简介:TheDonnelltheoryofshellisappliedtodescribeshellmotionandlayermotionisdescribedbymeansofthree-dimensionalNavierequations.Usingdeformationharmoniousconditionsoftheinterface,theeffectsofstiffenersandlayeraretreatedasreverseforcesandmomentsactingonthecylindricalshell.Instudyingtheacousticfieldproducedbyvibrationofthesubmergedring-stiffenedcylindricalcoatedshell,thestructuredynamicequation,Helmholtzequationinthefluidfieldandthecontinuousconditionsofthefluid-structureinterfacecomposethecou-plingvibrationequationofthesound-fluid-structure.Theextractofsoundpressurecomesdowntotheextractofcouplingvibrationequation.Byuseofthesolutionoftheequation,theinfluencesofhydrostaticpressure,physicalcharactersandgeometricparametersofthelayeronsoundradiationarediscussed.
简介:Afiniteelement/boundaryelement—modifiedmodaldecompositionmethod(FBMMD)ispresentedforpredictingthevibrationandsoundradiationfromsubmergedshellofrevolution.Im-provementhasbeenmadetoacceleratetheconvergencetoFBMDmethodbymeansofintroducingtheresidualmodeswhichtakeintoaccountthequasi-statecontributionofallneglectedmodes.Asanexample,thevibrationandsoundradiationofasubmergedsphericalshellexcitedbyaxisymmetricforcearestudiedincasesofka=1,2,3and4.FromthecalculatedresultsweseethattheFBMMDmethodshowsasignificantimprovementtotheaccuracyofsurfacesoundpressure,normaldisplace-mentanddirectivitypatternsofradiatingsound,especiallytothedirectivitypatterns.
简介:<正>AttheinvitationoftheKazankaiFoundationofJapan,AsiaNewZealandFoundationandAustralianInstituteofInternationalAffairs,aCAFIUdelegationheadedbyAiPing,MemberoftheNationalCommitteeoftheCPPCC,formerVice-MinisterofIDCPCandCAFIUVice-President,
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