reading 5 On the Design of Compliant Mechanisms Us

PLEASESCROLLDOWNFORARTICLEThisarticlewasdownloadedby:[CanadianResearchKnowledgeNetwork]On:4July2010Accessdetails:AccessDetails:[subscriptionnumber918588849]PublisherTaylor&FrancisInformaLtdRegisteredinEnglandandWalesRegisteredNumber:1072954Registeredoffice:MortimerHouse,37-41MortimerStreet,LondonW1T3JH,UKMechanicsBasedDesignofStructuresandMachinesPublicationdetails,includinginstructionsforauthorsandsubscriptioninformation:~content=t713639027OntheDesignofCompliantMechanismsUsingTopologyOptimizationOleSigmundaaDEPARTMENTOFSOLIDMECHANICS,TECHNICALUNIVERSITYOFDENMARK,LYNGBY,DK,DENMARKTocitethisArticleSigmund,Ole(1997)'OntheDesignofCompliantMechanismsUsingTopologyOptimization',MechanicsBasedDesignofStructuresandMachines,25:4,493—524TolinktothisArticle:DOI:10.1080/08905459708945415URL::(4),493-524(1997)OntheDesignofCompliantMechanismsUsingTopologyOptimization*OleSigmundABSTRACTThispaperpresentsamethodforoptimaldesignofcompliantmechanismtopologies.Themethodisbasedoncontinuum-typetopologyoptimizationtech-niquesandfindstheoptimalcompliantmechanismtopologywithinagivendesigndomainandagivenpositionanddirectionofinputandoutputforces.Bycon-strainingthealloweddisplacementattheinputport,itispossibletocontrolthemaximumstresslevelinthecompliantmechanism.Theabilityofthedesignmethodtofindamechanismwithcomplexoutputbehaviorisdemonstratedbyseveralexamples.Someoftheoptimalmechanismtopologieshavebeenmanulac-tured,bothinmacroscale(hand-size)madeinNylon,andinmicroscale(Smm))madeofmicromachinedglass.I.INTRODUCTIONAcompliantmechanismisamechanismthatgainsitsmobilityfromtheflexi-bilityofsomeorallofitsmembers,asopposedtoitsmoreconventionalrigidbodycounterpart(Fig.1).Advantagesofcompliantmechanismsarethattheyrequire*CommunicatedbyP.Pedersen493CopyrightO1997byMarcelDekker,Inc.DownloadedBy:[CanadianResearchKnowledgeNetwork]At:03:554July2010494Restoringspring/fSIGMUNDFlexuralpivotFig.I.Arigidbodymechanism(left).adistributedcompliantmechanism(center).andalumpedcompliantmechanism(right).fewerparts;areeasytofabricate;havelesswear,friction,andbacklash;havenoneedforlubrication;andhavebuilt-inrestoringforce[1,2].Theconceptofcom­pliantorflexiblemechanismsisnotnew[3],butithasrecentlyreceivedincreasedattentionbecauseoftheintroductionofmaterialswithsuperiorpropertiesandtherapidlyexpandingfieldofMicroElectroMechanicalSystems(MEMS).MicroElectroMechanicalSystemsarebuiltinsub-millimeterscaleandinte­gratedwithelectroniccircuits[4].Theyaremanufacturedusingetchingtechniquesfromthesemi-conductorindustry,andarealreadywidelyusedforintegratedsensorapplications;e.g.,accelerationsensorsforairbags.Theyhavepotentialapplicationsforin-bodysurgery,healthmonitoring,micromanipulation,andnano-fabrication[5].Compliantmechanismsarewell-suitedforMEMSbecauseofthesmalllengthscaleandproblemswithfrictionandwearthatprohibituseofconventionalrigid­bodymechanisms.Becauseofthecomplexityofelasticbehaviorofcompliantmechanisms,theirdesignhastypicallybeenaccomplishedbytrialanderrormethods.However,re­searchershaveaddressedthequestionofintroducingmoresystematicdesignpro­cedures.Non-linearfiniteelementanalysisandoptimizationmethodshavebeenusedtodesignflexiblemechanismsforfunctiongeneration[I].Studies[6,7,8.9]beganbysynthesizingarigid-bodymechanism,inturnintroducingflexibilitytoobtainapseudo-rigid-bodymechanism,andfinallyanalyzingafullycompli­antmechanism.Thesedesignmethodsincludetheso-calledshootingmethodsorchain-methods.Thesynthesisproblemhasbeenconsideredinmanyotherworks.Commontoallmethods,however,isthattheyconsiderthedimensionaldesignormodificationofafixedmechanismtopology,typicallyafour-barmechanism.Aninterestingapproachtothedesignofcompliantmechanisms,whichallowsforchangeoftopology,istomakeuseoftopologyoptimizationmethods[10,IIj.Topologyoptimizationmethodswereoriginallyintendedformaximumstiffnessdesignofelasticstructures,buthasrecentlybeenextendedtothedesignofcom­pliantmechanismsbyAnathasureshetal.[12],whodemonstratedthedesignofasimplecrunchingmechanism;Sigmund[13],whodesignedgrippingmechanismsusingatrusstopologymodel;andLarsenetal.[14],whodesignedtopologicallycomplicatedmechanismswithmultipleinputandoutputportsusingacontinuum­typetopologyoptimizationmethod.DownloadedBy:[Canadia