Hydrothermal aging of friction riveted thermoplastic composite joints for aircraft applications

In this paper, the sensitivity of carbon fiber reinforced polyether-ether-ketone friction riveted joints to hydrothermal aging was assessed, addressing the degradation mechanisms and post-aged quasi-static mechanical behavior of the joints. The joints were exposed to 71 degrees C and 95% relative humidity for 28 days. Despite the oxidation of the metallic nut and washer as well as cavitation and degradation of the composite, a 23% increase of joint mechanical performance was observed after 28 days of exposure. It is believed that the temperature and water uptake drove matrix post-crystallization at the surface of the fibers, which led to local strengthening of the composite in the rivet surrounding and, consequently, improved the joint residual strength.

Automated summary

This study shows that carbon fiber reinforced polyether-ether-ketone friction riveted joints have a certain resistance to hydrothermal aging, with an increase in mechanical performance observed as exposure time increases.