis,entertheshipparametersincludingtheshipweight,initialvelocity,direction,distancebeforeimpact,impactangle,coefficientoffrictionbetweentheshipandthestructureandtheimpactjointnumberontheSHIPinputlinetogetherwith'SHIP'incolumns912oftheTHLOADlinetodesignateatimehistoryshipimpactanalysis.

2.6.4DroppedObjectAnalysis

Toconductadroppedobjectanalysis,entertheobjectweight,initialvelocity,distancebeforeimpactandtheimpactjointnameontheDRPOBJinputlinetogetherwith'DROP'incolumns912oftheTHLOADlinetodesignatetimehistorydroppedobjectanalysis.

2.6.5DampingMethod

GeneraltimehistoryoptionsaredesignatedontheTHLOADlineimmediatelyfollowingtheLOADheader.SpecifythedampingtypeSDOstructuraldampingonly,LFDlinearizedfluiddampingorNFDfornonlinearfluiddampingincolumns1820.



2.6.6InterpolationScheme

Themethodusedtointerpolatebetweentimehistoryinputvaluesisdesignatedincolumns2930ontheTHLOADinputline.EnterLN,QDorCUforlinear,quadraticorcubicinterpolation,respectively.

2.6.7IntegrationParameters


Forexample,thefollowingdescribesantimehistoryfunctionspecifiedintheinputfile.StructuraldampingonlyisusedinconjunctionwithlinearinterpolationasdesignatedontheTHLOADline.Onetimehistoryfunctionisusedwithdirectionalityfactorsof1.0,1.0and0.5appliedtoitfortheX,YandZdirections,respectively.Thestarttimeis0secondsandendtime25seconds.Outputisrequestedatevery0.25seconds.



2.6.8OutputOptions

Thetimehistoryearthquakeanalysiscreatesloadcases,printsandplotsmodalresponses,baseshearandoverturningmomentinadditiontojointaccelerations,velocitiesanddisplacements.Analysisoutputoptionsaredesignatedintheoutputoptionsfieldsincolumns3359ontheTHLOADline.

2.6.9LoadCaseCreation

TheDynamicResponseprogramhastheabilitytocreatealoadcasecorrespondingtothetimepointhavingmaximumoverturningmomentand/ormaximumbaseshearbyspecifyingMXMorMXSintheoutputoptionsfieldsontheTHLOADline,respectively.EnterALLifloadcasesaretobecreatedatforalltimepoints,enter'ESL'togenerateequivalentstaticloadsfrasubsequentstaticanalysis,enter'CLP'togenerateincrementalloadsforaCollapseanalysis.

Note:the'ESL'andthe'CLP'optionsaremutuallyexclusive.

2.6.10ModalResponseData

Modalresponsesversustimemaybeprintedand/orplottedbyspecifyingPRTandPLT,respectively,intheoutputoptionsfieldsontheTHLOADline.

2.6.11BaseShearandOverturningMomentPlots

BaseshearandoverturningmomentplotsmaybegeneratedbyenteringPLMandPLSinoneoftheoutputoptionfieldslocatedontheTHLOADline.

2.6.12JointResults

Jointresultsincludingacceleration,velocityanddisplacementmaybeplottedandlistedforuptosixteenjoints.JointplotoptionsarespecifiedintheoutputoptionsfieldsontheTHLOADline.


















Anynumberofjointsmaybedesignatedforplotsandreports.JointstobeoutputarespecifiedusingJTNUMlinesimmediatelyfollowingtheTHLOADline.

Thefollowingillustratesatypicaldynamicresponseinputforashipimpactanalysis.Theanalysisoptionissetto'SHIP'ontheDROPTline.Structuraldampingof5percentisassignedontheSDAMPinputline.TheSHIPlinedescribesa1250tonneshipwithaninitialvelocityof6knotstravellingina180degreedirection.Thedistancebetweentheshipandthestructureisgivenas1meter.TheoutputloadoptionontheTHLOADlineissettogenerateincrementalloadingforaCollapseanalysis.Theresultsareoutputforjoints31P7and701ontheJTNUMline.Theanalysisstarttimeissetto0secondsandtheendtimeissetto2.0secondsontheTIMEinputline.Theresultsareoutputatevery0.01seconds.



Thefollowingexampleillustratesatypicaldroppedobjectanalysis.Theanalysisoptionissetto'DROP'ontheDROPTline.Structuraldampingof5%isassignedontheSDAMPinputline.Theweightoftheobjectisdefinedas5tonnesontheDRPOBJline.Theinitialvelocityoftheobjectisdefinedas0meterspersecondsandthedistancebeforeimpactisassignedas5meters.Theimpactjointisdefinedas3218.TheoutputloadoptionissettogenerateincrementalloadingforaCollapseanalysisbyentering'CLP'incolumns5153oftheTHLOADline.Resultsareoutputforjoint3218ontheJTNUMline.

3.0COMMENTARY

3.1BASEDRIVENSYSTEM

Theprimarypurposeofthedeflectiondrivensystemistocalculatethestructuralresponseduetoearthquakes.Forthispurpose,allsupportpointsareassumedtobemovingwiththeground.Sinceamodalanalysisisbeingused,eachmodecanbeconsideredtoactindependentlyoftheothermodesandcanbeshowntoactasasingledegreeoffreedomsystemasfollows:



Theforcedeflectionrelationforanelasticlinearstructurecanbeexpressedas:

(1)

where{F}istheforcevector,[K]islinearstiffnessmatrixand{d}isthedeformationvector.

Separatingthefreeandthereactiondegreesoffreedom,theforcedeflectionrelationcanbeexpressedas:

(2)

wheretheFandRsubscriptsdifferentiatethefreeandreactiondegreesoffreedom.

Forabasedrivensystem,theloadinginthefreedegreesoffreedomisduetotheinertiaandcanbeexpressedas:

(3)

wheredFaretheaccelerationsofthefreedegreesoffreedomandMFFisthemassmatrix.

Fromequation(2),

(4)

whichbecomes:

(5)

Thedeformationofafreedegreeoffreedomcanbeexpressedintermsofdeformationduetoexternalloadsanddeformationduetomovementofthesupports,sothat

(6)

wheredFEisduetoexternalloadsanddFSisduetomovementofthesupports.Equation(4)becomes

(7)

bydefinition

(8)



sothat

(9)

or

(10)

Substituting(10)into(6)yieldsthefollowing:

(11)

Differentiatingbothsidestwicewithrespecttotime,produces

(12)

Substitutingequation(11)and(12)intoequation(5),

(13)

Thedeformationofthefreedegreesoffreedomwiththebasefixedcanbeexpressedintermsofthenormalvibrationmodesoftherestrainedstructuresuchthat

(14)

whereFFaremodeshapesandrepresentsmodalcoordinates.Substitutingequation(14)intoequation(13)yieldsthefollowing:

(15)

Notingthattheeigenvalues/vectorrelationofthemassmatrix,

(16)

wherenarethenaturalfrequenciesoftherestrainedstructure,substituting(16)into(15)andmultiplyingbythemodeshapes,

(17)



Notingthatthegeneralizedmassisexpressedas:

(18)

equation(17)becomes:

(19)

or

(20)

DefiningtheparameterRas

(21)

equation(20)maybeexpressedas:

(22)

Modaldampingcanbeaddedsot

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