铁路混凝土箱梁箱内空腔共鸣噪声及其影响研究

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1、第37卷第7期’铁道学报Vo1．37No．72015年7月JOURNALOFTHECHINARAILWAYSOCIETYJuly2015文章编号：1001—8361(2015)07—0107—05铁路混凝土箱梁箱内空腔共鸣噪声及其影响研究张迅，王党雄，李小珍(西南交通大学土木工程学院，四川1成都610031)摘要：为探讨铁路混凝土箱梁箱内空腔共鸣噪声及其影响，以某客运专线32rfl预应力混凝土简支箱梁为研究对象，开展实桥振动与噪声试验，分析箱梁振动与噪声的时域特性及频谱特性。采用有限元法建立三维空腔声模型，

2、分析箱内空腔声模态与腔内噪声峰值的关联性。采用边界元法分别建立两端封闭与两端开口的箱梁声学模型，验证箱内空腔共鸣噪声的来源及其影响。结果表明：在特定行车速度下，箱内噪声出现“拍”现象，显著增大箱内噪声，瞬时最大声压可达4OPa，峰值频率为75．0Hz；箱内噪声的“拍”现象来源于顶板的振动噪声，顶板的振动峰值频率与箱内空腔垂向声模态频率吻合时，箱内噪声显著增大；由于梁缝的声泄漏特性，箱内空腔共鸣噪声在梁缝处衰减较大，但其对桥梁两侧总体噪声的影响不可忽略。关键词：混凝土箱梁；结构噪声；空腔声模态；空腔共鸣；边界

3、元法中图分类号：U24：TBI23文献标志码：Adoi：10．3969／J．issn．1001—8361．2015．07．017StudyonCavityResonanceNoiseofRailwayConcreteB0X-GirderandItsInfluenceZHANGXun，WANGDang—xiong。LIXiao—zhen(SchoolofCivilEngineering，SouthwestJiaotongUniversityChengdu610031，China)Abstract：Inorde

4、rtostudythecavityresonancenoiseofconcretebox-girderanditsinfluence，afieldtestcon—cerningvibrationandnoiseofa32mPCsimply—supportedbox-girderwascarriedout，toinvestigatethetime-domaincharacteristicsandfrequencyspectrumcharacteristicsofvibrationandnoiseofthebo

5、x-girder．A3DcavityacousticalmodelwasestablishedbasedonFEMtoanalyzethecorrelationbetweencavityacousticmodeandcavitynoisepeak．Twoacoustica1modelsforbox-girderswithclosedendsandopenends，werebuiltbasedonBEM，respectively，toverifythesourceandinfluenceofcavityres

6、onancenoise．Resultsshowedthatthe“beat”wavephenomenonofcavitynoiseappearedunderaspecifictrainspeed，significantlyincreasingthecavi—tynoise，withthetransientmaximumsoundpressureofcavitynoisereaching40Paandthenoisepeakfrequen—cybeing75．0Hz；The“beat”wavephenomen

7、onofcavitynoisederivedfromthevibrationofdeck．Whenthepeakvibrationfrequencyofdeckmatchedwiththefrequencyofverticalacousticmodalofthecavity，thecavitynoisesignificantlyincreased．Thecavityresonancenoiseattenuatedtoalargeextentattheexpansionjointsdueto“acoustic

8、leakage”．However，theinfluenceofcavityresonancenoiseontheoveral1noiseoftwosidesofbridgecannotbeneglected．Keywords：concretebox-girder；structure—radiatednoise；cavityacousticmode；cavityresonance；BEM混凝土箱梁在轮轨不平顺激励下