柔度差曲率,损伤识别

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1、第26卷第2期Vol.26No.2工程力学2009年2月Feb.2009ENGINEERINGMECHANICS188文章编号：1000-4750(2009)02-0188-08基于柔度差曲率矩阵的结构损伤识别方法*1,21,31李永梅，周锡元，高向宇(1.北京工业大学建筑工程学院，北京100124；2.北京工业大学城市与工程安全减灾省部共建教育部重点实验室，北京100124；3.工程抗震与结构诊治北京市重点实验室，北京100124)摘要：柔度是较频率和位移模态更敏感的结构损伤标示量。提出利用结构损伤前、后的柔度矩阵，先后对柔度矩阵差的列、行进行两次差

2、分，求得柔度差曲率矩阵(δFlexibilityCurvatureMatrix)，并以其对角元素作为检测结构损伤指标(δFCMD)的新方法。该方法仅需低阶模态参数即可进行损伤检测，不论对简支梁、悬臂梁、固支梁，或多跨连续梁，单一位置损伤、支撑处损伤、轻微损伤，还是多种损伤共存，均具有损伤定位的能力、并能定性反映损伤程度。通过与已有的柔度差、柔度变化率、均匀荷载面曲率差等柔度指标的数值模拟分析研究，显示了该指标检测损伤的有效性和优越性。关键词：结构；损伤识别；柔度；曲率；柔度差曲率矩阵中图分类号：O327;TU311.3;TB123文献标识码：ADETE

3、CTIONINDICTOROFSTRUCTURALNONDESTRUCTIVEDAMAGEBASEDONCURVATURE-FLEXIBILITY-DIFFERENCEMATRIX*1,21,31LIYong-mei,ZHOUXi-yuan,GAOXiang-yu(1.CollegeofCivilEngineeringandArchitecture,BeijingUniversityofTechnology,Beijing100124,China;2.KeyLaboratoryofUrbanSecurityandDisasterEngineeringo

4、fMinistryofEducationofChina,BeijingUniversityofTechnology,Beijing100124,China;3.BeijingKeyLaboratoryofEarthquakeEngineeringStructuralRetrofit,Beijing100124,China)Abstract:Forstructuraldamage,theflexibilityismoresensitivethanitsfrequencyormode.Thecurvaturedifferencematrixinflexib

5、ilityispresentedasanewindexofnondestructivedamagedetection,derivedfromthechangeinstructuralflexibilitiescalculatedbeforedamagingandafterdamagingbymeansofdifferencecalculationtwice,firstlytocolumns,andthentorows.ThereforeanewindicatorcalledδFlexibilityCurvatureMatrixDiagonal(δFCM

6、D)isconstructedthroughprincipaldiagonalelementsbasedonthecurvaturedifferencematrixinflexibility.Numericalsimulationexamplesindicatethatthedamagelocationandseverityinstructures,withsingledamage,multipleones,lighteronesandonesatthesupports,canbedetectedefficientlyforcantileverbeam

7、s,fixedsupportedbeams,simplysupportedbeams,continuousbeamsandsoonbyδFCMDthroughonlyafewofthelowerordermodes.ComparedtotheaforementionedflexibilityindicatorsandδFCMD,suchasthechangeinflexibility,therateinflexibility,thecurvaturechangeinuniformloadsurface(ULSC),theeffectivenessand

8、advantageofδFCMD,etcareshown.Keywords:structure