WAVELET TRANSFORM BASED STRUCTURAL DAMAGE DETECTION FOR SUDDEN DAMAGE SITUATION

摘要

Several continuous wavelet transform (CWT) based damage indices and a wavelet damage indices and genetic algorithms (WDI-GA) based damage location procedure have been developed to detect the damage of structures suffering from sudden damage and linear time-vary ing damage. The damage indices are calculated from structural impulse responses. One type of damage indices is obtained from the shape of scalogram of an impulse response at each time instant. The other type of damage indices is related to the ratios of the scalograms of impulse responses at different locations of the structure and at the scale relevant to the frequency of a certain mode. Damage detection problems related to sudden damage situation are discussed in this study. Numerical examples are conducted to investigate the effectiveness of the proposed damage indices for sudden damage situation. The influences of measurement noise on damage detection results are also investigated.