现役钢-混凝土组合结构界面损伤超声导波无基线识别及评价

项目名称： 现役钢-混凝土组合结构界面损伤超声导波无基线识别及评价

项目编号： No.51478079

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： 李冬生

作者单位： 大连理工大学

项目金额： 90万元

中文摘要： 界面损伤是钢-混凝土组合结构最严重的破坏形式，它具有隐蔽性比较高、随机性强、局部化突出等特征，超声导波技术非常适合界面损伤监测，但是现有的超声导波大部分都依赖健康状态下的基线信号去识别结构损伤，很难真正用于现役工程。本项目提出无基线超声导波监测技术识别钢-混凝土界面损伤并进行评价。首先提出一种计算速度快、精度高的小波谱单元模拟钢-混凝土界面损伤波导传播。然后，建立钢-混凝土界面损伤超声导波无基线监测数学模型、提出基于实验方法实时获取结构频散曲线。其次，针对试验中导波信号频散、多模态、非线性等特点，发展频散补偿和移除方法、多模态分离技术。再次，在上述处理后的超声导波信号基础上，运用数据驱动技术提取损伤特征信号，构建特征数据库，自动识别界面损伤；并发展界面不同损伤类型超声导波成像方法、界面早期损伤非线性超声导波监测。最后，通过试验验证本项目提出的方法有效性和正确性。

中文关键词： 超声导波；界面损伤；无基线损伤识别；信号处理；健康监测

英文摘要： Interface damage is the most serious damage type in reinforcd concrete composite structures. It has some obvious characteristics, for example,high hiding,strong random,clear localization.Ultrasonic guided wave(UGW) techniques are very suitable for the interface damage monitoring, however,conventional UGW methods compare signals obtained from the pristine condition of a structure (baseline signals) with those from the current state, and relate certain changes in the signal characteristics to damage.In this project the baseline-free interface damage dectection methods were proposed.First,corresponding numerical models based on rapid speed and high precision wavelet spectral element method were developed. Second,a fully automated baseline-free technique for interface damage detection in reniforced concrete was established,developing signal processing techniques to experimentally estimate dispersion curves in-situ. Third, due to the wave propagation environment being dispersive, multi-modal, and multi-path,a compensate and cancellation method and of dispersion ,multi-mode separation techniques were proposed. A data-driven framework for effective and robust analysis of guided wave signals is devised to automatically detect and localize interface damage.The sensed ultrasonic data were characterized and mapped onto a high dimensional feature space.Different wavefield images were processed to detect defects in reinforced concrete interface, and a nonlinear guided wave technique was applied to monitor interface early damage.Finally, the effectiveness and correctness of these methods in the project would be verified through experiment.

英文关键词： ultrasonic guided wave;interface damage;baseline-free damage detection;signal processing;health monitoring