Random vibration response-only damage detection for a set of composite beams

摘要

The problem of random vibration response-only damage detection for a set of composite beams, each representing the boom of an unmanned aerial vehicle connecting the tail to the fuselage, is considered. Twenty six (26) like specimens, exhibiting material and manufacturing variability, are used. Two non-parametric and one parametric statistical time series type damage detection methods using response-only signals are employed. The first is based on the Power Spectral Density (PSD) of a single response, the second on the Transmittance Function (TF) between two responses, and the third on changes in the parameter vector of an AutoRegressive (AR) model representing a single response signal. All methods are trained in a baseline phase using vibration acceleration response signals acquired from a single healthy beam. Their effectiveness is evaluated in the inspection phase, using signals obtained from the remaining twenty five (25) beams, three (3) of which have suffered impact damage. The results illustrate the problem of degraded detection performance caused by material and manufacturing variability among the beams. The parametric, AR based, method is however shown to exhibit effectiveness and robustness.