简介:Thebehaviorofthestressintensityfactoratthetipsofcrackssubjectedtouniaxialtensionσχ^∞=pwithtraction-freeboundaryconditioninhalf-planeelasticityisinvestigated.Theproblemisformulatedintosingularintegralequationswiththedistributiondislocationfunctionasunknown.Intheformulation,wemakeusedofamodifiedcomplexpotential.Basedontheappropriatequadratureformulastogetherwithasuitablechoiceofcollocationpoints,thesingularintegralequationsarereducedtoasystemoflinearequationsfortheunknowncoefficients.Numericalexamplesshowthatthevaluesofthestressintensityfactorareinfluencedbythedistancefromthecrackstotheboundaryofthehalf-planeandtheconfigurationofthecracks.
简介:Themulti-parameterinversescatteringproblemofelasticwaveequationwithsinglefre-quencyisinvestigatedwithinBornapproximation.Byuseofawidebandmeasuringschemeinwhichbothtransmittersandreceiversscanoverthehalf-spacesurface,theformulaofthescatteringfieldofelasticwaveisderived.Fourtypesofmodeconversionofelasticwave(P→P,P→S,S→P,S→S)areseparatedfromthescatteringfield.Thesecomponentscontainsufficientinformationforustorecon-structtheconfigurationsofthedensityandLaméparametersofthemedium.Theinverseformulashavetheformoffilteredback-propagationasintheacousticdiffractiontomography.Computersimu-lationsarealsoobtained.
简介:Inthispaper,weconsiderthenonsymmetricalhalf-planeprediction.Apredictiontheoreticproofofthefundamentalformulaaboutonesteppredictionerrorisgiven.AWold-typedecompositionanditsspectralrepresentationtheoremareproved.Spectralextractionproblemsofthehalf-planeinnova-tionsanditssingularcomponentsareinvestigated.
简介:Inthispaper,thenotionofp-waveletpacketsonthepositivehalf-lineR+isintroduced.Anewmethodforconstructingnon-orthogonalwaveletpacketsrelatedtoWalshfunctionsisdevelopedbysplittingthewaveletsubspacesdirectlyinsteadofusingthelowpassandhigh-passfiltersassociatedwiththemultiresolutionanalysisasusedintheclassicaltheoryofwaveletpackets.Further,themethodovercomesthedifficultyofconstructingnon-orthogonalwaveletpacketsofthedilationfactorp>2.
简介:Thispaperisconcernedwiththelarge-timebehaviorofsolutionstoaninitial-boundary-valueproblemforfullcompressibleNavier-Stokesequationsonthehalfline(0,∞),whichisnamedimpermeablewallproblem.Itisshownthatthe3-rarefactionwaveisstableunderpartiallylargeinitialperturbationiftheadiabaticexponentγiscloseto1.Herepartiallylargeinitialperturbationmeansthattheperturbationofabsolutetemperatureissmall,whiletheperturbationsofspecificvolumeandvelocitycanbelarge.Theproofisgivenbytheelementaryenergymethod.
简介:ALegendrespectralelement/LaguerrecoupledmethodisproposedtonumericallysolvetheellipticHelmholtzproblemonthehalfline.Rigorousanalysisiscarriedouttoestablishtheconvergenceofthemethod.Severalnumericalexamplesareprovidedtoconfirmthetheoreticalresults.TheadvantageofthismethodisdemonstratedbyanumericalcomparisonwiththepureLaguerremethod.
简介:Surfaceeffect,whichisattributedtothedifferentenvironmentsurroundingthesurfaceornear-surfaceatomsfromthatembracingthebulkatoms,maybecomesignificantwhenthesurface-to-volumeratioofabodyislarge.Thispaperconsiderstheeffectofaplaneboundaryofapiezoelectricbodymodeledasathinlayerwithspecifiedmaterialproperties,forwhichatransferrelationbetweenthestatevectorsatthetopandbottomsurfacesisderivedbasedonthestate-spaceformulations.Theequationsofsurf...
简介:Theinversionofstongscattererembeddedinthehalf-spaceisanimportantprobleminengi-neeringandaverydifficultnonlinearprolbeminmathematics,forwhichtheBorniterativemethodisofnoeffect.Inthispaperthemomentmethodisusedinthediscretizationprocedure.Anumericalapproachispr-esentedbyemployingtheregularizationtechniqueandDBI(distortedBorniterative)method.Thesimulationresultsshowthattheapproachpresentedisefficient.