简介:Thepotentialbasedlowordersurfacepanelmethodisusedtopredictthehydrodynamicperformanceofmarinepropellers.Inpresentmethodthehyperboloidalquadrilateralpanelsareemployedtoavoidthegapbetweenthepanels.TheinfluencecoefficientsofpanelsarecalculatedbyMorino’sanalyticalformulationsforincreasingnumericallycalculatingspeed.Thepres-sureKuttaconditionissatisfiedonthetrailingedgeofpropellerbladebyNewton-Raphsoniterativeprocedure.Thereforethe
简介:Themostcriticalissueinthesteelcatenaryriserdesignistoevaluatethefatiguedamageinthetouchdownzoneaccurately.Appropriatemodelingoftheriser-soilresistanceinthetouchdownzonecanleadtosignificantcostreductionbyoptimizingdesign.Thispaperpresentsaplasticitymodelthatcanbeappliedtonumericallysimulateriser-soilinteractionandevaluatedynamicresponsesandthefatiguedamageofasteelcatenaryriserinthetouchdownzone.Utilizingthemodel,numerousriser-soilelementsareattachedtothesteelcatenaryriserfiniteelements,inwhicheachsimulateslocalfoundationrestraintalongtherisertouchdownzone.Theriser-soilinteractionplasticitymodelaccountsforthebehaviorwithinanallowablecombinedloadingsurface.Themodelwillberepresentedinthispaper,allowingsimplenumericalimplementation.Moreimportantly,itcanbeincorporatedwithinthestructuralanalysisofasteelcatenaryriserwiththefiniteelementmethod.Theapplicabilityofthemodelisinterpretedtheoreticallyandtheresultsareshownthroughapplicationtoanoffshore8.625″steelcatenaryriserexample.Thefatigueanalysisresultsofthelinerelasticriser-soilmodelarealsoshown.Accordingtothecomparisonresultsofthetwomodels,thefatiguelifeanalysisresultsoftheplasticityframeworkarereasonableandthehorizontaleffectsoftheriser-soilinteractioncanbeincluded.
简介:观展读史前不久,由中国博物馆协会航海博物馆专业委员会主办、中国运河文化博物馆承办的国内首届“匠心问舟——‘海上丝绸之路’中式木帆船模型展览”在山东聊城中国运河文化博物馆隆重开幕。此次中华传统木帆船船模大展,集中展示了中国历史上发明创造的各种船型,涵盖了我国传统木帆船的沙船、浙船、福船、广船等主要航海船型以及一些具有独特地域特征的“通江达海”的内河航行船型。如上海沙船、汴河客船、南湖红船、绿眉毛船、丹阳船、川江麻秧子船、山东长岛大瓜篓船、牵风船、巢湖划子船、福建泉州湾宋代海船、山东菏泽元代沉船、天津张湾明代运河漕船复原船及清代广东大澳船等。