PSI - Issue 50

S. Lobanov Dmitriy et al. / Procedia Structural Integrity 50 (2023) 163–169 Lobanov Dmitriy S. et al./ Structural Integrity Procedia 00 (2022) 000 – 000

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Fig. 2. Dependence of the interlaminar shear strength for STEF specimens on elevated temperature.

An assessment of moisture saturation of glass and carbon fiber samples after preliminary thermal and moisture aging in aggressive environments was carried out. Dependence diagrams of the aggressive environment influence such us temperatures and duration of exposure (days) on the residual strength properties of composites are plotted. The dependencies of the change in residual strength during interlayer shear after thermal and moisture aging for 30 days are shown in Fig.3.

Fig. 3. Diagrams of average values of dispersion of strength at interlayer shear tests of fiberglass samples after thermal and moisture aging at temperatures of 22 º С (red column), 60 º С (blue colu mn) and 90 º С (green column) for 30 days relative to the average value for samples without aging (gray column) Statistical assessment of the obtained results significance is presented in the work [Lobanov et al. (2022)]. Also, the microstructure of the fiberglass sample's surface was studied before and after thermal and moisture aging in an unloaded state using a Carl Zeiss SteREO Discovery V12 stereo microscope. The results of the microstructure study made it possible to fix the preliminary thermal modes and moisture exposure, in which the appearance of surface defects in fiberglass samples in an unloaded state occurs.