混凝土结构中分布式电脉冲时域反射损伤诊断技术研究

A distributed sensing system based on time-domain reflectometry is proposed for health monitoring of concrete structures, which uses the embedded electromagnetic transmission line and relflected electromagnetic pulse caused by local damage to make localization and evaluation. Affects of the flaw and damage on the electrical parameters of concrete, such as permittivity or conductivity were investigated. Variations of the reflected pulse with the location, type and extent of the damages were studied by experiments and numerical simulation. A wavelet modeling approach was proposed to extract damage information from the reflected pulse. The proposed technique is proved to be able to detect chloride intrusion, corrosion of rebars, void and crack in the structure. It is especially useful for dignosis of the hidden part in the structure that is not detectable by conventional methods.

利用电磁传输线结构的脉冲时域反射原理，构成混凝土结构中的分布式传感系统，监测材料和结构内部的缺陷、损伤和应变状况。研究上述状况引起传输介质的介电常数、电导率等电参数的变化规律，通过实验和计算确定缺陷和损伤的位置、类型和程度对反射脉冲的影响，采取信号处理手段提取信号特征并加以识别，提高对结构内部的在线监测和损伤定位能力。