StressAnalysisandOptimumDesignofHotExtrusionDiesAbstract:Athree-dimensionalmodelofahotextrusiondiewasdevelopedbyusingANSYSsoftwareanditsseconddevelopmentlanguage—ANSYSparametricdesignlanguage.Afiniteelementanalysisandoptimumdesignwerecarriedout.Thethree-dimensionalstressdiagramshowsthatthestressconcentrationisrathersevereinthebridgeofthehotextrusiondie,andthatthestressdistributionisveryuneven.Theoptimumdimensionsareobtained.Theresultsshowthattheoptimumheightoftheextrusiondieis89.596mm.Theoptimumradiiofdiffluenceholesare65.048mmand80.065mm.Thestressconcentrationisreducedby27%.Keywords:three-dimensionalmethod;modeling;hotextrusiondie;optimumdesignIntroductionWiththecontinuousimprovementoflivingstandards,betterthermalconductivityofaluminumalloyprofiles.Aluminumcomponentswidelyusedineveryaspectoflife.Therefore,thealuminumalloyextrusionprofiles,profilesofvarioustypesofradiatorshavebeenwidelyusedinelectricalappliances,machinery,andotherindustries.Variableproductsandthegrowingdiversityandcomplexityofhigh-precision,theextrusionprocessisthebasisforextrusiondie.Itnotonlydeterminestheshape,size,accuracyandsurfacestate,butalsoaffecttheperformanceoftheproduct.Soextrusiondieextrusiontechnologyisthekey.Studiestoimproveextrusiondiequalityandprolongitslifespanusuallyattempttosimplify3-Dfiniteelementmodelto2-D,butitisonlyrightforsimplestructuralshapes.Withouta3-Dfiniteelementanalysis,theresultscannotgivepracticalmanufacturinghelpandofferusefulinformation[3-5].Inthispaper,aluminiumprofileextrusiondiewasmodeledtogetinoptimumdesign[6-8].1SolidModelingFigure1showsthemaledieofahotextrusionplanarcombineddie.Itsexternaldiameteris227.000mm,itsheightis80.000mm.OtherparametersareshowninFig.1.Themodelingmethodisasfollows.1.1CoordinatesofP1andP5ThecoordinatesofthepointofintersectionbetweenthebeelineL(y=kx+b)andthecirculararc(x2+y2=R2)are1.2CoordinatesofP2andP6Thecoordinatesoftheintersectionpoint(P2)betweenbeelineL1(y=kx+b)andbeelineL2(y=S1)are1/11Thecoordinatesoftheintersectionpoint(P6)betweenbeelineL3(y=kx+b)andbeelineL4(y=S1)are1.3CoordinatesofP3,P4,P7,andP8P3andP1aresymmetricaboutthey-axis.P4andP2arealsosymmetricaboutthey-axis.P7andP5aresymmetricaboutthex-axis.P8andP6arealsosymmetricaboutthex-axis.1.4VariablesintheequationsInEqs.(1)-(6),forpointsP1andP2,andR=R1.ForpointsP5andP6,andR=R2.R1,R2,T1,T2,S1,andS2arethechangerulealongtheheight(H)ofthedieexpressedasthefunctionsR1=f1(z),R2=f2(z),T1=f3(z),T2=f4(z),S1=f5(z),andS2=f6(z),z€[0,H].1.5SectionshapeatsomeheightWithlineslinkingP1-P4,P5-P8,withcirculararcfilletingatthepointofintersection(P1-P8),thesectionshapeatsomeheightisobtained.1.6SectionshapeateveryheightHisdividedtointerfacialnumber(INUM)equalparts(INUMisdecidedbytheprecision,iftheINUMishigher,theprecisionisbetter).ThesectionshapeisdrawnateveryheightasshowninFig.2.2/111.7SmoothcurvedsurfaceUsingSKINcommandinANSYS,smoothcurvedsurfaceswerebuiltalongthelines.Theyarethesurfacesoftheinfluencehole.UsingtheVA(itgeneratesavolumeboundedbyexistingarea)command,asolidwascreatedfromthosesurfaces.1.8SymmetryofthedieThemainbodyandkernelofthedieweredrawnusingtheBooleanoperationsofadd,subtract,etc.(Fig.3).Thesymmetryofthediewasusedtoacceleratethecomputationsusinga1/4-solidmodelforthefiniteelementanalysis(Fig.4).2ComputingModelAplanardiethatextrudesthealuminiumalloy(6063Al-Mg-Si)wasusedasanexample.Theliquidoid...