APPLICATION OF THE HILBERT-HUANG TRANSFORM AND ENHANCED NOISE FILTERING TO THE DAMAGE DETECTION OF STRUCTURAL SYSTEMS

摘要

This paper proposes an enhanced noise filtering technique to the Hilbert-Huang transformation technology for the damage detection of structural systems using vibration measurements. The Hilbert-Huang transformation technology is a set of superior algorithms for analyzing non-linear and non-stationary signals and also for linear and stationary signals. However, the signals are filtered by reconstruction from "selected" intrinsic mode functions (IMFs), derived from the original signal through the empirical mode decomposition method. The proposed filtering technique offers the criterion for selecting the IMFs using the orthogonalization coefficient. Through the enhanced filtering, it is possible to increase the accuracy for the estimation of the time-varying system's natural frequency, indicative of the degree of damage, which helps an effective design of a control system.