Study on the Moisture Absorption and Bending of Carbon Fiber Composite Material

The research object of this paper is a kind of carbon fiber composite material that is used in a special UAV in a certain marine area. The purpose of the research is to understand the material properties of this composite in extreme hot and humid environments. First of all, this material was subjected to a 24-hour cycle damp heat test that lasted sixty days. The test temperature was 70°C and the relative humidity is 85%. The results of the damp heat test basically reflected the hygroscopic property of the composite material accorded with Fick's first law. Secondly, since the components of the UAV structure that use this material are primarily subjected to bending loads, three-point bending tests were conducted with the specimens subjected to different stages of damp heat tests. Finally, the decay of the bending properties of this composite material in the hygrothermal condition was obtained by the experimental data analysis, which provides technical support for its applications in engineering. Keywords-Carbon Fiber Composite Material; Damp Heat Test; Hygroscopic Property; Three-Point Bending Test