Structural health monitoring based on HHT

Based on this adaptive data analysis a new method for nondestructive instrument method to monitor the health of a bridge has been developed. This new method is based on a transient test load and simple data collection. The nuclear of the method is the data analysis based on the HHT method for nonstationary and nonlinear time series analysis which consisted of the Empirical Mode Decomposition and Hilbert Spectral Analysis. The final decision on the health of the bridge structure is based on the nonlinear characteristic of the bridge responding frequency under different loading conditions and on the comparison between the free and the forced vibration frequencies all analyzed with HHT. Thus this alternative method enjoys many advantages: no a priori data required simple data collection minimum traffic disruption.