简介：Inordertostudybucklingpropagationmechanismindeepseapipelines,thecontactbetweenpipeline’sinnerwallsinbucklingprocesswasstudied.Atwo-dimensionalringmodelwasusedtorepresentthepipelineandanonlinearspringmodelwasadoptedtosimulatethecontactbetweeninnerwalls.Basedontheelastoplasticconstitutiverelationshipandtheprincipleofvirtualworktheory,thecouplingeffectofpipeline’snonlinearlargedeformationandwallcontactwasincludedinthetheoreticalanalysiswiththeaidofMATLAB,andtheapplicationscopeofthetheoreticalmodelwasalsodiscussed.Thecalculatedresultsshowthatduringtheloadingprocess,thechangeinexternalpressureiscloselyrelatedtothedistributionofsectionstress,andoncethewallsarecontactingeachother,theexternalpressureincreasesandthenremainsstableafteritreachesaspecificvalue.Withoutfracture,thepipelinesectionwillstopshowingdeformation.Theresultsoftheoreticalcalculationsagreewellwiththoseofnumericalsimulations.Finally,inordertoensurereliabilityandaccuracyofthetheoreticalresults,thecollapsepressureandpropagationpressurewerebothverifiedbynumericalsimulationsandexperiments.Therefore,thetheoreticalmodelcanbeusedtoanalyzepipeline’sbucklingdeformationandcontactbetweenpipeline’sinnerwalls,whichformsthebasisforfurtherresearchonthree-dimensionalbucklingpropagation.

简介：Inordertotheoreticallystudythebucklepropagationofsubseapipelineswithslip-onbucklearrestors,atwo-dimensionalringmodelwassetuptorepresentthepipelineandanonlinearspringmodelwasadoptedtosimulatethecontactbetweenpipeline’sinnerwallsandbetweenpipeline’souterwallandslip-onbucklearrestor’sinnerwallduringbucklepropagation.Inaddition,somereversespringsareaddedtopreventthewallofleftandrightsidesseparatingfromtheinnerwallofslip-onbucklearrestors.Consideringlargedeformationkinematicsrelationsandtheelastic-plasticconstitutiverelationofmaterial,balanceequationswereestablishedwiththeprincipleofvirtualwork.Thevariationofexternalpressurewithrespecttothecross-sectionalareaofpipelineswasanalyzed,andthelowerboundofthecrossoverpressureofslip-onbucklearrestorswascalculatedbasedonMaxwell’senergybalancemethod.Bycomparingthetheoreticalresultswithexperimentandfiniteelementnumericalsimulation,thetheoreticalmethodisprovedtobecorrectandreliable.