Monitoring the Damage State of Fiber Reinforced Composites Using an FBG Network for Failure Prediction

• Published in: Materials Vol. 10; no. 1; p. 32
• Main Authors: Kocaman, Esat Selim, Akay, Erdem, Yilmaz, Cagatay, Turkmen, Halit Suleyman, Misirlioglu, Ibrahim Burc, Suleman, Afzal, Yildiz, Mehmet
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.01.2017; MDPI
• Subjects: Aeronautics; Bragg gratings; Composite materials; Damage; damage monitoring; Epoxy matrix composites; fatigue; Fatigue failure; Fatigue tests; Fiber composites; Fiber reinforced polymers; fibre Bragg grating; Fracture mechanics; Glass fiber reinforced plastics; Glass-epoxy composites; Manufacturing; Materials fatigue; mechanical testing; Monitors; Networks; Optical measuring instruments; Optics; polymer-matrix composites; Sensors; Strain; Strain gages; Strain gauges; Structural health monitoring; polymer-matrix composites; fatigue; fibre Bragg grating; mechanical testing; damage monitoring
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma10010032

A structural health monitoring (SHM) study of biaxial glass fibre-reinforced epoxy matrix composites under a constant, high strain uniaxial fatigue loading is performed using fibre Bragg grating (FBG) optical sensors embedded in composites at various locations to monitor the evolution of local strains, thereby understanding the damage mechanisms. Concurrently, the temperature changes of the samples during the fatigue test have also been monitored at the same locations. Close to fracture, significant variations in local temperatures and strains are observed, and it is shown that the variations in temperature and strain can be used to predict imminent fracture. It is noted that the latter information cannot be obtained using external strain gages, which underlines the importance of the tracking of local strains internally.