PSI - Issue 32

A.M. Ignatova et al. / Procedia Structural Integrity 32 (2021) 79–86 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Impact condition (II). Potassium fluorphlogopite sample was fixed by the mechanical clamp, and the clamp with the sample was rigidly fixed in a holder (fig. 4, b). For the aforementioned types of loading, the following experiments have been arranged: ball velocity 230 m/s collision angle 90º; ball velocity 120 m/s collision angle 90 º; ball velocity 230 m/s collision angle 30º; ball velocity 120 m/s collision angle 30 º. Overall, 8 experiments were conducted, 4 for each ty pe of loading. 4. Results and discussion Appearance of samples after impact in non-constrained conditions is shown in fig. 5, in constrained conditions in fig. 6. Fig. 7 shows distribution of destruction fragments by size depending on the type of destruction, fig. 8 and 9 show distribution of destruction fragments by sphericity coefficient and convexity coefficient, respectively. Table 1 contains average parameters of destruction fragments in all experiments. a b c d

Fig. 5. Potassium fluorphlogopite samples after impact with a steel ball in non-constrained conditions: ( а ) at a velocity of 230 m/s, collision angle 90º; (b) at a velocity of 120 m/s, collision angle 90 º; (c) impact at a velocity of 230 m/s, collision angle 30º; (d) impact at a velocity of 120 m/s, collision angle 30º . a b c d

Fig. 6. Potassium fluorphlogopite samples after impact with a steel ball in constrained conditions: а –at a velocity of 230 m/s, collision angle 90º; b – at a velocity of 120 m/s, collision angle 90 º; c – at a velocity of 230 m/s, collision angle 30º; d –at a velocity of 120 m/s, collision angle 30 º . Functions of distribution of fragments by size in non-constrained and constrained destruction conditions are exponential, which corresponds to the behavior of brittle materials; however, functions corresponding to constrained conditions are better described by normal distribution. There is a statistically significant difference between