基于互相关函数幅值向量和小波变换的复合材料结构损伤检测

DAMAGE DETECTION OF COMPOSITE STRUCTURES BY A HYBRID METHOD COMBINING CORV AND WAVELET TRANSFORM

提出了一种基于互相关函数幅值向量(Cross correlation function amplitude vector,CorV)和连续小波变换(continuous wavelet transform,CWT)联合检测损伤的方法。选取双正交小波函数,首先计算随机激励下完好结构和损伤结构的互相关函数幅值向量,再分别对其进行连续小波变换,根据损伤前后小波系数的变化来检测结构的损伤,并以小波系数差的模最大值作为损伤指标来进行损伤定位。该方法无需对结构建模,仅需获取结构损伤前后的时域响应信号。通过对带有不同位置分层损伤的复合材料层合梁和层合板损伤检测的数值仿真,验证了用该方法检测复合材料结构分层损伤的有效性。

A hybrid method combining the correlation function amplitude vector(CorV)and the continuous wavelet transform (CWT) was proposed to detect damage of composite structures.In the method,only the time domain signals of the intact and damaged structure were required in the detection procedure.The CorVs between the time domain responses of the intact and damaged structures under steady random excitation were calculated and then analyzed by continuous wavelet transform,where the biorthogonal wavelet function was adopted.The damage of the structure can be identified by the difference between wavelet coefficients of the intact and damaged structures.The damage location was determined by the maximum value of the modulus of the coefficients difference obtained from CorVs.The feasibility and effectiveness of the proposed hybrid method is verified by numerical simulations of delamination damage detection of a composite beam and a laminate plate.