Issue 61

R. Andreotti et alii, Frattura ed Integrità Strutturale, 61 (2022) 176-197; DOI: 10.3221/IGF-ESIS.61.12

Figure 24: 7.62x39 mm FMJ penetration as a function of time. Comparison between experimental results (blue line) and simulation (red line).

Figure 25: 5.56x45 mm NATO impact. Comparison between experimental results (above) and simulation seen from the two cross directions (below). Time = 0.0 ms. The resolution of the checkered ruler is 20 mm. 5.56x45 mm NATO The comparison between real and simulated evolutions of the bullet’s kinematics and the temporary cavity shows a good correspondence all along the block (Fig. 25 to Fig. 32). The bullet’s rotation is almost identical until 0.4 ms. Then, the simulation predicts a continued rotation bringing the bullet to escape the block at around 270 degrees angle. The real rotation of the bullet seems instead to encounter a stall, it is however impossible to clearly identify the position of the real bullet at the escape. The simulation anticipates the escape of the bullet of about 0.2 ms compared to reality. The residual velocity of the real bullet is 152 m/s, while the simulated value is 199 m/s. Therefore, the kinetic energy absorbed by the Baligel block is 1617 J in the real impact, while the simulation predicts an energy absorption of 1584 J. Considering the 0.4 m length of

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