Abstract:

The aim of this research is to identify the damages of bridges by using relatively simple methods and to monitor the health situations of the bridge structures.Th is research is based on the fact that cracks usuallv exist in the form of crack groups. By analyzing the relationship between the Lipschitz exponent and the wavelet vanishing moment,the characteristics of the signal breaking points are expressed. based on the multi.scale change rules of the maximum value of wavelet transform.Thus,a method is proposed to determ ine whether there exist singularitiv points in the signal.and where the singularity points are located.By applying the proposed theory to the static force simulation of the finite element model for simple-supported beams with cracks.the oceurrence and location of the crack groups are then determ ined.Th e results indicate that the proposed method is of greater precision, more facili-ty and lower cost than the conventional method.

Key words: structural crack group, wavelet transform, damage detection, numerical simulation, Lipschitz exponent