Characteristics of Detect Index for Structural Small Damage Based on Wavelet Analysis Under Strong Background Noise

This paper presents a study on the effect of input noise on the detect index of structural damage. The main procedures include that, for some structures with small damage, the different dynamics response are obtained under the given input function and various input noise level, and then, the structural damage index is constructed using the energy spectrum of the sub-signal decomposed by wavelet analysis. Results show that the relationship between the different input noise level and the damage index is nonlinear, and some optimal signal/noise ratio can be found in order to obtain the most sensitive damage index to small structural damage.