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:Theobjectiveofthisworkistoanalysefatiguereliabilityofdeckstructuressubjectedtocorrelatedcrackgrowth.Thestressintensityfactorsofthecorrelatedcracksareobtainedbyfiniteelementanalysisandbasedonwhichthegeometrycorrectionfunctionsarederived.TheMonteCarlosimulationsareappliedtopredictthestatisticaldescriptorsofcorrelatedcracksbasedontheParis-Erdoganequation.Aprobabilisticmodelofcrackgrowthasafunctionoftimeisusedtoanalysethefatiguereliabilityofdeckstructuresaccountingforthecrackpropagationcorrelation.Adeckstructureismodelledasaseriessystemofstiffenedpanels,whereastiffenedpanelisregardedasaparallelsystemcomposedofplatesandarelongitudinal.Ithasbeenproventhatthemethoddevelopedherecanbeconvenientlyappliedtoperformthefatiguereliabilityassessmentofstructuressubjectedtocorrelatedcrackgrowth.
简介:从STCW公约马尼拉修正案所规定的甲板部操作级船员最低适任要求出发,分析了海船三副的岗位职能及最低适任要求,在此基础上进行了教学内容遴选,并按项目化的设计理念重新对《驾驶台资源管理》课程内容进行了序化,提出了项目化教学实施标准的制订思路。