沖擊荷載下基于動力宏應(yīng)變的組合梁損傷識別方法研究

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中圖分類號：U448.21 文獻標識碼：A DOI：10.7535/hbkd.2025yx04011

Research on damage identification method of composite beams based on dynamic macro-strain under impact load

LI Yunsheng 1，2 ，HEDing 1，2 ，JIA Xiaoyuan1，CUI Chunlei3，Rong Xueliang 1，2 ，ZHANG Yanling 1，2

（1．School of Civil Engineering，Shijiazhuang Tiedao University，Shijiazhuang，Hebei O5o043，China; 2.Key Laboratory of the Ministry of Education for Road and Railway Engineering Safety Assurance， Shijiazhuang Tiedao University，Shijiazhuang，Hebei O5oO43，China； 1RoadandBridgeTechnology CompanyLimitedofChina Communications Construction，Shijiazhuang，Hebei O50ooo，China）

Abstract：Inorder toachievedamage identificationof steel-concretecompositebeamsbasedondistributed long-gauge fiber bragggrating（FBG）sensors，modeltestsandfiniteelementanalysisofcomposite beams underimpactloads wereconducted.

The damage assessment index βn constructed from the dynamic macro-strain spectral amplitude was used to identify damage of stelgirder section and stud connections，respectively.Theresearch results show that when long-gauge FBG sensorsare continuouslyarangedalong thelongitudinaldirectiononthebotomsurfaceof steel girder，themacro-strainofthesensors in the damaged area increases significantly. When the evaluation index βn>0 ，it can be determined that cross-sectional damage has occurred withintherangeofthesensor，andthisindexis more sensitivetothecrack heightonthe webofthe steel girder thantheexpansion width onthe bottom flange.Forstud damage，long-gaugesensorscanbe arrangedin pairs symmetricall on boththeupperandlowersurfacesof theinterface inconcreteslabandstelgirder，andthe measured macro-straintimehistory can be subtracted to obtain the slip macro-strain time history. Then，based on the evaluation index βn obtained from the amplitudeoftheslipmacro-strainspectrum，andusingthetwo-stagidentificationmethod，thelocationofdamagedstudcanbe identfiedeffectively.Overall，easonablearangementoftedistributedlonggaugesensorscanrealizedamageidentificationof differentcomponents instel-concretecompositebeams，especiallytheconnectors whichareconcealed in theconcrete slab.

Keywords：composite structure；stel-concrete composite beam；damage identification；dynamic macro-strain；fiber bragg grating sensors;impact load

由于車輛超載、環(huán)境惡化和疲勞反復(fù)加載等原因，鋼-混凝土組合梁在服役過程中會出現(xiàn)混凝土板開裂、鋼梁構(gòu)件銹蝕斷裂及剪力連接件失效等損傷，不僅影響橋梁的外觀和正常使用，嚴重時還會影響結(jié)構(gòu)的承載力和使用壽命，應(yīng)進行及時準確的損傷識別及性能維護。（剩余12224字）