基于動力測試的鋼筋混凝土簡支梁損傷識別方法研究.pdf

1、北京工業(yè)大學碩士學位論文基于動力測試的鋼筋混凝土簡支梁損傷識別方法研究姓名：秦棟濤申請學位級別：碩士專業(yè)：防災減災工程及防護工程指導教師：閆維明20080501北京T業(yè)大學丁學碩十學位論文AbstractTramcisasocialeconomicbloodandabridgeisatrafficthroatThedevelopmentofsocialeconomywillbelimitedifthetrafficdoesntmovet

2、oand療。地SOitisveryimportanttomakesureeverybridge’SfunctionandsafetyTouseeverybridgenormallyasdemandstotestormonitortobridges’safetyfromnowandthenAtpresentthereisalargequantityofbridgesinourcountl拶Onehand，manyoldbridgeshav

3、eapproachedtheirdesignlifetime，theircomponentshaveagedandbedamagedOntheotherhand，anumberofnewandlargescalebridgeswillbebuiltToassurethesebridgessafetyandavoidaccidents，weshouldgetonmonitoronlinetonewbridges，anddetectdama

4、geandidentifyreliabilitytooldbridgesConsideredthefeaturethatnaturalfrequenciesofastructureareeasytomeasurewithrelativehi【ghaccuracythusdamagedetectionmechanismbyfrequencymeasuFementisanalyzedandvalidatedThreekindsofdamag

5、edetectionmethodsarecomparedinthispaperandthenafairlygoodstructuredamagedetectionmethodbyStubbsisimprovedbytheauthorThecalculationofimprovedmethodissimplifiedwithaclearconceptAndmatrixAcanbesavedasanaturalinformationafte

6、rinitialcomputationfordamagedetectionthatfollowsAnalysisresultsshowthatfrequenciescanbeusedaloneforstructuraldamagedetection謝maccuracyandsignificanceinacertainextentwithminimumcostofresourcesBecauseofitssimplicityincompu

7、tationclearnessinconceptsandstrongpracticalitythismethodisconvenienttoengineeringapplicationAsimplesupportedbeamcanbetreatedasasinglemodesystemSRR(stiffnessreductionrate)ofthebeamisintroducedtodenotebridgedamageextentand

8、itspracticalityisverifiedbybeamtestCracksoftenexistinreinforcedconcretebridgesThereismoreorlessnonlinearvibrationbeforetheoccurrenceofcracksOncecracksappearedonbridges，therewillbeobviousnonlinearvibrationarousedbyeffecto

9、fbreathingcrackThevibrationl囂ponseofthebeamarousedbyeffectofbreathingcrackismodeledbyusingnonlineardementsinfiniteelementmodelTherelationshipbetweencrackheightandmodalfrequencyisanalyzedandsummarizedaftercracksappearingi