Resistance during Cratering for Projectile Penetrating into Concrete Target
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摘要: 为了研究弹体侵彻开坑过程中弹头表面阻力,采用应力波表层损伤理论分析了混凝土开坑区的侵彻特性,并在应力波反射形成层裂的基础上解释了靶面成坑机理,建立了计算开坑区弹头表面阻力的新模型,通过数值仿真和实验方法对新模型进行验证。结果表明:数值模拟和实验与新模型的计算结果吻合较好,开坑过程中弹体表面阻力与速度和弹体头部形状有关。新模型能够较好地描述开坑深度与速度的关系,适用于弹体侵彻混凝土靶的阻力计算,克服了Forrestal半经验法的不足。Abstract: In order to explore an expression formula for the stress undergone by the nose of the projectile during cratering in the process of penetration, penetration performance in the surface layer of the concrete target was analyzed using the stress wave damage theory.The crater-forming mechanism was explained based on the theory of stress wave obliquely reflection, and the expression formula was established for the stress endured by the nose of the projectile.By conducting numerical simulations and experiments, the depths of the carter were measured to verify the engineering model.The results indicate that the resistance is related to the velocity and the nose shape of the projectiles.A comparison of the theoretical and numerical results with the experimental data demonstrates an improved agreement between them.The new model, which is capable of overcoming the shortcomings of the Forrestal method, successfully describes the relation between the penetration velocity and the crater depth and can be applied to the calculation of the resistance for projectiles penetrating into concrete targets.
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Key words:
- impact dynamics /
- penetration resistance /
- crater zone /
- stress wave /
- damage theory /
- slabbing
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表 1 混凝土材料参数
Table 1. Concrete material parameters
ρ/(g/cm3) G/(GPa) fc/(GPa) A1 B1 D1 D2 εfmin p1/(GPa) N1 T/(MPa) C1 2.4 14.86 40 0.79 1.6 0.04 1 0.01 0.8 0.61 4 0.007 表 2 开坑区的几何参数
Table 2. Geometrical parameters of crater zone
Projectile Velocity/(m/s) Crater depth/(mm) Crater size/(cm2) P3 1039 38.9 15.0×18.0 P3 925 31.4 13.5×16.3 P3 805 27.5 11.5×14.5 P4 1038 41.8 17.8×19.1 P4 920 35.2 15.5×18.0 P4 803 28.7 13.0×16.0 -
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