桥梁缆索声发射监测数值模拟与试验研究

项目名称： 桥梁缆索声发射监测数值模拟与试验研究

项目编号： No.51478347

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 建筑科学

项目作者： 孙利民

作者单位： 同济大学

项目金额： 90万元

中文摘要： 拉索损伤是缆索承重体系桥梁的典型病害之一。为了将声发射技术运用于桥梁缆索健康监测中，本课题拟研究声发射信号在桥梁缆索中的传播特性这一关键问题。首先，以声发射信号在单根钢丝中的传播为对象，以解析解验证有限元模拟方法，以此为基础建立声发射信号在多根钢丝中传播的精细化有限元模型；研究声发射信号的解耦方法，提出实用的波形特征分析方法；通过可以精准定量激励源的激光超声试验，验证声发射在桥梁缆索中传播的有限元模拟方法的准确性，并研究相关参数的影响；最后根据声发射信号在多根钢丝中传播的有限元模拟和激光超声试验结果，建立声发射信号在整根拉索中的传播模型。本课题的研究成果将为桥梁缆索声发射监测技术奠定理论基础，具有明确的工程应用价值。

中文关键词： 声发射；桥梁缆索；传播特性；健康监测；激光超声

英文摘要： Cable damage is one of the typical diseases of cable supported bridges. In order to apply acoustic emission(AE) technique to the health monitoring of bridge cables, this research intends to study the propagation characteristics of AE signals in bridge cables, which is a key problem for this technique. First, the propagation characteristics of AE signals in a steel wire will be simulated by finite element method and the results will be compared with those calculated by the elastic wave propagation theory to confirm the finite element model. Based on the single wire model, a refined finite element model will be established to simulate AE signals propagating in a multi-wire cable. Second, a decoupling method for AE signals will be studied and a useful method for analysing waveform characteristics will be established. Third, a laser ponit source, which can be quantified accurately, will be used to analyse AE signals propagating in bridge cables. The experimental results is helpful to confirm the finite element analysis. Finally, based on the finite element simulation and laser ultrasonic experimental results of AE signals propagating in a multi-wire cable, the theoretical model of AE signals propagating in a real bridge cable will be established.The results of this study, with a promising engineering value, will lay a solid theoretical foundation for applying AE technique to the health monitoring of bridge cables.

英文关键词： acoustic emission;bridge cables;propagation characteristics;structural health monitoring;laser ultrasonics