冲击荷载下基于动力宏应变的组合梁损伤识别方法研究

打开文本图片集

中图分类号：U448.21 文献标识码：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

由于车辆超载、环境恶化和疲劳反复加载等原因，钢-混凝土组合梁在服役过程中会出现混凝土板开裂、钢梁构件锈蚀断裂及剪力连接件失效等损伤，不仅影响桥梁的外观和正常使用，严重时还会影响结构的承载力和使用寿命，应进行及时准确的损伤识别及性能维护。（剩余12224字）