一种基于波信号能量谱相关系数的损伤定位方法

基于波信号能量谱的相关系数,采用了两种策略分别计算传感线路的损伤特征参数(Damage index,DI),策略一:计算一条传感线路的感应波信号能量谱在基准和检测两种状态下的相关系数,并把该系数作为该条传感线路的DI。策略二:首先计算一条传感线路的激励波与感应波信号的相关系数,并把检测状态的相关系数相对于基准状态的相关系数的变化量作为该条传感线路的DI。在检测一个具有加强筋的复合材料板结构时,结合所计算的DI和损伤定位方法获取锥形孔损伤的概率分布图。试验结果表明策略二比策略一定位损伤的精度更高。这是由于策略二有效地避免了基准状态和检测状态的激励波信号的微弱差异所导致的损伤识别误差。

A Damage Location Method Based on The Correlation Coefficient of Energy Spectrum for Wave Signals

In order to avoid damage identification error, which is caused by the activated signal differences between benchmark and damage cases, a method of calibrating damage index (DI) based on the correlation of energy spectrum is promoted. Two schemes are developed to calibrate DI. Scheme I:analyze the correlation of energy spectrums of captured wave signals between benchmark and damage cases for a sensing path, and take the correlation coefficient as DI. Scheme II:firstly, calibrate the correlation coefficient of energy spectrums of the activated wave signal and captured wave signal for a sensing path, and then the variation of correlation coefficient for damage case relative to that for benchmark is taken as DI. In experiment, a cone hole in composite plate is located by integrating the calibrated DI with a damage location method. Results demonstrate that the scheme II is competent for identifying damage more precisely than the scheme I, avoiding the error induced by the activated signal differences between benchmark and damage cases.