基于压电传感器的木材轴压损伤监测

Timber Axial Pressure Damage Monitoring Based on Piezoceramic Sensor

木结构在受压荷载作用下,会造成木材承载力不足及内部损伤,但对木结构进行无损监测的方法较少。该文基于压电传感器对木材在轴压和局压作用下进行了损伤监测可行性研究,在木材表面贴装压电传感器,利用应力波的主动传感方法,以一个压电传感器作为信号发射器,另一个压电传感器作为信号接收器,在木材结构产生损伤时,监测到的应力波相应减小。基于应力波的衰减,可以采用小波包能量法将其转换为损伤指标,以此来监测结构损伤。结果表明,压电信号幅值与木材的损伤程度相关性较强,该木材无损监测方法具有良好可行性。

Under the action of compressive load,the wooden structure will cause insufficient bearing capacity and internal damage.However,there are few methods for non-destructive health monitoring of the wood structures.In this paper,the feasibility of damage monitoring of timber under axial and local pressure was studied based on the piezoceramic sensor.The piezoelectric sensors were mounted on the surface of the timber,by using the active sensing method of stress wave;one sensor was used as the signal transmitter and the other as the signal receiver;when the timber structure was damaged,the detected stress wave decreased correspondingly.Based on the attenuation of the stress wave,the wavelet packet energy method can be used to convert it into damage indicators to monitor structural damage.The results show that the amplitude of the piezoelectric signal has a strong correlation with the degree of wood damage,and the wood non-destructive monitoring method has good feasibility.