PSI - Issue 68

Hande Vural et al. / Procedia Structural Integrity 68 (2025) 573–580 / Procedia Structural Integrity 00 (2024) 000–000 Vural et al.

578 6

100

91.95

80.94

80

60

40

20

16.13

12.0512.3912.63

10.1210.7310.8411.14

7.56 Percentage Difference (%)

0

JC

CL

RT

OH

MC

Ayada

Brozzo

Le Roy

Ko-Huh

Ayada-m

Freudenthal

Fig. 3: Percentage di ff erence between predicted and experimental residual velocities for various damage models for 7.62 API projectile in 8 mm single layer. 7.64 API Hemi Blunt T4 T2-2 T2(6)2 T1-3 T3-1 T1-1-1-1 =363 =418 =422 =413 =400 =437 =389 =354 =349 =368 =332 =381 =402 =382 =407 =353 =392 =387 Figure 5 qualitatively compares the trend of ballistic limit velocity di ff erences obtained numerically for Armox 500T with the experimental trend for Q235 steel presented in Deng et al. (2012, 2013). The T4 plate is selected as the reference, and all relative velocities are calculated based on the ballistic limit velocity of this plate for both experimental and numerical results. In the figure, each bar represents the relative ballistic limit velocity calculated with the corresponding damage criterion. For the 7.62 API, the OH model consistently provides the closest predictions in all cases. Ayada-m and Ko-Huh models also perform well compared to other models. For the hemispherical projectile, the MCmodel o ff ers the best predictions in all cases. In contrast to the 7.62 API results, the hemispherical projectile shows a more varied performance across models, while the Ko-Huh and Ayada models give closer predictions than the others. This comparison shows that the choice of damage criterion is critical and may vary depending on the bullet type. The OH model is more suitable for sharp bullets such as 7.62 API, while the MC model provides better performance for hemispherical. The KH model is the criterion that made the second-best predictions for both projectiles. The deceleration behavior of the bullets shows how the damage models influence the reduction in velocity during impact. In Figure 6, the deceleration levels of damage criteria are compared over time for two di ff erent nose shapes. The average ballistic limit velocity for the 7.62 API is 300 m / s, whereas, for the hemispherical projectile, this velocity is 360m / s. At the beginning of the impact, the deceleration values of the 7.62 API are almost the same for all models. However, at the end of the analysis, the JC and KH models exhibited a higher deceleration level compared to the other damage models. For the hemispherical projectile, the JC model shows a lower deceleration during impact, while the Fig. 4: Failure mechanisms of 7.62 API, hemispherical, and blunt projectile at 500 m / s initial velocity for di ff erent configurations. V r is residual velocity and unit is m / s.