




已閱讀5頁(yè),還剩7頁(yè)未讀, 繼續(xù)免費(fèi)閱讀
版權(quán)說(shuō)明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請(qǐng)進(jìn)行舉報(bào)或認(rèn)領(lǐng)
文檔簡(jiǎn)介
1|PageCopyrighte-Xstreamengineering,2009Multi-ScaleModelingofCompositeMaterialsandStructureswithDIGIMATtoANSYSDocumentVersion1.0,February2009Copyright,e-Xstreamengineering,2009infoe-Xwww.e-XMaterials:EngineeringPlastics,ReinforcedPlastics.e-XstreamTechnology:DIGIMAT,Digimat-MF,Digimat-FE,DigimattoANSYS,MAP.ComplementaryCAETechnology:Moldflow,Moldex3D,SigmaSoft,ANSYS.Industry:MaterialSuppliers,Automotive,Aerospace,Consumer&IndustrialProducts.TABLEOFCONTENTEXECUTIVESUMMARY.2MaterialMulti-ScaleModeling:anintroduction.2FEHomogenization:anapplicationtonanocomposites.5ModelingFillerClustering,atypicalnanoeffect.5ResultComparison.7FE/MFHCoupledComputation:anapplicationtoanindustrialpart.9ProblemDescription.9MaterialModeling.10SimulationResults.11Bibliography.12LegalNotice.eX,eXdigimatande-Xstreamengineeringareregisteredtrademarksofe-XstreamengineeringSA.Theotherproductandcompanynamesandlogosaretrademarksorregisteredtrademarksoftheirrespectiveowners.2|PageCopyrighte-Xstreamengineering,2009EXECUTIVESUMMARYInthispaper,webrieflyintroducetwomulti-scalemodelingapproaches,namelytheMean-Field(MFH)andFiniteElementHomogenization(FEH)methods.Thesepowerfultechniquesrelatethemicroscopicandmacroscopicstressandstrainfieldswhenmodelingmaterialbehaviorsandhencecancapturetheinfluenceofthematerialmicrostructure(i.e.fiberorientation,fibercontent,fiberlength,etc.)onitsmacroscopicresponse.Toillustratethesetechniques,wealsopresent(i)anapplicationoffiniteelementhomogenizationtoananostructureand(ii)thestudyofaninjectedglassfiberreinforcedplasticneonlightclaspusingfiniteelementcomputationsatthemacroscalecoupledwithMFhomogenizationatthemicroscale.MaterialMulti-ScaleModeling:anintroductionAsamotivatingexample,letusconsideraplasticpartmadeupofathermoplasticpolymerreinforcedwithshortglassfibers.Astypicaloftheinjectionmoldingmanufacturingprocess,thefiberdistributioninsidethefinalproductwillvarywidelyintermsoforientationandlength,seeFigure1.Thecompositematerialwillbebothanisotropicandheterogeneous,whichmakesitextremelydifficulttoperformareliablesimulationoftheproductusingaclassicalapproachbasedonmacroscopicconstitutivemodels.However,apredictivesimulationispossibleviaamulti-scaleapproach,whichcanbedescribedinarathergeneralsettingasfollows.Figure1:Fiberorientationdistributioninaninjectedglassfiber-reinforcedplasticclutchpedal.CourtesyofRhodia&Trelleborg.Letusstudyaheterogeneoussolidbodywhosemicrostructureconsistsofamatrixmaterialandmultiplephasesofso-called“inclusions”,whichcanbeshortfibers,platelets,particles,micro-cavitiesormicro-cracks.Ourobjectiveistopredicttheresponseofthebodyundergivenloadsandboundaryconditions(BCs),basedonitsmicrostructure.Wecandistinguishtwoscales,themicroscopicandmacroscopiclevels,respectively.Theformercorrespondstothescaleoftheheterogeneities,whileatthemacroscale,thesolidcanbeseenaslocallyhomogeneous;seeFigure2.Inpractice,itwouldbecomputationallyimpossibletosolvethemechanicalproblematthefinemicroscale.Therefore,weconsiderthemacroscaleandassumethateachmaterialpointisthecenterofarepresentativevolumeelement(RVE),whichcontainstheunderlyingheterogeneousmicrostructure.Classicalsolidmechanicsanalysisiscarriedoutatthemacroscale,exceptthatateachcomputationpoint,strainorstressvaluesaretransmittedasBCstotheunderlyingRVE.Inotherwords,anumericalzoomisrealizedateachmacropoint.TheRVEproblemsaresolvedandeachofthemreturnsstressandstiffnessvalues,whichareusedatthemacroscale.3|PageCopyrighte-Xstreamengineering,2009Figure2:Illustrationofthemulti-scalematerialmodelingapproach,afterNemat-NasserandHori(1).Nowtheonlydifficultyinthistwo-scales(andmoregenerallymulti-scale)approachistosolvetheRVEproblems.ItcanbeshownthatforaRVEunderclassicalBCs,themacrostrainsandstressesareequaltothevolumeaveragesovertheRVEoftheunknownmicrostrainandstressfieldsinsidetheRVE.Inlinearelasticity,relatingthosetwomeanvaluesgivestheeffectiveoroverallstiffnessofthecompositeatthemacroscale.InordertosolvetheRVEproblem,onecanusethewell-knownfiniteelement(FE)method,seeFigures7to10.Thismethodofferstheadvantagesofbeingverygeneralandextremelyaccurate.However,ithastwomajordrawbackswhichare:seriousmeshingdifficultiesforrealisticmicrostructuresandalargeCPUtimefornonlinearproblems,suchasforinelasticmaterialbehaviour.Anothercompletelydifferentmethodismean-fieldhomogenization(MFH),whichisbasedonassumedrelationsbetweenvolumeaveragesofstressorstrainfieldsineachphaseofaRVE;seeFigure3.ComparedtothedirectFEmethod,andactuallytoallotherexistingscaletransitionmethods,MFHisboththeeasiesttouseandthefastestintermsofCPUtime.However,twoshortcomingsofMFHarethatitisunabletogivedetailedstrainandstressfieldsineachphaseanditisrestrictedtoellipsoidalinclusionshapes.Figure3:Mean-fieldhomogenizationprocess:(i)localstrainsarecomputedbasedonthemacrostrains,(ii)localstressesarecomputedbasedonthelocalstrainsandaccordingtoeachphaseconstitutivemodel,and(iii)macrostressesarecomputedbyaveragingthelocalstresses.4|PageCopyrighte-Xstreamengineering,2009AtypicalexampleofMFHistheMori-Tanakamodel(2)whichissuccessfullyapplicabletotwo-phasecompositeswithidenticalandalignedellipsoidalinclusions.ThemodelassumesthateachinclusionoftheRVEbehavesasifitwerealoneinaninfinitebodymadeoftherealmatrixmaterial.TheBCsinthesingleinclusionproblemcorrespondtothevolumeaverageofthestrainfieldinthematrixphaseoftherealRVE.ThesingleinclusionproblemwassolvedanalyticallybyJ.D.Eshelby(3)inalandmarkpaper,whichisthecornerstoneofMFHmodels.Figure4:SchematicoftheMori-Tanakahomogenizationprocedure.Mori-TanakaandotherMFHmodelsweregeneralizedtoothercases,suchasthermoelasticcoupling,two-phasecompositeswithmisalignedfibers(usingamulti-stepapproach)ormulti-phasecomposites(usingamulti-levelmethod).ThepredictionshavebeenextensivelyverifiedagainstdirectFEsimulationofRVEsorvalidatedagainstexperimentalresults.Asageneralconclusion,itwasfoundthatinlinear(thermo)elasticity,MFHcangiveextremelyaccuratepredictionsofeffectiveproperties,althoughfordistributedorientations,progressinclosureapproximationwillbewelcomed.NotealsothatMFHcanbeusedforUD,andforeachyarninwovencomposites.AnimportantandstillongoingeffortbothintheoreticalmodelingandincomputationalmethodsisthegeneralizationofMFHtothematerialorgeometricnonlinearrealms.Suchextensioninvolvessomemajordifficulties.Thefirstoneislinearization,whereconstitutiveequationsatmicroscaleneedtobelinearizedontolinearelastic-orthermoelastic-likeformat.Thesecondissueisthedefinitionofso-calledcomparisonmaterialswhicharefictitiousmaterialsdesignedtopossessuniforminstantaneousstiffnessoperatorsi
溫馨提示
- 1. 本站所有資源如無(wú)特殊說(shuō)明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請(qǐng)下載最新的WinRAR軟件解壓。
- 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請(qǐng)聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
- 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁(yè)內(nèi)容里面會(huì)有圖紙預(yù)覽,若沒(méi)有圖紙預(yù)覽就沒(méi)有圖紙。
- 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
- 5. 人人文庫(kù)網(wǎng)僅提供信息存儲(chǔ)空間,僅對(duì)用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對(duì)用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對(duì)任何下載內(nèi)容負(fù)責(zé)。
- 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請(qǐng)與我們聯(lián)系,我們立即糾正。
- 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶因使用這些下載資源對(duì)自己和他人造成任何形式的傷害或損失。
最新文檔
- 高效救援演練的應(yīng)急處置與快速響應(yīng)能力提升
- 貴州省六盤(pán)水市第二十中學(xué)2024年化學(xué)九年級(jí)第一學(xué)期期末監(jiān)測(cè)模擬試題含解析
- 2025至2030肝硬化治療行業(yè)產(chǎn)業(yè)運(yùn)行態(tài)勢(shì)及投資規(guī)劃深度研究報(bào)告
- 四川省成都市天府第七中學(xué)2024-2025學(xué)年八年級(jí)數(shù)學(xué)第一學(xué)期期末調(diào)研試題含解析
- 常州勞動(dòng)合同試用期管理規(guī)范
- 交通事故理賠催告函模板定制合同
- 網(wǎng)絡(luò)直播產(chǎn)業(yè)發(fā)展計(jì)劃及盈利模式探索報(bào)告
- 中國(guó)汽車拆解行業(yè)自動(dòng)化改造的市場(chǎng)趨勢(shì)預(yù)測(cè)報(bào)告
- 環(huán)保創(chuàng)意大賽組織流程
- 2025至2030中國(guó)自動(dòng)紙箱封口機(jī)行業(yè)市場(chǎng)深度研究及發(fā)展前景投資可行性分析報(bào)告
- 高速公路施工安全培訓(xùn)課件
- 2024年中級(jí)經(jīng)濟(jì)師考試經(jīng)濟(jì)基礎(chǔ)知識(shí)必考重點(diǎn)總結(jié)全覆蓋
- 轉(zhuǎn)崗人員安全知識(shí)培訓(xùn)
- 寧夏石嘴山市礦業(yè)(集團(tuán))有限責(zé)任公司招聘筆試題庫(kù)2024
- 網(wǎng)絡(luò)設(shè)備安裝調(diào)試作業(yè)指導(dǎo)書(shū)
- 鐵嶺三支一扶真題2023
- 2024年省石棉縣人力資源和社會(huì)保障局關(guān)于公開(kāi)考核招考綜合類事業(yè)單位工作人員高頻考題難、易錯(cuò)點(diǎn)模擬試題(共500題)附帶答案詳解
- 人工智能數(shù)據(jù)標(biāo)注 課件
- 骨折病的中醫(yī)分型及治療
- (高清版)TDT 1068-2022 國(guó)土空間生態(tài)保護(hù)修復(fù)工程實(shí)施方案編制規(guī)程
- 路面橋梁搶修知識(shí)培訓(xùn)課件
評(píng)論
0/150
提交評(píng)論