Structural damage detection based on cross-correlation function with data fusion of various dynamic measurements

Abstract

To take advantage of various types of dynamic measurement data for structural damage detection, an identification strategy based on cross-correlation function with data fusion of various dynamic measurements was proposed to improve the accuracy of damage identification in the present study. First of all, the cross-correlation functions among the easily acquired strain, acceleration, and displacement responses were theoretically derived when the structure was subjected to ambient excitations. Furthermore, an identification strategy was proposed for structural damage detection with the objective function of minimizing the difference between the measured and computed cross-correlation function under multiple unknown ambient excitations. In the proposed strategy, four optimization methods, namely, gradient search, genetic algorithm, particle swarm optimization, and the hybrid method of particle optimization method and gradient search were applied as the search engine to identify structural unknown damage index. Moreover, the performance of the proposed identification strategy was examined by the numerical studies on a two-dimensional and a three-dimensional truss as well as the experimental study on a cantilever beam. These results showed that the cross-correlation function among different types of vibration measurements could significantly improve the accuracy of the identification results, meanwhile, the proposed strategy exhibited excellent robustness to the measurement noise. In addition, the performance of the proposed strategy with different combinations of vibration data and the influence of reference data on the accuracy of damage identification results were further investigated.