資源描述:
《Theory of Propagation of Elastic Waves in a Fluid-Saturated Porous Solid. I. Low-Frequency Range》由會員上傳分享,免費在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、THEJOURNALOFTHEACOUSTICALSOCIETYOFAMERICAVOLUME28.NUMBER2MARCH.1956TheoryofPropagationofElasticV?ravesinaFluid-SaturatedPorousSolid.I.Low-FrequencyRangeM.A.B?OT*ShellDevelopmentCompany,RCAB1dlding,NewYork,NewYork(ReceivedSeptember1,1955)Atheoryisdevelopedforthepropagationofstresswavesin
2、aporouselasticsolidcontainingacompressibleviscousfluid.Theemphasisofthepresenttreatmentisonmaterialswherefluidandsolidareofcomparabledensitiesasforinstanceinthecaseofwater-saturatedrock.ThepaperdenotedhereasPartIisrestrictedtothelowerfrequencyrangewheretheassumptionofPoiseuilleflowisval
3、id.TheextensiontothehigherfrequencieswillbetreatedinPartII.Itisfoundthatthematerialmaybedescribedbyfournondimen-sionalparametersandacharacteristicfrequency.Therearetwodilatationalwavesandonerotationalwave.Thephysicalinterpretationoftheresultisclarifiedbytreatingfirstthecasewherethefluid
4、isfrictionless.Thecaseofamaterialcontainingaviscousfluidisthendevelopedanddiscussednumerically.Phasevelocitydispersioncurvesandattenuationcoefficientsforthethreetypesofwavesareplottedasafunctionofthefrequencyforvariouscombinationsofthecharacteristicparameters.1.INTRODUCTIONThisisobtaine
5、difa"dynamiccompatibility"relationisverifiedbetweentheelasticanddynamicconstants.ThisURofelasticpurposewavesistoinestablishasystematheorycomposedofpropagationofaporousisacasewheredissipationduetofluidfrictionwillelasticsolidsaturatedbyaviscousfluid.Itisassumeddisappear.InSec.6thedynamic
6、relationsarederivedthatthefluidiscompressibleandmayflowrelativetowiththeadditionoffluidviscosityandSec.7derivesthesolidcausingfrictiontoarise.PartIwhichisthepropertiesofthepropagationofthewaveswhenpresentedhereassumesthattherelativemotionofthedissipationispresent.Itisfoundthatthephaseve
7、locityfluidintheporesisofthePoiseuilletype.AsalreadyofrotationalwavesincreasesslightlywiththefrequencypointedoutbyKirchhoffthisisvalidonlybelowafwhiletheabsorptioncoefficientisproportionaltothecertainfrequencywhichwedenotebyf?,andwhichsquareofthefrequency.Allplotsarepresentedno