基于压电传感器的纤维陶粒混凝土冻融损伤检测

Freezing-thawing Damage Detection of Fiber Ceramsite Concrete Based on Piezoelectric Sensors

针对纤维陶粒混凝土低温下受到冻融损伤导致影响结构安全性问题,基于压电陶瓷传感器进行损伤检测。利用压电传感技术对冻融后的纤维陶粒混凝土试件进行检测,获得不同冻融次数下的应力波信号。当冻融次数增加,试件相对动弹模量和抗弯强度下降,压电陶瓷检测到的应力波信号幅值相应减小,基于应力波的衰减,采用小波包能量分析法将其转化为损伤指数,与冻融试验评价指标损伤程度和抗弯强度损失率进行拟合,吻合度较高。结果表明,纤维陶粒混凝土损伤指数与冻融损伤程度和抗弯强度损失率相关性较强,该纤维陶粒混凝土冻融损伤无损检测方法具有良好可行性。

A damage detection method based on piezoelectric ceramic sensor was proposed in this paper to solve the problem that the structural safety of fiber ceramsite concrete is affected by freeze-thaw damage at low temperature.Piezoelectric sensing technology was used to detect the fiber ceramide concrete specimen after freezing and thawing,and the stress wave signals under different times of freezing and thawing were obtained.With the increase of freezing-thawing times,the relative dynamic modulus and flexural strength of specimens decreased,and the amplitude of stress wave signal detected by piezoelectric ceramics decreased accordingly.Based on the attenuation of stress wave,wavelet packet energy analysis method was used to convert the signal into damage index,which was fitted with the evaluation index of damage degree and flexural strength loss rate of freezing-thawing test with high consistency.The results show that the damage index has strong correlation with the degree of freeze-thaw damage and the loss rate of flexural strength of fiber ceramide concrete,and the nondestructive detection method of freeze-thaw damage of fiber ceramide concrete is feasible.