A new non-linear impact resonance acoustic spectroscopy algorithm: FANSIRAS

Nonlinear hysteretic techniques have demonstrated their suitability for damage detection in mesoscopic materials. These methods are mainly based in the evaluation of the frequency and damping shifts with the increasing strain amplitude under dynamic conditions. A deep understanding of the impact reverberation phenomena has been achieved in order to introduce a novel signal processing approach called FANSIRAS (Flipped Accumulative Non-linear Single Impact Resonance Acoustic Spectroscopy). This brand new procedure respects the underlying phenomena, composed of both an exponentially decaying signal and a time varying phase signal, which results in the feasibility of using a single impact to evaluate the non-linear features of damaged materials. The traditional acoustic spectroscopy technique, NIRAS (Non-linear Impact Resonance Acoustic Spectroscopy), and FANSIRAS have been analyzed and compared when providing quantitative information related to the degree of damage. In this work, both techniques were applied...