Estimation of penetration equation parameters by comparing numerical analysis and experimental results

Abstract

Penetration analyses are needed to improve the survivability of combat vehicles. The penetration analysis can be achieved by numerical analysis or experiments. Because excessive time is required to obtain results in both cases, it is needed to derive a penetration equation using numerical analysis. But, the constants for the penetration equation are hardly found in the literature. Therefore, in this paper, the penetration equation is derived using the following steps: (1) Setting up a numerical analysis model and proving it with experimental data, and (2) determining the constants of the penetration equations for various target materials and impact conditions using the numerical analysis model. This procedure can be used to predict penetration when there are no sufficient penetration experimental data for a given material and impact conditions. In this paper, ANSYS Explicit Dynamics was used for creating the simulated penetration data to estimate the parameters of the penetration equation. The penetration numerical analysis was performed for a high-velocity collision between a 7.62 mm AP (armor piercing) bullet and the targets, which include RHA (rolled homogeneous armor) steel and 7075 aluminum. As a result, the error rate between the results of the numerical analysis and penetration experiments is approximately 5 %, which verifies the accuracy of the numerical analysis. The constants of the penetration equation for RHA steel and 7075 aluminum were determined using the numerical analysis model. In vulnerability analyses, penetration equation with the constant that was identified using our methodology can replace the numerical penetration analysis, which requires excessive calculation time.