Effects of ultraviolet radiation and condensation on static and dynamic compressive behavior of nanophased glass/epoxy composites

Abstract

Increased use of fiber reinforced polymeric composites in an outdoor environment has led to questions concerning their environmental durability, particularly as related to ultraviolet (UV) radiation, moisture, and temperature exposure. This chapter describes the effects of UV and UV radiation + condensation (UC) on the static and dynamic compressive properties of unidirectional glass/epoxy composites. The samples were manufactured using an infusion process with and without nanophased epoxy and exposed to UV radiation and UC conditioning for 5, 10, and 15 days respectively. Nanophased epoxy was prepared with 1 wt%and 2 wt% nanoclay. Static compression tests were carried out using MTS test system under displacement control mode at a crosshead speed of 1.27 mm/min. Dynamic compression tests were carried out using modified Split Hopkinson Pressure Bar (SHPB) at different strain rates. The compressive strength and stiffness were evaluated as functions of strain rate. Results of the study showed that samples lost weight when exposed to UV radiation, whereas they gained weight when exposed to UC conditioning. Weight gain or loss was lower for nanophased composites when compared to neat samples. Static and high strain compressive properties reduced for all the nanophased samples when compared with room temperature samples. However, the loss in compressive properties was lowest in nanophased composites with 2 wt% nanoclay.