Evaluation of Mechanical Properties of Carbon/Epoxy Composites Under Space Thermal Environments

This study evaluates the mechanical properties of carbon/epoxy composites under space thermal environments. The mechanical properties and the coefficient of thermal expansion of the carbon/epoxy composite for application to the landing device of the lunar module in the operating thermal environment were evaluated at test temperatures of-150 degrees C, 25 degrees C and 120 degrees C. The tensile and compressive properties of the fiber direction (0 degrees) and fiber transverse direction (90 degrees), in-plane shear, and interlaminar shear strengths as well as coefficient of thermal expansion of the fiber direction, fiber transverse direction, and epoxy were evaluated. For the fiber direction (0 degrees) specimens, which had a dominant influence on the mechanical properties of the fiber, it is similar to the mechanical properties at roomtemperature in cryogenic and high-temperature environments. However, for the fiber transverse direction (90 degrees) specimens, which were predominantly affected by the resin properties, extremely large deviations were identified. These deviations were due to the thermal characteristics of the epoxy material.