2DsimulationoftheinitiationandpropagationofcrackarrayunderthermalfatigueOriginalResearchArticle

Variouscomponentsofnuclearreactorsaresubmittedtovariousthermo-mechanicalloadings.Thermalfatiguecrackinghasbeenclearlydetectedinreactorheatremovalsystem(RHRS)ofpressurizedwaterreactors(PWRs).ThepresentstudyfocusesonAISI304LstainlesssteelusedinPWRs.Thethermalfatiguebehaviorofthissteelhasbeeninvestigatedusingaspecificthermalfatiguefacilitycalled“SPLASH”.Thistestequipmentallowsthereproductionofmultiplecracknetworkssimilartothosedetectedduringcomponentinspections.Thepresentstudydealswiththemodelingofcracknetworksinitiationandpropagation.Itisstructuredintwoparts:(i)experimentaldetailsandmaincharacteristicsofthecracksnetworks,and(ii)numericalsimulationofmultiplecracksinitiationandgrowthproblem,usinganelastic–plasticthermal–mechanicalcomputationandageneralizedParis’law.Themodelpresentedinthisstudygivespredictionsinagoodagreementwithobservations,asfarastheevolutionofthemeananddeepestcracksduringcyclingisconcerned.