外文翻译单浇口优化注塑模英文版.pdf

JournalofZhejiangUniversitySCIENCEAISSN1673-565X(Print)；ISSN1862-1775(Online)wwwzjueducnjzus；wwwspringerlinkcomE-mail：jzuszjueducaLfefalJZhejiangUnivSciA20078(7)：1077·1083SinglegateoptimizationforplasticinjectionmoldLIJi-quan十，LIDequn，GUOZhiying，LVHaiyuan(DepartmentofPlasticityTechnology,ShanghaiJiaoTongUniversity，Shanghai200030,China)Email：hutli163cornReceivedNov22，2006；revisionacceptedMar19，20071077Abstract：ThispaperdealswithamethodologyforsinglegatelocationoptimizationforplasticinjectionmoldTheobjectiveofthegateoptimizationistominimizethewarpageofinjectionmoldedparts，becausewarpageisacrucialqualityissueformostinjectionmoldedpartswhileitisinfluencedgreatlybythegatelocationFeaturewarpageisdefinedastheratioofmaximumdisplacementonthefeaturesurfacetotheprojectedlengthofthefeaturesurfacetodescribepartwarpageTheoptimizationiscombinedwiththenumericalsimulationtechnologytofindtheoptimalgatelocation，inwhichthesimulatedannealingalgorithmisusedtosearchfortheoptimumFinally，anexampleisdiscussedinthepaperanditcanbeconcludedthattheproposedmethodiseffectiveKeywords：Injectionmold，Gatelocation，Optimization，Featurewarpagedoi：101631jzus2007A1077Documentcode：ACLCnumber：TQ32066INTRODUCTIONPlasticinjectionmoldingisawidelyusedcomplexbuthighlyefficienttechniqueforproducingalargevarietyofplasticproducts，particularlythosewithhighproductionrequirement，tighttolerance，andcomplexshapesThequalityofinjectionmoldedpartsisafunctionofplasticmaterial，partgeometry，moldstructureandprocessconditionsThemostimportantpartofaninjectionmoldbasicallyisthefollowingthreesetsofcomponents：cavities，gatesandrunners，andcoolingsystemLamandSeow(2000)andJinandLain(2002)achievedcavitybalancingbyvaryingthewallthicknessofthepartAbalancefillingprocesswithinthecavitygivesanevenlydistributedpressureandtemperaturewhichcandrasticallyreducethewarpageofthepartButthecavitybalancingisonlyoneoftheimportantinfluencingfactorsofpartqualitiesEspecially。theparthasitsfunctionalrequirementsanditsthicknessesshouldnotbevariedusuallyProject(No50675080)supportedbytheNationalNaturalScienceFoundationofChinaFromthepointviewoftheinjectionmolddesign，agateischaracterizedbyitssizeandlocationandtherunnersystembythesizeandlayoutThegatesizeandruIlllerlayoutareusuallydeterminedasconstantsRelatively，gatelocationsandrunnersizesaremoreflexiblewhichcanbevariedtoinfluencethequalityofthepartAsaresult，theyareoftenthedesignparametersforoptimizationLeeandKimrl996a)optimizedthesizesofrunnersandgatestobalancerunnersystemformultipleinjectioncavitiesTherunnerbalancingwasdescribedasthedifferencesofentrancepressuresforamulticavitymoldwithidenticalcavitiesandasdifferencesofpressuresattheendofthemeltflowpathineachcavityforafamilymoldwimdifferentcavityvolumesandgeometriesThemethodologyhasshownuniformpressuredistributionsamongthecavitiesduringtheentiremoldingcycleofmultiplecavitiesmoldZhaieta1(2005a1presentedthetwogatelocationoptimizationofonemoldingcavitybyanef前一cientsearchmethodbasedonpressuregradient(PGSS)，andsubsequentlypositionedweldlinestothedesiredlocationsbyvaryingrunnersizesfor维普资讯http:/www.cqvip.com1078L，ea1dZhejiangUnivSciA20078(7)：1077-1083multigateparts(Zhaieta1，2006)Aslargevolumepart，multiplegatesareneededtoshortenthemaximumflowpath，withacorrespondingdecreaseininjectionpressureThemethodispromisingfordesignofgatesandrunnersforasinglecavitywichmultiplegatesManyofinjectionmoldedpartsareproducedwithonegatewhetherinsinglecavitymoldorinmultiplecavitiesmoldThereforethegatelocationofasinglegateisthemostcommondesignparameterforoptimizationAshapeanalysisapproachwaspresentedbyCOHrbebaisseandGarcia(2002)，bywhichthebestgatelocationofiniectionmoldingwasestimatedSubsequently，theydevelopedthismethodo1ogyfurtherandappliedittosinglegatelocationoptimizationofanLshapeexample(Courbebaisse，2005)Itiseasytouseandnottimeconsumingwhileitonlyservestheturningofsimpleflatpartswichuniforii1thicknessPandelidisandZour1990)presentedtheoptimizationofgatelocationbyindirectqualitymeasuresrelevanttowarpageandmaterialdegradationwhichisrepresentedasweightedsumofatemperaturedif-ferentialtermanoverpacktermandafrictionaloverheatingtermWarpageisinfluencedbytheabovefactorsbuttherelationshipbetweenthemisnotclearTherefore，theoptimizationeffectisrestrictedbythedeterminationoftheweightingfactorsLeeandKimrl996b)developedanautomatedselectionmethodofgatelocation，inwhichasetofinitialgatelocationswereproposedbyadesignerandthentheoptimalgatewaslocatedbytheaacentnodeevaluationmethodTheconclusiontoagreatextentdependsmuchonthehumandesignersintuitionbecausethefirststepofthemethodisbasedonthedesignerspropositionSotheresultistoalargeextentlimitedtothedesignersexperienceLamandJin(200l、developedagatelocationoptimizationmethodbasedontheminimizationoftheStandardDeviationofFlowPathLength(SDL)andStandardDeviationofFillingTime(SDT)duringthemoldingfillingprocessSubsequently，Shenet口，004a；2004b)optimizedthegatelocationdesignbyminimizingtheweightedsumoffillingpressure，fillingtimedifferencebetweendifferentflowpaths，temperaturedifference，andoverpackpercentageZhaieta1(2005b)investigatedoptimalgatelocationwithevaluationcriteriaofiniectionpressureattheendoffillingTheseresearcherspresentedtheobiectivefunctionsasperformancesofiniectionmoldingfillingoperation，whicharecorrelatedwithproductqualitiesButthecorrelationbetweentheperforii1ancesandqualitiesisverycomplicatedandnoclearrelationshiphasbeenobservedbetweenthemyetItisalsodifficulttoselectappropriateweightingfactorsforeachtermAnewobjectivefunctionispresentedheretoevaluatethewarpageofinjectionmoldedpartstooptimizegatelocationTomeasurepartqualitydirectly，thisinvestigationdefinesfeaturewarpagetoevaluatepartwarpage，whichisevaluatedfromthe“flowpluswarpagesimulationoutputsofMoldflowPlasticsInsight(MPI)softwareTheobjectivefunctionisminimizedtoachieveminimumdeformationingatelocationoptimizationSimulatedannealingalgorithmisemployedtosearchfortheoptimalgatelocationAnexampleisgiventoillustratetheeffectivityoftheproposedoptimizationprocedureQUALITYMEASURES：FEATUREWARPGEDefinitionoffeaturewarpageToapplyoptimizationtheorytothegatedesign，qualitymeasuresofthepartmustbespecifiedinthefirstinstanceTheterm“quality”maybereferredtomanyproductproperties，suchasmechanical，thermal，electrical，optical，ergonomicalorgeometricalpropertiesTherearetwotypesofpartqualitymeasures：directandindirectAmodelthatpredictsthepropertiesfromnumericalsimulationresultswouldbecharacterizedasadirectqualitymeasureIncontrastanindirectmeasureofpartqualityiscorrelatedwithtargetquality，butitcannotprovideadirectestimateOfchatqualityForwarpage，theindirectqualitymeasuresinrelatedworksareoneofperformancesofiniectionmoldingflowingbehaviororweightedsumofthoseTheperformancesarepresentedasfillingtimedif-ferentialalongdifferentflowpathstemperaturedif-ferential，overpackpercentage，andsoonItisobviousthatwarpageisinfluencedbytheseperforii1ances，buttherelationshipbetweenwarpageandtheseperformancesisnotclearandthedeterminationoftheseweightingfactorsisratherdifficultThereforetheoptimizationwiththeaboveObiectivefunction维普资讯http:/www.cqvip.comLfefalJZhejiangUnivSciA20078(：1077-1083probablywillnotminimizepartwarpageevenwithperfectoptimizationtechniqueSometimes，improperweightingfactorswillresultinabsolutelywrongresultsSomestatisticalquantitiescalculatedfromthenodaldisplacementswerecharacterizedasdirectqualitymeasurestoachieveminimumdeformationinrelatedoptimizationstudiesThestatisticalquantitiesareusuallyamaximumnodaldisplacement，anaverageoftop10percentilenodaldisplacements，andanoverallaveragenodaldisplacement(LeeandKim，l995；I996b)ThesenodaIdisplacementsareeasytoobtainfromthesimulationresults，thestatisticalvalues，tosomeextents，representingthedeformationButthestatisticaldisplacementcannoteffectivelydescribethedeformationofthein_iectionmoldedpartsInindustrydesignersandmanufacturersusuallypaymoreattentiontothedegreeofpartwarpageonsomespecificfeaturesthanthewholedeformationofthein，_iectionmoldedpartsInthisstudyfeaturewarpageisdefinedtodescribethedeformationoftheinjectionpartsThefeaturewarpageistheratioofthemaximumdisplacementofthefeaturesurfacetotheprojectedlengthofthefeaturesurface(Fig1)：_h×100，Lwhereyisthefeaturewarpage，histhemaximumdisplacementonthefeaturesurfacedeviatingfromthereferenceplatform，andListheprojectedlengthofthefeaturesurfaceonareferencedirectionparallelingthereferenceplatformSurfaceceplaneFig1ThedefinitionoffeaturewarpageForcomplicatedfeatures(onlyplanefeaturediscussedhere)，thefeaturewarpageisusuallyseparatedintotwoconstituentsonthereferenceplane，whicharerepresentedona2Dcoordinatesystem：=h×l0=×l00oo，1079where，yyaretheconstituentfeaturewarpagesintheXYdirectionandLx，LaretheprojectedlengthsofthefeaturesurfaceonYcomponentEvaluationoffeaturewarpageAtierthedeterminationoftargetfeaturecombinedwithcorrespondingreferenceplaneandproiectiondirection，thevalueofLcanbecalculatedimmediatelyfromthepartwiththecalculatingmethodofanalyticgeometry(Fig2)LisaconstantforanypartonthespecifiedfeaturesurfaceandproiecteddirectionButtheevaluationofhismorecomplicatedthanthatofLyFeatureFig2TheprojectedlengthevaluationSimulationofiniectionmoldingprocessisacommontechniquetoforecastthequalityofpartdesign，molddesignandprocesssettingsTheresultsofwarpagesimulationareexpressedasthenodaldeflectionsonZcomponent(，)，andthenodaldisplacementWisthevectorlengthofvectorsumof，andWzk，where，karetheunitvectorsonZcomponentThehisthemaximumdisplacementofthenodesonthefeaturesurface，whichiscorrelatedwiththenormalorientationofthereferenceplane，andcanbederivedfromtheresultsofwarpagesimulationTocalculatehthedeflectionoffthnodeisevaluatedfirstlyasfollows：=COSO+cosfl+W,zcosy一(+)，(3)whereisthedeflectioninthenormaldirectionofthereferenceplaneofithnode；W，WI1、，WizarethedeflectionsonX，Y，Zcomponentofithnode；伐，B，aretheanglesofnormalvectorofthereference；AandBaretheterminalnodesofthefeaturetoproiectingdirection(Fig2)；andarethedeflectionsofnodesAand：维普资讯http:/www.cqvip.com1080LfefaldZhefiangUnivSciA20078(1077-1083f=COSa+cosfl+：cosy，lCOSa+cosfl+Gzcosy，whereWA，WAy，：arethedeflectionsonZcomponentofnode；Wsx，andWezarethedeflectionsonX，Y，ZcomponentofnodeCOiAandlBaretheweightingfactorsoftheterminalnodedeflectionscalculatedasfollows：(2)iA=1一LiAL，co=1一(J)iA，whereLiAistheprojectordistancebetweenfthnodeandnodeAUltimately，histhemaximumoftheabsolutevalueof：h=maxlI,I，1Inindustry，theinspectionofthewarpageiscarriedoutwiththehelpofafeelergauge，whilethemeasuredpartshouldbeplacedonareferenceplat-formThevalueofhisthemaximumnumericalreadingofthespacebetweenthemeasuredpartsurfaceandthereferenceplatformGATEL0CAT10N0PTIMIZAT10NPR0BLEMFORMATIONThequalityterm“warpage”meansthepermanentdeformationofthepart，whichisnotcausedbyanappliedloadItiscausedbydifferentialshrinkagethroughoutthepart，duetotheimbalanceofpolymerflow，packing，cooling，andcrystallizationTheplacementofagateinaniniectionmoldisoneofthemostimportantvariablesofthetotalmolddesignThequalityofthemoldedpartisgreatlyaf-fectedbythegatelocationbecauseitinfluencesthemannerthattheplasticf1owsintothemoldcavityTherefore，differentgatelocationsintroduceinhomogeneityinorientation，density，pressure，andtemperaturedistribution，accordinglyintroducingdifferentvalueanddistributionofwarpageThereforegatelocationisavaluabledesignvariabletominimizetheinjectionmoldedpartwarpageBecausethecorrelationbetweengatelocationandwarpagedistributionistoalargeextentindependentofthemeltandmoldtemperatureitisassumedthatthemoldingconditionsarekeptconstantinthisinvestigationTheinjectionmoldedpartwarpageisquantifiedbythefeaturewarpagewhichwasdiscussedintheprevioussectionThesinglegatelocationoptimizationcanthusbeformulatedasfo11ows：Minimize：mini(X)=)，；Subjectto：g(X)：PPo一10，XX，i=1，2，N，where)，isthefeaturewarpage；Pistheinjectionpressureatthegateposition；P0istheallowableiniectionpressureofinjectionmoldingmachineortheallowableinjectionpressurespecifiedbythedesignerormanufacturer；Xisthecoordinatevectorofthecandidategatelocations；isthenodeonthefiniteelementmeshmodelofthepartforinjectionmoldingprocesssimulation；NisthetotalnumberofnodesInthefiniteelementmeshmodelofthepart，everynodeisapossiblecandidateforagateTherefore，thetotalnumberofthepossiblegatelocationnisafunctionofthetotalnumberofnodesNandthetotalnumberofgatelocationstobeoptimized：N(N一1)(一一1)!Inthisstudy，onlythesinglegatelocationproblemisinvestigatedSIMULATEDANNEALINGALG0RITHMThesimulatedannealingalgorithmisoneofthemostpowerfulandpopularmeta-heuristicstosolveoptimizationproblemsbecauseoftheprovisionofgoodglobalsolutionstorealworldproblemsThealgorithmisbaseduponthatofMetropoliseta1(1953)，whichwasoriginallyproposedasameanstofindanequilibriumconfigurationofacollectionofatomsatagiventemperatureTheconnectionbetweenthisalgorithmandmathematicalminimizationwasfirstnotedbyPincusr1970)butitwasKirkpatricketa1(1983)whoproposedthatitformedthebasisofanoptimizationtechniqueforcombinational(andother)problemsToapplythesimulatedannealingmethodtoop维普资讯http:/www.cqvip.com