基于压电陶瓷的混凝土裂缝损伤监测

Crack Monitoring of Concrete Beam Based on Piezoelectric Sensor

压电陶瓷的正逆压电效应决定其既可作传感器又可作驱动器。将压电陶瓷埋于混凝土中并对其施加激励,可在混凝土中产生应力波。根据该波动法原理,应用自行研制封装的压电陶瓷传感器对混凝土中裂缝损伤的产生过程进行监测。采用基于小波包分析法定义的损伤指标对不同工况下的损伤进行计算,结果表明,损伤指标的变化趋势与相应的应变片监测信号和荷载位移曲线的发展趋势吻合良好,实现了对混凝土中微小裂缝损伤的监测和识别。

The piezoelectric ceramic material can be used as sensor and actuator according to its direct and converse piezoelectric effect. Actuating PZT embedded in concrete will generate the elastic waves. Based on this theory, the crack process in concrete was monitored with the PZT transducers. The damage index in different working condition was calculated based on the wavelet package analysis. The result indicated that the change of the damage index was consistent well with the trends of the strain gauge and load-displacement curve. Thus the micro-cracks in concrete can be detected and monitored.