基于小波變換的橋梁模態(tài)識(shí)別方法研究.pdf

1、同濟(jì)大學(xué)土木工程學(xué)院碩士學(xué)位論文基于小波變換的橋梁模態(tài)識(shí)別方法研究姓名：侯偉申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：橋梁與隧道工程指導(dǎo)教師：孫利民孫智20070601AbstractABSTRACTTheBridgeisoneofthemostimportantfactorsforthenationaleconomyThebridgeiscommonlyattraffichinge，soitisveryimportanttoinsurethestruc

2、ture’ssecurityandreliabilityRecentlymoreandmorepeopleattachimportancetesearchandpracticeofthebridgehealthmonitoringThemostimportancethingsforthebridgehealthmonitoringisobtainingthebridgehealthindex，whichcandistinguishdes

3、troyedbridgestructuresfromgoodonesTheresearchandpracticeprovethewavelettransformisanefficientmethodtoobtainthatindexThewavelettransformisatime—frequencyandtime—scaleanalysisonsignalsIthasmanyexcellentcharacteristic，soiti

4、ssweepingappliedinpracticalengineeringThewavelettransformisinductedintomodalidentificationinthepaperandthereissomeimprovementonidentifyingclosemodals，wipingoffthestimulatecharactersinsignalsandend—effectsThefollowingaret

5、hemaintasksconductedinthepaper：firstlythetheoryofthewavelettransformisparticularexplained，basedonthewavelettransforminmodalidentification，andit’smeritsinmodalidentificationarealsoexplained；secondlytherearesomeexamplesbas

6、edonthewavelettransformOneofthemisthethreefreedomsspring—masssystem，whichisusedtoprovethatthewavelettransformisviabletoidentifyclosemodals；anotheroneisthecable—stayedbridge，whichisusedtoprovethatthewavelettransformisviab

7、letoidentifycomplexstructure’smodalsAndthereareexperimentstoprovethatthewavelettransformisviabletoidentifystructure’smedalsunderimpulseexcitationFinallytherearesomefieldexperimentstoprovethatthewavelettransformisviableto

8、identifystructure’smodalsinambientvibrationTheresearchresultsintheorylabandfieldexperimentsverifiedtheaccuracyofthewavelettransformbasedmodalidentificationalgorithmKeyWords：bridge，healthmonitoring，modalidentification，wav