复合材料结构损伤联合定位法试验研究

Experimental Investigation on a Combined Damage Localization Method for Composite Beams and Plates

提出了复合材料结构损伤联合定位法,该法需首先获得复合材料结构在随机激励下的振动响应信号,计算结构的互相关函数幅值向量,通过对损伤结构的互相关函数幅值向量进行光滑拟合作为参考向量,再对损伤情况下的互相关函数幅值向量和参考向量分别进行连续小波变换,得到各自的小波系数,进而求得小波系数差的模,根据小波系数差的模的极值进行损伤的定位。该方法无需进行结构建模和模态识别,在无完好结构信息的情况下就可准确进行损伤定位。最后,还通过蜂窝夹层梁和玻璃纤维层合板的损伤检测试验,验证了该方法的有效性。

A combined method of damage detection for composite structures is proposed.In this method,only the vibration responses of the damaged structure are measured under a steady random excitation in order to calculate the cross correlation function amplitude vector(CorV).A reference CorV is obtained by smoothing curve fitting of the measured CorV of the damaged structure in a least-squares sense.Then,the continuous wavelet transform is applied to the measured CorVs and the reference CorVs respectively.The modul of difference between the wavelet coefficients of measured CorVs and reference CorVs are calculated as the index of damage localization.The validity of the proposed method is verified by experiments on a composite honeycomb beam with prefab debonding damage and a composite laminate plate with prefab delamination damage.