When Rotorcraft Composites Are Exposed to Extreme Environments

Composite structures are increasingly applied to advanced design concepts of today’s rotorcraft and tiltrotor. In many events, these structures are exposed to extreme environments, the effects of which on structural performance and durability are not fully understood. Previous research has shown that temperature and moisture indeed influence the characteristics and behavior of composite materials. The current practice is to generate material property allowables at room temperature dry and wet (RT-D/W), elevated temperature dry and wet (ET-D/W), and cold temperature dry and wet (CT-D/W), with the temperature values set by the certification agency. The aim of this paper is to present a systematic experimental investigation of extreme environments on the rotorcraft composites. The considered harsh environments are humidity, sand/dust, and salt spray fog mixed with various temperature levels. The resulting material responses are discussed.