简介:Moleculardynamics(MD)simulationswereperformedtostretchtherectangulargraphenesheetsdopedwithsilicon,nitrogenorboronatoms.Young’smodulus,ultimatestress(strain)andenergyabsorptionweremeasuredforthegraphenesheetswiththedopingconcentration(DC)rangingfrom0to5%.Theemphasiswasplacedonthedistincteffectsofeachindividualdopantonthefundamentalmechanicalpropertiesofgraphene.TheresultsindicatedthatincorporatingthedopantsintographeneledtoanalmostlineardecreaseinYoung’smodulus.Monotonicreductionsinultimatestrength,ultimatestrainandenergyabsorptionwerealsoobserved.Suchdopingeffectswerefoundtobemostsignificantforsilicon,lesspronouncedforboron,andsmallornegligiblefornitrogen.Theoutputsprovideanimportantguidanceforthedevelopmentandoptimizationofnovelnanoscaledevices,andfacilitatethedevelopmentofgraphene-basedM/NEMS.
简介:Toconsidertheanisotropicdamageinfatigue,animprovedboom-panelmodelispresentedtosimulatearepresentativevolumeelement(RVE)intheframeworkofcontinuumdamagemechanics.TheanisotropicdamagestateoftheRVEisdescribedbythecontinuityextentsofboomsandpanels,whosedamageevolutionsareassumedtobeisotropic.Thenumericalimplementationisproposedonthebasisofdamagemechanicsandthefiniteelementmethod.Finally,theapproachisappliedtothefatiguelifepredictionof2A12-T4aluminiumalloyspecimenundercyclicloadingoftension-torsion.Theresultsindicateagoodagreementwiththeexperimentaldata.