Acoustic emission based flexural characteristics of glass fiber reinforced composites embedded with ZnO nanowhiskers

In recent years, Zinc oxide (ZnO) nanowhiskers, with good functional and mechanical properties, have been used for the preparation of structural and functional composites. However, the reinforcement mechanism of ZnO nanowhiskers in the composites is not fully understood. In this study, three-point bend tests have been carried out to investigate the flexural properties of the composites which contain different amounts of ZnO nanowhiskers. To obtain the reinforcement mechanism of ZnO nanowhiskers, acoustic emission (AE) technique was applied to evaluate the characteristics of the damage progress and the failure mechanism of the specimens. In addition, linear AE source location was also performed to monitor the damage initiation and propagation. The presence of ZnO nanowhiskers in the resin matrix influences the flexural strength and corresponding AE signals during the fracture process of the specimens. The results show that the composites embedded with 15 wt% ZnO nanowhiskers in the resin exhibit the highest flexural strength, AE energy, counts, and the longest duration and also hits of AE source location.