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1、ProductsofLORDAudiTT(￥400,000-700,000)AudiR8(￥2320,000-2780,000)BuickLucerne(￥300,000-500,000)Ferrari599GTB(￥5000,000)HoldenHSVCommodore(￥1200,000-2000,000)地勢MRF-122EG Magneto-RheologicalFluid?FastResponseTime–respondsinstantlyandreversiblytochangesinamagneticfield.?DynamicYieldStrength–provides
2、highyieldstrengthinthepresenceofamagneticfieldandverylowyieldstrengthintheabsenceofamagneticfield;allowsforawiderangeofcontrollability. ?TemperatureResistant–performsconsistentlythroughoutabroadtemperaturerange,meetingtherequirementsofdemandingapplicationssuchasautomotiveshockabsorbers. ?HardS
3、ettlingResistant–provideshighresistancetohardsettling;easilyredispersed(重分散). ?Non-Abrasive(零磨損)–formulatedtonotabrade(損傷)thedevicesinwhichtheMRfluidisused.FeaturesandBenefitsWhataremagnetorheologicalfluids?Magnetorheologicalfluidsbelongtothegroupofsocalledcontrollablefluids.Thismeansthattheyex
4、hibitasignificantchangeintheirrheologicalbehaviourwhenanexternalmagneticfield(外部磁場)isappliedtothem.Theyareindeedcomposedofmicron-sizedmagneticparticles(微米級磁粒),locatedinsidealiquidcarrier,thatformchain-likestructureswhentheexternalmagneticfieldisapplied,resultinginanincreaseoftheapparentviscosity
5、(粘性)ofthefluid(Fig.1and2).Fig.1:Chain-likestructuresformationintheMRfluidunder anexternallyappliedmagneticfield(fromLORDcorporation)Fig.2:ChainsformationinadropofMRfluid(fromISCFraunhofer)TherheologicalbehaviourofMRfluidsisoftenrepresentedasaBinghamplasticmodelwithavariableyieldstrengthdepending
6、ontheappliedmagneticfieldH(Fig.3aand3b).Theflowisgovernedbytheequation:whereistheshearstress,istheshearstrainandistheviscosityofthefluid.TheoperatingrangeistheshadedareainFig.3c.Belowtheyieldstress(atstrainsoftheorderof10-3),theMRfluidbehavesviscoelastically:WhereGisthecomplexmaterialmodulus.Thi
7、smodelisalsoagoodapproximationforMRdevices.However,theactualbehaviourismorecomplicatedandincludesstiction(靜摩擦)andhysteresis(磁滯現(xiàn)象)suchsuchasshowninFig.3.dFig.3:(a)and(b)Binghamplasticmodel,(c)Operatingrange,(d)Hystereticbehav
