Analysis of failure mechanisms of degraded hybrid glass-carbon composites in acidic medium: Insights from acoustic emission analysis

• Published in: Engineering failure analysis Vol. 134; p. 106082
• Main Authors: Amini, Mohammad, Gazik, Reza Amini, Honarvar, Farhang, Montazeri, Abbas
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2022
• Subjects: Acoustic emission testing; Damage mechanisms; Degradation; Hybrid composites; Scanning electron microscopy; Hybrid composites; Acoustic emission testing; Degradation; Scanning electron microscopy; Damage mechanisms
• ISSN: 1350-6307; 1873-1961
• DOI: 10.1016/j.engfailanal.2022.106082

[Display omitted] •A hybrid carbon-glass composite is developed utilizing vacuum bag molding.•AE method and SEM observations are implemented to explore the damage mechanisms.•An additional group of AE signals is identified for the exposed samples.•The amplitude of exposed samples decreases due to acid penetration.•The stress induced by ion exchange mechanism leads to fiber scission. In this paper, the failure mechanisms of environmentally degraded hybrid glass/carbon fiber reinforced epoxy composites that are subjected to tensile loading are examined. The test specimens are manufactured by vacuum bag molding and the hybrid laminates are exposed to 5 wt% nitric acid at room temperature. The study is carried out by using a combination of Acoustic Emission (AE) nondestructive testing and scanning electron microscopy. Matrix cracking, matrix-fiber debonding, and fiber failure are found to be the main causes of reduction of mechanical properties of the exposed specimens. Unlike the control sample, the exposed specimens show an additional group of acoustic emission events that could be correlated to a delamination between glass and carbon fiber layers. It can be concluded that the synergistic effect of the corrosive environment and stress induced by ion exchange phenomenon has led to fiber scission; which in turn has reduced the load-bearing capabilities of the composite specimens.