压电陶瓷传感器监测混凝土内部缺陷的可行性研究

Feasibility Study on Internal Defect Monitoring of Concrete Structure Based on Piezoceramics Transducer

为监测在役混凝土结构在使用过程中的内部缺陷程度变化并定位缺陷位置,本文探索一种基于应力波的探测方法并进行试验研究,将压电传感器(PZT)以阵列形式安装在混凝土表面,将混凝土划分为不同区域,阵列中的一个传感器发射波,另一个传感器接收波,采用扫频模式和五峰值脉冲模式对混凝土不同区域进行监测。试验结果表明,当应力波通过待监测区域时,由于混凝土内部存在缺陷,应力波幅值衰减,波能降低。为了量化混凝土结构内部缺陷程度,构造基于接收信号的能量指数和损伤指数,并分别建立其与缺陷程度的函数关系,依据不同区域能量指数和损伤指数差异,确定混凝土内部缺陷存在的区域。试验结果与试件实际情况相吻合,验证了本文采用压电传感器监测混凝土内部缺陷的可行性。

To monitor the change of the internal defect degree and locate the defect position of the concrete structure in service,this paper explored a detection method based on stress waves and carries out experimental research.Piezoceramics transducer(PZT)was installed on the concrete surface in the form of an array,and the concrete was divided into different areas.One sensor in the array emitted waves and the other received waves,and sweep frequency mode and five peak pulse modes were used to monitor different areas of concrete.The test results show that when the stress waves pass through the area to be monitored,due to the existence of internal defects in the concrete,the amplitude value of the stress waves attenuates and the wave energy decreases.In order to quantify the degree of internal defects in concrete structures,the energy index and damage index based on the received signal are constructed and their functional relationships with the degree of defects are established,respectively.According to the difference between the energy index and damage index in different areas,the areas where internal defects exist in concrete are determined.The test results are consistent with the actual situation of the test pieces,which verifies the feasibility of using piezoelectric sensors to monitor the internal defects of concrete in this paper.