Experimental mechanical characterization of carbon and glass fiber epoxy composite laminates with delamination

Abstract

Helicopter rotor blades made of composite materials operate in a highly dynamic and unsteady aerodynamic environment, sometimes resulting in delamination and cracking of the blade skin. In this study, the in-plane tensile and flexural properties of [(0/+/- 45/90)2]f and [(+/- 45)8]f woven carbon and glass fiber-epoxy matrix composites, which are commonly used as blade skin materials, were investigated experimentally under tension and bending loads using ASTM standards. A skinny anti-adhesion PTFE tape was placed in the neutral plane of the samples while laying to artificially generate delamination. The results revealed that carbon woven fiber epoxy laminates are preferable owing to their rigidity, strength, and low density. However, with a significantly more brittle structure, carbon fiber epoxy laminates are more sensitive to delamination; therefore, tighter control measures are necessary during both manufacturing and operation.