# Analysis of Strength Effects on the Dynamic Response of a Shaped-Charge Under Lateral Disturbances
## 4 Dynamic Impact Test of Shaped-Charge Jet
### Numerical Simulation and Validity Verification of Prediction Model  
It was estimated that the moving speed of the shaped-charge was 275.86 m/s. The target plate material was 35 CrMnSiA, and the shaped jet broke through two layers of homogeneous steel targets and finally accumulated on the third-layer target plate, leaving no obvious trace on the back of the third-layer target plate. The total impact depth was 120 mm. In the numerical simulation under the corresponding working conditions, the jet also penetrated the three-layer target plate, and the value for impact depth was in good agreement with that found here. The results of the numerical simulation and the experimental comparison of the jet dynamic impact are shown in Figure 10.  
It can be seen from Figure 10 that the penetration failure modes and effects on both the incident surface and the back surface of each layer of target plate were similar between in the numerical simulation and dynamic test. On the first layer of the target, due to the presence of lateral disturbance velocity, there are obvious cutting marks on the surface of the target, which is quite different from the shape created by the jet penetrating the hole under static conditions. On the surface of the first layer of target plate, the length width ratio of the hole opened by the jet is about 1:1.64; on the second and third target layers, the length: width ratios of the holes after jet penetration are about 1.1 and 1.08; these values are close to 1:1, indicating that the influence of lateral disturbance is mainly significant in the area near the surface of the target. Inside the hole where the jet penetrates, it can be seen that a large number of shaped-charge jets become attached to the walls of the hole under the influence of transverse disturbance and fail to flow into the bottom of the hole, thus weakening the penetration depth of the jet. Figure 9: Photograph of a typical jet dynamic impact test. Through the combination of the results of the numerical simulation and the experiment, it can be seen that the relative error in the perforation aperture between the two is not more than 7%. The jet penetrated two layers of 60 mm homogeneous target plates and accumulated on the third layer of the target plates. The dynamic penetration depth of the jet obtained by numerical simulation also shows good agreement with the experimental results. The difference between the results of the numerical simulation and the experimental results is mainly due to the fact that in the actual test, the shaped charge is driven by the rocket, and there is a certain degree of uncertainty due to the influence of air resistance and overload. The performance of the shaped charge is greatly affected by many factors during production, processing and assembly, leading to inherent variability [29]. Therefore, after comprehensive evaluation and analysis, the numerical simulation results are considered close to the experimental results, so the simulation can be considered to effectively represent the actual situation. In order to further analyze the effectiveness of the predictive model, in the dynamic test, three groups and six groups of rocket motors were used to push the shaped charge, and the target materials were used to obtain the dynamic impact depth of the shaped jet at different relative speeds. The flight speeds are 125.6 m/s and 285.4 m/s, as recorded and measured by high-speed photography. [PERSON] et al. [30] showed that when the lateral disturbance velocity is greater than 50 m/s, the influence of lateral action is reflected in the jet's penetration. Therefore, in the experiment, we assigned a lateral velocity of approximately 125-285 m/s to the energy-gathering charge component, which is sufficient to reflect the dynamic penetration of the jet under lateral disturbance. Due to the long preparation cycle required for rocket pulleys, shaped charges, and rocket engines, only one successful test has been conducted for each configuration so far.