How does “listening” help fracture understanding?

How does “listening” help fracture understanding?

de Araujo Alves Lima, Rosemere (TU Delft Structural Integrity & Composites)
Tao, R. (TU Delft Structural Integrity & Composites)
Bernasconi, A. (Politecnico di Milano)
Carboni, Michele (Politecnico di Milano)
Carrere, Nicolas (ENSTA)
Teixeira De Freitas, S. (TU Delft Structural Integrity & Composites)

2023

Understanding the relationship between the sensors’ outputs and the damage evolution within the joints is becoming increasingly crucial to improving structural health monitoring systems and collecting data to improve the joint’s design. Therefore, a study of the acoustic emission method associated with visual fracture evaluation was proposed to give insights into the toughening of composite bonded joints and better understand the relationship between the acoustic emission features and the damage mechanism involved. Thus, two different layups were proposed for the substrates: [0]8 and [0/902/0]S. In addition, a toughened epoxy adhesive with an embedded carrier (AF163-2k) was used to bond the substrates. Five specimens of each stacking sequence were tested under quasi-static mode I loading conditions. A travelling microscope and a regular digital camera were used on the lateral sides of the specimens to track the crack propagation paths. One piezoelectric sensor linked to the AMSY-6 Vallen system was used to assess the acoustic emission features produced within the joints during the tests. Unsupervised machine learning algorithms based on artificial neural networks and the Morlet continuous wavelet transformation were used to pattern recognition of the acoustic emission data. Self-organising maps, together with k-means algorithms, were used for data clustering. Following that, the acoustic emission features of each cluster were associated with the insights obtained from the crack propagation images. Finally, it was observed that the different layups triggered simultaneous toughening mechanisms. The combination of the acoustic emission and the visual evaluation was crucial for a deeper understanding of the underlying phenomena.

acoustic emission
Toughening mechanisms
Adhesively bonded joints
Artificial Neural Networks

http://resolver.tudelft.nl/uuid:833c58fb-c3b9-478c-8d8a-9f8fd99d8fde

3rd Benelux Network Meeting and Workshop on Damage and Fracture Mechanics, 2023-05-25, Antwerp, Belgium

Institutional Repository

poster

© 2023 Rosemere de Araujo Alves Lima, R. Tao, A. Bernasconi, Michele Carboni, Nicolas Carrere, S. Teixeira De Freitas