In-situ health monitoring of thermoplastic bio-composites using acoustic emission

This article aims to accomplish research's that has been achieved recently in the scientific community on the manufacturing monitoring and structural health monitoring (SHM) of composite materials using in-situ piezoelectric sensors. A series of specimens of flax/Elium composite laminates with and without integrated piezoelectric sensors were subject to static and fatigue tensile tests. The effects of introducing the sensor into the composite materials were studied. Moreover, the Acoustic Emission (AE) method was used during experimental tests to follow the gradual degradation and damage evolution in the bio-composites. The AE data were analyzed by the k-means unsupervised pattern recognition algorithm. Moreover, the characteristics of the acoustic signals detected from specimens with and without integrated sensors were compared. The experimental results show that the integration of piezoelectric sensors within the flax/Elium composite without degrading its mechanical properties is possible. In addition, the integrated sensor shows good results regarding class detection and separation. The in-situ health monitoring methods performed on bio-composites presents an excellent alternative to the conventional technique in which sensors are generally bonded to the material surface.