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1、微穿孔板結(jié)構(gòu)吸聲性能的提升效果，復(fù)合共鳴器的機械阻抗板只需要很小的空間距離就能有效吸收低頻聲能量，選擇三角孔微穿孔板和復(fù)合共鳴器的機械阻抗板來提高微穿孔板結(jié)構(gòu)的吸聲性能，在技術(shù)上有進步意義，更具有實際應(yīng)用價值。關(guān)鍵詞：噪聲控制，微穿孔板，機械阻抗，聲阻抗，赫姆霍茲共鳴器，阻抗轉(zhuǎn)移Ⅱ江蘇大學(xué)碩士學(xué)位論文ABSTRACTThetraditionalmicro—perforatedpanelfMVa)absorberiscomposedofmicro-poreandcavity,andreducesnoisebycavityresonance．Relativeresistanceofthew
2、holestructureCallbecontrolledbytheacousticresistanceofmicro-pore，andthereisnoneedtofillanysound—absorbingmaterialinthebackcavity．Itsimplifiessound-absorbingstructure，andavoidssecondarypollutiontotheenvironment．Asaconsequence，itissuitableforhighcleanlinessandhighsoundintensityrequirements．Inthisp
3、aper,howtoimprovethesoundabsorptionperformanceofMPPstructureWaSstudied．TriangleporeMPPwasusedtoimprovesoundabsorptionofMPPinmedium-highfrequency．ThetriangleporeMPPisanewstructureofMPETheacousticimpedanceoftriangleporeMPPwasmeasuredbytest．Then,thesoundabsorptioncharacteristicsoftriangle—poreMPPwe
4、reanalyzedandcomparedwiththetraditionalMPPwiththesameperforationrate．Absorptioncoefficientofdouble—layertriangleporeMPPwascalculatedbymeasuredacousticimpedance，andtheresultwascomparedwiththatoftestanddouble—layerroundporeMPP．Thepromotionmechanismofsoundabsorptionperformancewasanalyzed．Mechanical
5、impedanceunitwasintroducedintotraditionalMPPstructuretoabsorbnoiseinlowfrequency．ThenewcombinedstructureiscomposedofMIPandMPEEachsoundabsorptionunitofthecombinedstructurewasanalyzed．Theabsorptionformulaoftheproposedcombinedstructurewasderivedbyimpedancetransfermethod．Thedampingandstiffnesscoeffi
6、cientsoftheMIPweredeterminedbythehalf-powerbandwidthmethod．Thesoundabsorptioncoefficientcurveofthecompositestructurewasmeasuredbystandingwavetubeexperimentandtheresultswerecomparedwiththecalculativesoundabsorptioncoefficient．HRwasintroducedtoabsorbnoiseinlowfrequency．HRisfixedontheMIPtocompensat
7、ethesoundabsorptionperformancebetweenmechanicalimpedanceresonanceandMPPresonance．Theabsorptionformulaoftheproposedcombinedstructurewasderivedbyimpedancetransfermethod，andcorrespondingtestsweredonetoverifytheabsorptionformula
