Title: Effects of high operating temperatures and holding times on thermomechanical and mechanical properties of autoclaved epoxy or carbon composite laminates

Abstract

The elevated operating temperature is considered an essential factor affecting the performance of laminated composite structures. Under the intended conditions of use in aircraft engines and nacelles, carbon fiber reinforced polymers are exposed to temperatures ranging from room temperature to 120°C. The present work concentrates on the thermomechanical and mechanical properties of autoclaved woven carbon fiber/epoxy composite laminate subjected to different operating temperatures (60, 120, and 180°C) and holding times (10, 30, and 60 min). Thermomechanical results showed that the rigidity and stiffness of the epoxy resin matrix decrease with increasing temperature. However, all mechanical properties (laminate compressive modulus, laminate compressive strength, and interlaminar shear strength) decreased progressively with operating temperature. Laminate compressive strength and interlaminar shear strength were seen to decline up to 43.74% and 30.60% on the operating temperature of 180°C, respectively, compared to measured values at 60°C. This study indicates that only the compression properties were affected by the holding time, while the interaction between the operating temperature and holding time affects the laminate compressive modulus.