Acoustic Emission Testing and I<i>b</i>-Value Analysis of Ultraviolet Light-Irradiated Fiber Composites

Abstract

The failure behavior of composites under ultraviolet (UV) irradiation was investigated by acoustic emission (AE) testing and Ib-value analysis. AE signals were acquired from woven glass fiber/epoxy specimens tested under tensile load. Cracks initiated earlier in UV-irradiated specimens, with a higher crack growth rate in comparison to the pristine specimen. In the UV-degraded specimen, a serrated fracture surface appeared due to surface hardening and damaged interfaces. All specimens displayed a linearly decreasing trend in Ib-values with an increasing irradiation time, reaching the same value at final failure even when the starting values were different.

Keywords

• acoustic emission
• fiber-reinforced composite
• I<i>b</i>-value
• photodegradation