Modal parameter identification using simulated evolution

A global optimization algorithm based on the Darwinian evolutionary theory is implemented for the identification of modal parameters of linear vibrating structures. The capability of the evolutionary search method in locating the global minimum among numerous local minima is demonstrated. The modal parameter identification procedure is based on the concept of modal sweep, according to which modes of a structure are identified individually and iterativcly. A fast recursive algorithm is also developed for forward response calculation of a linear oscillator to lessen the computational burden of using simulated evolution in the iterative identification process. The proposed modal parameter identification approach does not require any initial estimate of parameter values. Simulation results show that the approach is effective and reliable in identifying dominant modes under noisy conditions.