Feature Extraction for Damage Detection in Structures Based on Nonlinearity Analysis

In the present study, a nonlinear system identification approach known as NARMAX (Nonlinear Auto-Regressive Moving Average with eXogenous Inputs) modelling method and the NOFRF (Nonlinear Output Frequency Response Function) are introduced to detect damage in plate. A set of NOFRF-based damage features is proposed, and the procedure about how to extract the features from the measured response data is presented in detail. An experimental application to the detection of damages in aluminium plates demonstrates the effectiveness and engineering significance of the new damage detection technique.