Modal parameter identification of a Rigid Frame-Continuous Girders Bridge under ambient excitation by Fast Bayesian FFT method

摘要

Bayesian theory is adopted in modal parameter identification, finite element model updating and residual capacity evaluation of the structures recently. Fast Bayesian FFT modal identification approach provides a rigorous way to obtain modal parameters and well-separated modes using the fast Fourier transform under ambient excitation. Moreover, it avoids choosing the modal order or removing false modes based on the stable diagram and has its obvious advantages. In this paper, modal parameters of a rigid frame-continuous girders bridge under ambient excitation are identified by this approach. Comparison with stochastic subspace identification (SSI) method indicates that Fast Bayesian FFT is a good approach to identify the modal parameters even for a large number of measurement channels.