Effect of Low Temperatures and Moisture on the Strength Performance of Carbon Fiber Reinforced Plastic

The service life of a carbon fiber reinforced plastic used in an aircraft intended for operation under Arctic extreme conditions was studied by longitudinal bend testing in which monotonic loading at various speeds of displacement of the mobile gripper of a testing machine was combined with cyclic loading of specimens with increasing displacement range. The force dependences of the activation energy of failure and the dependences between the failure rate, deformation rate, and service life were characterized. Exposure of the carbon fiber reinforced plastic to subfreezing temperatures was shown to hardly affect the service life. However, periodic transitions through the crystallization temperature of water accumulated in the composite significantly impair its strength performance and safe service life.