Studies on Mooring Energy Based on Finite Element Method

(整期优先)网络出版时间:2010-04-14
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Tounderstandthemooringenergyduringpositioning,theexpressionsoffouritemsconcerningmooringlineenergyarepresentedbasedonafiniteelementmodel,includinggravitationalandelasticpotentialenergy,kineticenergyanddissipatedenergyduetomooring-induceddamping.Inastaticcase,theforcecalculatedfromthederivativeofpotentialenergywithrespecttodistanceiscomparedwiththatofdirectcalculation.Theresultsarefoundfitwell,whichindicatesthelawofconservationofenergyandalsoshowsthecorrectnessofthepotentialenergyresults.Forthecasesofasinglemooringlinewiththeattachmentpointoscillatingwithdifferentamplitudesinhorizontalorverticaldirection(correspondingtosurgeandrollmotionsrespectively),andthecaseofthemooringlinewithahorizontalbichromaticoscillationontheattachmentpoint,thetimehistoryofthefirstthreeitemsarecalculatedandanalyzed,also,theindicatordiagramformooring-induceddampingaregiven.Theseresultsrevealtheenergystateofthemooringlineandcanprovideabetterunderstandingofhowthemooringlineworks.