Abstract:

：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.

Key words: correlation coefficient, damage index, damage location method, energy spectrum