Degradation Entropy: An Acoustic Emission Based Approach to Structural Health Assessment

Abstract

This paper reports experimental estimation of the relative entropy associated with acoustic emission obtained in the course of the fatigue degradation of the Al 7075-T6 specimens. A non-parametric approach is employed to quantify the relative entropy of the acoustic emission signals. The trend in the evolution of the cumulative relative entropy corresponds to of the cumulative damage in the tested specimens. We also examine the hypothesis of a constant cumulative acoustic emission entropy at the instant of crack initiation.