摘要
为准确识别双块式无砟轨道轨枕与道床板连接面脱空损伤,建立了双块式无砟轨道冲击回波有限元模型,分析界面损伤对弹性波传播规律的影响。在室内浇筑含有不同损伤位置和不同损伤程度的混凝土复合试件,采用冲击回波法进行损伤识别。研究结果表明:脱空损伤会显著影响弹性波在界面处的传播,基于回波信号分析可识别损伤;弹性波频率主要受激振锤大小的影响,应结合结构易损位置和理论计算选取合适的激振锤;混凝土复合试件的试验厚度值与理论厚度值相差仅为1 cm,测试结果合理,可用于判断脱空损伤程度,但不能确定损伤区域;利用平面成像技术可准确识别轨枕与道床板界面脱空范围,为双块式无砟轨道结构养护维修提供一定参考,试验结果验证了冲击回波法用于双块式轨道层间脱空识别的可行性和合理性。
To identify the contact loss of the interface between sleeper and track slab for twin-block slab track accurately,a finite element model of impact echo for twin-block slab track is firstly established to analyze the influence of interface damage on the propagation law of elastic waves.And concrete composite specimens with different damage positions and degrees are poured indoors,and the damage identification is carried out by using im‑pact echo method.The results show that contact loss can significantly affect the elastic wave propagation at the interface,and the damage can be identified based on the analysis of the echo signals.The elastic wave frequency is mainly affected by the size of the excitation hammer,and the appropriate hammer should be selected according to the vulnerable structure position and theoretical calculations.The difference between the experimental thickness and the theoretical thickness of the concrete composite specimen is only 1 cm,which means the test results are reasonable.And it can be used to judge the degree of contact loss,but the damage area cannot be determined.The plane imaging technology can accurately identify the range of interface contact loss between the sleeper and the track slab,which provides a certain reference for the maintenance and repair of the twin-block 198 slab track structures.The test results verify the feasibility and rationality of the impact echo method used in the identification of interlayer contact loss for the twin-block tracks.
作者
许雪山
杜威
任娟娟
杜俊宏
罗磊
XU Xueshan;DU Wei;REN Juanjuan;DU Junhong;LUO Lei(Key Laboratory of High-Speed Railway Engineering,Ministry of Education,Southwest Jiaotong University Chengdu,610031,China;School of Civil Engineering,Southwest Jiaotong University Chengdu,610031,China)
出处
《振动．测试与诊断》
EI
CSCD
北大核心
2024年第1期81-87,198,199,共9页
Journal of Vibration,Measurement & Diagnosis
基金
国家重点研发计划资助项目(2021YFF0502100)
国家自然科学基金资助项目(52278461,52308467)
高速铁路无砟轨道设计与维护四川省青年科技创新研究团队资助项目(2022JDTD0015)。
关键词
双块式无砟轨道
脱空识别
冲击回波法
模型试验
平面成像
twin-block slab track
contact loss identification
impact echo method
model test
plane imaging
