开孔泡沫材料弹塑性行为的三维数值模拟和宏 - 中国

2005(CCTAM2005)*12111000882200240:FleckHutchinsonToupin-Mindlin(CS)(SG)GaoHuangMSGAcharyaBassaniChenWangFleck-HutchinsonC1HerrmannLagrangeC0XiaC1ShuShuC1C1Fleck-HutchinsonPianC0(150001)(quasicontinuummethodQC)QC28.2Å3000Å1500Å1500Å*(10172078,50374014)(CCTAM2005)11—234FCCQC1/11Y.-W.Mai2(1.2000922.)22d2a2lMMTplatelets6[1,2]5-663[3]66[4]Nylon-6(a)MTT[5][6]Halpin-Tsai[3]Mori-Tanaka[3]combinedparallel-seriesthree-phasemodel[7]hierarchicalmodel[8]bJäger[9]1nm750m2/g[4]/6Jäger(1a)1b/6A()BD(6)C(6)JägerFAFDFBDBA(b)CAABCDBA:∆M=KA×(FA+FAB)DB:∆N=KB×(FAB+FB)C:∆N=KC×(FA–FAB)FAFBFD(CCTAM2005)(1)∆M=KCD×FCD1(a)(b)D:∆N=KD×FD=KD×(FCD+FAB–FB)FA,FB,FC,FD,FABFCD∆M∆NBKA,KB,KC,KDKCD357911130123V%Young'sModulus(GPa)TestresultsofRef.[3]FEMStaggeredmodelofJagerPresentstaggeredmodel2/6hbElKhbEaKhlGbKhdEaKhdElKNylonCDNylonDNylonCNylonBMMTA××=××=×=××=××=2,2,2,2,2F=FA+FB+FD∆=∆M+∆NMNCDATotalTotalPNCCKKhdblalahdbFE1111)(2)()(21)(++××++=+∆×+=ACDCBDMNKKKKKC11111+++=2[3]JägerFEM6[1]Usuki,A.,Kawasumi,M.,Kojima,Y.,Okada,A.,J.Mater.Res.1993a,8:1174-1178[2]Usuki,A.,Kojima,Y.,Kawasumi,etal,J.Mater.Res.1993b,8:1179-1184[3]Fornes,T.D.,Paul,D.R.,Polymer2003,44:4993-5013.[4]Wang,J.,Pyrz,R.,Compos.Sci.Tech.2004,64:925-934[5]BruneDA,Bicerano,J.Polymer2002;43:36987.[6]KojimaY,UsukiA,KawasumiM,etal,J.Mater.Res.1993,8(5):11859.[7]JiXL,JingJK,JiangW,JiangBZ,PolymEngSci2002;42(5):983-993.[8]Wang,J.,Pyrz,R.,Compos.Sci.Tech.2004,64:935944[9]Jager,Ingomar,Fratzl,Peter,BiophysicalJournal,200079:1737-1746VIB1(200240)()VIB(VirtualSpringModel-VSM)[e-mail]@sjtu.edu.cn2005(CCTAM2005)vQHD(100871)WignerFokker-PlanckvQHD(ViscousQuantumHydrodynamic)[1]vQHD(RTDResonantTunnellingDiode)(negativedifferentialresistivity)(hysteresis)[2]vQHDvQHD1qqdivJDnq=∆122020116qqBBDqkTJJqqndivnnVnqnmkTmmn⊗∆++∇−∇−∇h0qqJDJτ=−+∆2()(divVqnCε∇=−)3Newton-RaphsonV∇V0=VU=VUvQHDNewton-RaphsonNewton-RaphsonvQHDRTDIVV∇=+[1]A.Arnold,J.A.Carrilo,andE.Dhamo.OntheperiodicWigner-Poisson-Fokker-Plancksystem.J.Math.Anal.Appl.275(2002),263-276[2]A.Juengel,andS.Tang.Numericalapproximationoftheviscousquantumhydrodynamicmodelforsemiconductors,(submitted).1000841YoungLaplace(CCTAM2005)1L2L3L4LSolidLiquidVapor1L2L3L4LSolidLiquidVapor12100084/(100871)2198010(CCTAM2005)/Eshelby/Eshelby34300742DEshelby(1983)F.C.C.B.C.C./(100084)[e-mail](CCTAM2005)*710049VoronoiVoronoiKelvinKelvinVoronoiChenLuInt.J.Solids&Struct.,2000,Vol.37,7769Chen-LuSEM1421100084220003040%1µmHall-PetchSEM1240°3451/20yykdσσ−=+*Email:[e-mail]4010-62792972;Email:[e-mail](CCTAM2005)12σ135MPa3σ163MPa4σ183MPaModelingofMechanicsofinterfaceofbiologicalnanostructuralcompositesBaohuaJi(DepartmentofEngineeringMechanics,TsinghuaUniversity,Beijing100084,China)Abstract:Organic-inorganichybridbiologicalcompositeshaverefinedmicrostructuresfromthenanoscaleuptothemacroscale.Wehavepreviouslystudiedthefracturestrengthofnanometersizedmineralplatelet,andfoundthatthemineralplateletcanholdthetheoreticalstrengthofmineralatthenanoscaleevenwiththepresenceofflaws.However,wearenotclearabouttheinterfacestrengthbetweenproteinandmineralandhowthelengthscaleinfluencestheirinterfacestrength.Inthiswork,Itrytostudythemechanicsofinterfaceofthebiologicalmaterialsbybothcontinuummodelingandtheatomisticmodeling.Asimplefracturemodelisfirstlydevelopedbasedonatension-shearchainmodel(TSC).Themodelrevealsthattheinterfacestrengthisreverselyscalewiththesquarerootofthecharacteristicsizeofthemineralplatelet,exhibitingthesamescalinglawasthatoffracturestrengthofmineral.Inaddition,largeaspectratioofmineralplateletcanfurtherenhancetheinterfacestrength.Afterwards,anatomisticmodelisdevelopedtostudythemicro-mechanismoftheinterfacialslippingstrengthbetweenproteinandmineralattheatomisticscale.TheMDsimulationshowsthatthemacroscopicsmoothslidingbetweenproteinlayerandmineralplateletisachievedbystick-slipofsingleproteinmolecularchainsalternativelyamongthemolecules.Thereforetheinterfacestrengthisdeterminedbytheabilityofthechainmoleculesanchoringatthesubstrateataspecificinstantduringtheslippingwhichinfluencedbythetemperatureandthevelocityofslipping.TheMDsimulationalsoshowsthatthechainstructureofproteinisanimportantmechanismtoenhancethe(CCTAM2005)interfacialslippingstrengthandinterfacetoughnessofbio-nanocomposites.AcknowledgementsThisworkissupportedbytheNationalNaturalScienceFoundationofChinathroughGrantNo.10442002andNationalBasicResearchProgramofChinathroughGrantNo.2004CB619304.MechanicalTensileBehaviorandMicrostructureEvolutionforPoly(vinylidenefluoride-trifluorethylene)copolymerthinfilmsF.Fang,M.Z.Zhang,J.F.Huang(DepartmentofEngineeringMechanics,FML,TsinghuaUniversity,Beijing,China100084)Abstract:Ferroelectricmaterialsformoneimportantclassofthefunctionalmaterials.Inrecentyearstherehasbeenincreasingrecognitionoftheimportance