简介:Carbonnanotubemacro-filmsaretwo-dimensionalfilmswithmicrometerthicknessandcentimeterbycentimeterin-planedimension.Thesecarbonnanotubemacroscopicassemblieshaveattractedsignificantattentionfromthematerialandmechanicscommunitiesrecentlybecausetheycanbeeasilyhandledandtailoredtomeetspecificengineeringneeds.Thispaperreportstheexperimentalmethodsonthepreparationandcharacterizationofsingle-walledcarbonnanotubemacro-films,andastatisticalmechanicsmodelon...
简介:Inthispaper,aclustermodelinparticleflowcodewasusedtosimulategranitespecimensafterheattreatmentunderuniaxialcompression.Theresultsdemonstratedthatmicro-cracksarerandomlydistributedinthespecimenwhenthetemperatureisbelow300?C,andhavepartialcoalescencewhenthetemperatureisupto450?C,thenformmacro-crackswhenthetemperatureisabove600?C.Thereismoreinter-granularcrackingthanintra-granularcracking,andtheirratioincreaseswithincreasingtemperature.Themicro-cracksarealmostconstantwhenthetemperaturedecreasesfrom900?Ctoroomtemperature,exceptforquartzα–βphasetransitiontemperature(573?C).Thefractureevolutionprocessisobviouslyaffectedbythesecracks,especiallyat600–900?C.Elevatedtemperatureleadstoeasilydevelopeddisplacementbetweenthegrains,andthecapacitytostorestrainenergybecomesweaker,correspondingtotheplasticityofgraniteafterheattreatment.