简介:TheconstitutiveequationforasemiconcentratedfibresuspensionintheOldroyd-Bfluidhasbeenderivedfromastatisticalmodelofsuchasuspensionbyemployingthemoleculartheoryforpolymericliquids.Tocircumventtheoreticaldifficultiesinviscoelasticfluidmechanics,severalsimplifiedmodelsareusedtoaccountfortheinteractionsoffibresandpolymermolecules.Someofmaterialfunctionsarecalculatedintermsoftheconstitutiveequation.
简介:ResearcheffortsmadesofartosimulatefibresuspensionflowsarelimitedtofibresuspensionsinNewtonianfluids.Thoughshortfibrecompositesaremostlymadeofpolymers,lackofsuitableconstitutiveequationsforfibresuspensionsinviscoelasticfluidsfrustratesattemptstosimulateflowsofthesesuspensions.ApreliminaryworkdonebytheauthorledtoaconstitutiveequationforsemiconcentratedfibresuspensionsintheOldroyd-Bfluid.Thispaperdescribesthemathematicalformulationoftheflowproblemsforsuchasuspensionandthenumericalproceduretosolvethem.Somenumericalresultsofflowpastasphereinatubearealsopresented.
简介:Surfaceoriginatedkinkbandsconsistofanimportantfailuremodeforfibre-reinforcedcompo-sitesundercompression.Themechanicalbehaviorofthefibrebridgingkinkbandsisexploredhereininthecontextofthepost-microbucklingtheory.Expressionsofbridgingforceareobtainedfortheentirepostbucklingprocessofthefibresexhibitingweakorstronghardening.Thepostbucklingformulationofthefibresisappliedtoyieldthetoughnessincrementduetotheadvancingkinkbands,andconsequentlyleadstoaquantitativepre-dictionontheoverallcompressivestressstraincurvesofthefibre-reinforcedcomposites.