Исследование влагопоглощения авиационных углепластиков в условиях теплого влажного климата

Abstract

Long-term moisture absorption of aeronautical carbon fiber reinforced plastic based on epoxide in conditions of warm humid climate is studied (city of Sochi). The phenomenon of cyclical stochastic fluctuation of moisture absorption of seasonal nature in samples, placed in open atmospheric stand of the climate platform, is established. Thermal-moisture characteristics of the air layer near the sample surface during insolation are examined. They determine the front surface overheating of the sample and the humidity gradient change of the near-surface air layer relative to meteorological data. The layer size, which is 6-8 mm from the sample surface, is found by direct measurements. It depends not only on the intensity of the insolation, but also on the convection and wind heat exchange with the surrounding atmosphere. During summer insolation, the maximum temperature of the sample front surface (Т) in open atmospheric stand reached 54,0oC, and the relative humidity (RH) in the near-surface layer did not exceed 12, 9 %. Regarding the atmospheric meteorological parameters, this indicates an overheating of the surface by 24,7o C and a decrease in the near-surface RH by 46, 1%. The obtained data exceed daily fluctuations of atmospheric parameters for T by 4 times and for RH by 3 times. The importance of the obtained results is determined by the fact that cyclic changes in the sample surface temperature result in aging of aeronautical carbon fiber- reinforced plastic. They contribute to the development of physical and chemical processes in the material and during the operation of products (25-30 years) they can significantly reduce their strength properties.