Title of article
DynamicsandgenerationofstresswavesincrackedgraphitemoderatorbricksOriginalResearchArticle
Author/Authors
MasatoshiKuroda، نويسنده , , SiuLunFok، نويسنده , , BarryJ.Marsden، نويسنده , , S.OlutundeOyadiji، نويسنده ,
Issue Information
روزنامه با شماره پیاپی سال 2005
Pages
17
From page
557
To page
573
Abstract
Inthepresentstudy,staticanddynamicanalyseshavebeenperformedforgraphitemoderatorbrickswithandwithoutkeygroovesunderthedifferentinitialloadingconditionsofpurebendingandslotrotationbyusingthefiniteelementmethod.Thepossibilitiesoftheoccurrenceofmultiplecrackingduetointernalstresseshavebeeninvestigatedintermsofthe(1)initialloadingcondition;(2)vibrationmodeshapes;and(3)dampingofthebricks.Firstly,modaldynamicanalysishasbeencarriedout,andtheeffectoftheinitialloadingconditions,suchaspurebendingandslotrotation,onthedynamicstressresponseswasinvestigated.Itwasfoundthatstressenhancementwasmoresignificantundertheconditionofpurebendingthanthatofslotrotation.Forpurebending,thekeygroovewhichwasoppositetotheprimarycrackingsitehadthemaximumdynamiccircumferentialstress.Thisimpliedthatsecondarycrackingmightoccuratthispositionunderpurebending.Secondly,inordertoinvestigatethedominantmodeshapeforthestressenhancement,naturalfrequencyanalysishasbeenconducted.FastFourierTransformation(FFT)hasalsobeenperformedtoconverttime–domainstressresponsesintofrequency–domainstressresponses.Theinitialloadingconditionsdeterminedwhichmodeshapewasdominantforthestressenhancement.Itwasalsosuggestedthatafundamentalmodeshapeprincipallycontributedtotheoccurrenceofthemultiplecracking.Thirdly,modaldampinganalysishasbeenperformed,andtheeffectofdampingonthestressenhancementwasstudied.Itwasfoundthatdampinghadlittleeffectontheinitialpeakofthedynamicstressresponse.Thissuggestedthatsecondarycrackingmightstilloccuratthekeygrooveoppositetheprimarycrackingsite,evenifdampingwaspresent.Theresultsoftheanalysisgiveafundamentalinsightintothemechanismthatmayleadtomultiplecrackingingraphitecomponentssubjecttointernalstresses.However,theeffectsof3-D,crackpropagationspeedandexternalrestrainthavenotbeentakenintoconsiderationinthepresentstudy.Theseeffectsmaymitigatethepossibilityofsecondarycracking,andarepartsoffurtherinvestigation.
Journal title
Nuclear Engineering and Design Eslah
Serial Year
2005
Journal title
Nuclear Engineering and Design Eslah
Record number
894870
Link To Document