简介:摘要:文中主要介绍了VERICUT 9.1软件中FORCE模块的优化方法方式、操作流程及基于该软件生成的优化文件在数控机床上的应用情况。VERICUT软件中FORCE模块根据加工材料、刀具、机床、参数来生成高效的数控程序,不改变原程序的运行轨迹,最终实现节省加工时间,提高生产效率,降低加工成本。
简介:Magneticforcetransmissionofareciprocatingmotionisstudiedbytheoreticalanalysisandexperiment.Amathematicalmodelforcalculatingthemagneticforceisderivedusingthetheoryofequivalentmagneticcharges.Anexperimentalrigisconstructedtotestthetransmissionandthemodelisverifiedbyexperiment.Effectofthetransmissionparametersonthemagneticforceisanalyzedtheoreticallyfromthemodel,andcharacteristicofthetransmissionisstudiedexperimentally.Sincethetransmissioniswithoutdirectcontactbetweentwoelements,itissuitableforapplicationinanorganism.
简介:IntroductionDigitalstronggroundacelerationobservationinstrument,suchasPDR1,SSA1andSSR1producedbyKinemetricsInc.,USAandSCQ?..
简介:Tochangeflightdirection,flyinganimalsmodulateaerodynamicforceeitherrelativetotheirbodiestogeneratetorqueaboutthecenterofmass,orrelativetotheflightpathtoproducecentripetalforcethatcurvesthetrajectory.Inemployingthelatter,thedirectionofaerodynamicforceremainsfixedinthebodyframeandrotationsofthebodyredirecttheforce.Whilebothaforementionedtechniquesareessentialforflight,itiscriticaltoinvestigatehowananimalbalancesthetwotoachieveaeriallocomotion.Here,wemeasuredwingandbodykinematicsofcicada(Tibicenlinnei)infreeflight,includingflightperiodsofbothlittleandsubstantialbodyreorientations.Itisfoundthatcicadasemployacommonforcevectoringtechniquetoexecutealltheseflights.Weshowthatthedirectionofthehalf-strokeaveragedaerodynamicforcerelativetothebodyisindependentofthebodyorientation,varyinginarangeofmerely20deg.Despitedirectionallimitationoftheaerodynamicforce,pitchandrolltorquearegeneratedbyalteringwingangleofattackanditsmeanpositionrelativetothecenterofmass.Thisresultsinbodyrotationswhichredirectthewingforceintheglobalframeandconsequentlychangetheflighttrajectory.
简介:Basedonthe1stordercnoidalwavetheory,thewavediffractionaroundthepiergroupinshallowwaterisstudiedinthispaper.Theformulasforcalculatingthenonlinearwaveforcesarealsopresentedhere.Inordertoverifythetheoreticalresults,modeltestsareconductedinthewaveflumeinTheStateKeyLaboratoryofCoastalandOffshoreEngineeringlocatedinDalianUniversityofTechnology.TherangeofthewaveparametersintheexperimentsischaracteristicwaveperiodTg/d1/2=8.08-22.86,characteristicwaveheightH/d=0.10.45.Theresultsobtainedfromtheexperimentsagreewiththetheoreticalresultsquitewell.Itisshownthat,inshallowwaterthenonlinearwaveforcesactingonapiergrouparegreaterthanthosecalculatedbylinearwavetheory,thevalueofincrementinwaveforceincreaseswiththeincreasesofthenonlinearityofthewave.Inthewaverangestudiedinthispaper,thenonlinearwaveforcecanreachover4timestheforcecalculatecdbylinearwavetheory.Thus,itissuggestedthat,whenTg/d1/2>8,thewaveforceonthepiersinthepiergroupinshallowwatershouldbecalculatedbyusingthecnoidalwavetheory.
简介:Amulti-functionsamplingsystemhasbeensetupinShanghaiShip&ShippingResearchInstitute(SSSRI)whereatestonthefluctuatingpressureoftwopropellermodelswerecarriedout.Thispaperdealswithastudyonthetechnicalproblemsconcerningthemeasurementandanalysistechniquesinvolvedinthetest.Thesamplingandprocessingprocedureofsignalisoneofthemajorfactorsaffectingtheac-curacyandstabilityofthepredictionoffluctuatingpressureinducedbypropeller.Integral-peri-odsampling,highenoughsamplingfrequencyandsuitableresolutionmustbekeptinsamplingandprocessing.Theprocedureofsamplingandprocessingshouldbevalidatedbystandardsignalcorrespondingtothebladefrequencyofdifferentordersincomparativetests.
简介:Thesurfacemorphologyoffree-surfacePCLringedspheruliteswasinvestigatedbyusingatomicforcemicroscopy.ThespheruliteswereobtainedbycrystallizationofPCL/PVCblendsofdifferentcompositions.Itwasfoundthattheringedspheruliteexhibitedregularlyfluctuatingringsonitssurface.Comparedwiththebright-darkringpatternofthespheruliteunderapolarizingmicroscope,itwasprovedthattheopticalcharacteristicsoftheringedspheruliteunderpolarizingmicroscopecoincidedwithitssurfacecharacteristics.Thebrightringsinpolarizingmicrographsofthespherulitecoincidedwiththeconvexringsonitssurface,whilethedarkringscoincidedwiththeconcaverings.
简介:Lineardrivingforce(LDF)modeliswidelyusedinadiffusionprocess,However,thismodelhasinherentweakness.Whenthedimensionlesstimeislessthan0.1itsrelativeerrorisupto95%.Inthispaper,anewconcentrationprofileisproposed.andthenanewmodifiedLDFmodel(MLDF)isdeduced.Comparedwiththeexactsolutionofintraparticlediffusionequation,thetransientvolume-averageamountadsorbedcalculatedfromtheMLDFismoreaccuratethanthatcalculatedfromtheLDFmodel.Ifonetakes±10%relativeerrorforthelimitofvalidityofapproximation,thenewmodelisvalidwhenthedimensionlesstimeisjustlargerthan0.0002,whiletheLDFmodelisnotvaliduntilthedimensiontimeislargethan0.05,ThenewmodelissuperiortotheLDFmodel.ThenewconcentrationprofilescorrespondingtotheMLDFmodelaremuchclosetotheexactconcentrationprofileswithinaparticlethantheparabolicprofilescorrespondingtotheLDFmodel.
简介:Mooringmodelexperimentandmooringlinetensiondeterminationareofsignificancetothedesignofmooringsystemsandberthingstructures.Thispapermainlyinvolves:(a)descriptionandanalysisofamooringmodelexperiment;(b)derivationofstaticequilibriumequationsforamooredshipsubjectedtowind,currentandwaves;(c)solutionofmo.oringequationswiththeMonteCarlomethod;(d)qualitativeanalysisofeffectsofpierpilesonmooringlineforces.Specialemphasisisplacedonthederivationofstaticequilibriumequations,solutionmethodandthemooringmodelexperiment.