PSI - Issue 17

M.P. Tretyakov et al. / Procedia Structural Integrity 17 (2019) 865–871 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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b Fig. 3. Loading diagrams for tests on interlayer shear of glass-plastic samples at different loading rates (a): 0.2 mm / min (solid lines), 2 mm / min (dash-dotted lines), 20 mm / min (dashed lines); loading diagrams at different temperatures (b): 22 º С (black solid line); 100 º С (gray solid line); 135 º С (black dashed line); 150 º С (gray dashed line). According to the test results, characteristic deformation diagrams of fiberglass samples were obtained and the influence of the deformation rate and elevated temperatures on the deformation patterns and the degree of realization of the postcritical deformation stage when testing for interlayer shear was evaluated. An increase in the strain rate leads to large load disruptions at the postcritical stage. An increase in the test temperature leads to a more pronounced realization of the stage of deformation softening of the considered composites, which manifests itself as a gradual decrease in load with an increase in the deflection and an increase in the limiting deformation reached by the time of complete destruction. The test results of CFRP samples at different temperatures are presented as a generalized dependence of the average values of strength during interlayer shear on temperature and loading rates (Fig. 4). Typical loading diagrams at different temperatures are shown in Figure 5. For specimens tested at a loading rate of 0.1 mm/min, when the temperature rises to 120 C, 160 °C and 200 °C, the strength decreases with an interlayer shear of 7 %, 20 % and 76 %, respectively, compared with the values obtained at 22 °C. Similarly, for samples tested at a speed of 1 mm/min, the reduction is 13 %, 20 % and 54 %. For samples tested at a speed of 10 mm/min, the reduction is 10 %, 17 % and 39 %. 3.3 The results of CFRP tests on interlayer shear in a wide range of loading rates and temperatures

Fig. 4. The dependence of the ultimate strength in the interlayer shear on the temperature at various loading rates: 0.1 mm/min (solid line); 1mm/min (dashed line); 10 mm/min (dotted line).