基于“能量-故障”的复合材料层合板裂纹损伤检测与识别

Intelligent Detection and Identification of CrackDamage of Composite Laminated Plate

对一含裂纹的复合材料层合板,通过粘贴在其表面一对压电片(一片作为传感器,一片作为激振器)构造了结构动力响应的激励和检测系统。通过完好板和损伤板的振动模态参数和时域响应信号比较,探讨了识别复合材料结构损伤的可行性。同时,利用小波包分析,基于动力响应信号各频率段的能量分布,提取结构损伤的特征量来表征结构损伤情况。结果表明,当用一个含有丰富频率成分的信号作为输入对系统进行激励时,可以较为准确地识别复合材料结构的裂纹损伤。

We are the first in P. R. China to propose an intelligent system for detecting damage in composite structures. Our method takes into consideration recent developments in intelligent materials and structure and in wavelet analysis. In our method, we glue a pair of piezoelectric patches on composite laminated plate, one as actuator, and the other as sensor. By applying an electric field to the actuator piezoelectric patch, we excite mechanical vibrations and we collect the dynamic responses with the sensor piezoelectric patch. Section 2 discusses how to extract with the wavelet transform the feature of energy distribution of the plate with crack damage and it can be used to identify the very small difference in dynamic response signal between the damaged plate and the original undamaged plate. Numerical results in section 2 show that very small crack propagation can be detected by our method. The proposal of our method will be followed by systematic experiments.