Non Destructive Evaluation and Structural Health Monitoring of structural materials by means of nonlinear acoustics and acoustic emission
Résumé
Damage characterization of structural heterogeneous materials as concrete, rocks, or composites by classical linear acoustical methods does not generally give the expected sensitivity to early damage detection. As such, acoustical nonlinear methods appear like an interesting alternative. In this contribution we present a NonLinear Resonance Spectroscopy (NLRS) approach and use some NLRS features as Resonance frequency shift, Q-factor change as a function of the peak amplitude and Acoustical Slow Dynamics (ASD) to characterize damage in concrete and polymer-based composite. Materials are characterized at intact and gradually damaged states. Besides, damage was monitored using the Acoustic Emission (AE) generated by the material during the damage process. A classification of the AE signals is proposed to identify the different damage mechanisms and to understand their contribution to the evolution of the NonLinear behaviour of the materials under investigation. In this contribution we report observations of non linear features corresponding to a polymer-based composite sample taken at the intact as well as progressively damaged states. These features are correlated to Acoustic Emission data recorded during the different damage steps. This work shows the relevance of this approach in developing new highly sensitive methods for Non Destructive Evaluation and Structural Health Monitoring purpose.
Domaines
Acoustique [physics.class-ph]
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