基于多通道空气耦合的桥面浅层缺陷检测研究

Research on detection of bridge panel shallow defects based on multi-channel air coupled method

提出一种基于多通道空气耦合的桥面板浅层缺陷快速检测方法,并开发一套多通道桥面浅层缺陷快速检测系统,该系统由多通道冲击源、MEMS声学传感器、距离编码轮、数据采集和信号处理系统组成,可用于快速检测混凝土桥面板内的浅层缺陷,首先通过数值模拟方法分析了浅层缺陷在瞬态激励下的响应特性,进而开展现场试验研究,对球链激励下混凝土桥面板内浅层分层等缺陷的声信号进行短时傅立叶变换处理,综合声信号、距离和时间信息得到了桥面板内部的损伤情况,并绘制了损伤二维图像,检测结果还与回弹法和超声脉冲波速法检测结果进行了对比验证.通过现场测试证明该测试方法具有高效、高灵敏度和可重复等优点,对于桥面板浅层分层缺陷有很好的应用前景.

In this paper,a rapid detection method of shallow defects in Bridge Deck Based on multi-channel air coupling is proposed,and a set of multi-channel rapid detection system for shallow defects in bridge deck is developed,which can be used for rapid detection of shallow defects in concrete bridge deck.The system consists of multi-channel shock source,MEMS acoustic sensor,distance encoder,data acquisition and signal processing system.Firstly,the response characteristics of shallow defects under transient excitation are analyzed by numerical simulation method,and then the field test is carried out.The acoustic signal of shallow delamination and other defects in concrete bridge deck under ball chain excitation is processed by short-time Fourier transform.The damage of bridge deck on the detection path is obtained by synthesizing the acoustic signal,distance and time information,and the two-dimensional image of damage is drawn.The test results are compared with those of rebound method and ultrasonic pulse wave velocity method.The field test shows that this method has many advantages such as high efficiency,high sensitivity and repeatability,and has a good application prospect for the shallow delamination defects of bridge deck.