基于压电陶瓷的PVA-ECC混凝土柱裂缝损伤监测

Crack Damage Monitoring of PVA-ECC Columns Based on Piezoelectric Transducer

目的基于压电陶瓷传感器对聚乙烯醇纤维增强水泥基复合材料(PVA-ECC)进行裂缝损伤识别研究,以指导实际工程.方法在实验室浇筑7个PVA-ECC混凝土柱,分别设置了不同深度的人工裂缝损伤,采用基于压电陶瓷的波动分析法对其进行损伤识别,计算监测信号的小波包能量、功率谱密度以及基于小波包变换的损伤指标.结果随着裂缝深度的增大,小波包能量和功率谱密度均随之减小,且小波包能量与裂缝深度之间存在线性关系,基于小波包变换的损伤指标对损伤程度敏感性较好.结论该监测方法能有效识别PVA-ECC混凝土柱人工模拟的裂缝损伤,研究结果可为PVA-ECC混凝土柱的健康监测提供参考.

Engineered cementitious composite(ECC)is widely used in practical projects such as bridge deck connection and dam repair due to it has significantly improved the toughness,durability and impact resistance of ordinary concrete materials.In order to identify the crack damage of the polyvinyl alcohol-engineered cementitious composite(PVA-ECC),7 PVA-ECC columns with artificial crack damage of different depths were poured in the laboratory.The wave propagation analysis method based on piezoelectric transducer was used to identify the damage and wavelet packet energy,power spectral density and damage index based on the detection signal were calculated.The results showed that the wavelet packet energy and power spectral density both were decreasing with the increase of the crack depth,and there was a linear relationship between the wavelet packet energy and the crack depth.The damage index based on wavelet packet transform was sensitive enough to the level of damage.The detection method can effectively identify the artificial crack damage of the PVA-ECC columns,and the research results can provide a reference for the health monitoring of PVA-ECC columns.