Inthefollowing,thetensorconceptwillbeappliedasitenablesdescribingthestressandstraincomponentsandtherelatedmathematicaloperationsontheminacompactway.Ascalarisa0thordertensor(aquantity)whereasavectorisa1stordertensor(quantityanddirection).Thestresstensorisa...[继续阅读]

    AsmentionedinSection8.1theapplicationofsoilmodelsfordescribingthelateraltransversepipe-soilinteractionbehaviourisacriticalissuewhendealingwithhightemperaturepipelinesrestingontheseabed.TraditionallysuchanalysesareperformedbyusingstandardCoulombmodelswhere...[继续阅读]

    ThereareseveralcaseswhichcanonlybemodelledbygeneralFEsoftware.Thisincludes:(1)Localizedloadsfromothermechanicaldevicessuchastensioners,caterpillars,clampsetc;(2)Bendstiffenerandendfittingdetails;(3)Redistributionofstressesduetowirefailures;(4)Bucklingeffe...[继续阅读]

    Usingtheprinciplesoutlinedin(SinesandWaisman,1959)onewayofformulatingthecriterionforamulti-axialfatiguefailurecanbestatedintermsoftheVonMisesequivalentstressrangeas:TheconstantsA,αandβcanbedeterminedfromfatiguetestingatthreedifferentmeanstresslevels,i.e.e...[继续阅读]

    1.KinematicsByneglectingsheardeformationsandendsectionwarpingandonlyconsideringthemotionofthehelixcentreline,thekinematicquantitiesgoverningthelongitudinalstrainwasformulatedbySæviksee(Sævik1993,2011)Thekinematicquantitiesofrelevancewithreferenc...[继续阅读]

    TheobjectiveofthisexampleistoinvestigatethecorrelationbetweenFEanalysisandavailabletestdata(Østergaard,2012)relatedtothelateralbucklingbehaviouroftensilearmourinflexiblepipecross-sectionsexposedtoacompressiveforceintheendsandthenexposedtocyclicbendin...[继续阅读]

    Theoverallbasisforpipelinematerialselectionistoensureeconomicandsafeproducttransport.Duringthepipelinedesignphases,thematerialengineeringincludesdifferentactivitieswheretheconceptualdesignphasenormallyfocusonidentifyingthematerialrequirementsintermsof:(1)...[继续阅读]

    Thecaseselectedrepresentstheupperhang-offsectionofaflexibleriser.Inordertocontrolthecurvatureatthehang-offsection,abendstiffenerisinmostcasesappliedontheoutsideofthepipe,aconicalcylindernormallymadeofpolyurethane.Themodelincludedtheendfittingwherethetensi...[继续阅读]

    Inordertodeterminetheinstallationforcesandassociatedstresses,thereareseveraltechniquesavailable:(1)Analyticalcalculationsbasedonthecatenaryequation;(2)Finitedifferencesolutionofthestiffenedcatenaryequation;(3)Finitedifferencesolutionofthefullnon-linearbea...[继续阅读]

    Attheouterandinnersurfacesheattransporttakesplacebyconvection.Theconvectionratewilldependontheflowphysicalpropertiesandthevelocitygoverningtheboundarylayerthicknessattheinterfaces.Theheatfluxthroughbothlayersisdefinedas:Qr＝2πrihi(Ti-Tl)=2πroho(Tn-To)(5.7)...[继续阅读]