The Research Of Thermo-Cycling And VUV Radiation Effects On The Performance Of Space Inflatable Structural Materials

With the increasing demand for further space resources, people pay more attention to the space inflatable deployment techniques, in which space material technique is one key problem. Surface materials of the space inflatable structures would be influenced by vacuum thermo-cycling and vacuum ultraviolet (VUV) when the spacecrafts operated in low earth orbit. In this paper, the vacuum thermo-cycling effects and vacuum ultraviolet effects on space inflatable structural materials were analyzed based on a thorough survey over the studies done through flight tests, ground simulation experiments and theoretical research. The main contents of this thesis are as follows: The performance damage effects of thermo-cycling on space inflatable structural fabric carbon fiber reinforced epoxy laminates (CF/EP), aluminized Kapton (Al/Kapton) films which used as reflector of space inflatable antenna were investigated by a temperature range of -120℃～120℃with the vacuum degree 10-5 Pa which conducted with space environment ground-based simulation facility. A gas-jet-type VUV source that can give a spectrum in the wavelength range of 5~200nm was used in this paper to research of VUV radiation effects on Upilex films which used as canopy of the space inflatable antennas and Al/Kapton films.The tensile strength and Young's modulus of CF/EP specimens before and after vacuum thermo-cycling were measured by an electrical universal material testing machine. An electron scanning microscope was used to perform the surface morphology and fractography of specimens. Theoretical models were used to predict the effects of microcrack-density to effective tensile modulus of CF/EP laminates for long-term duration exposure for it difficult to get from tests. A uniaxial zero-expansion model was established based on the analysis of thermal stress and the coefficient of thermal expansion of the laminates. Zero-expansion models satisfy the request of space structures for they can possess high dimensional stability in temperature-change fields.The surface morphology, electrical conductivity and spectral reflectivity of Al/Kapton films before and after space environment simulated tests were...