考虑侵蚀效应的卵形弹丸侵彻混凝土介质模型研究

Model of Ogive-nose Projectile Penetrating Concrete Target Considering Effect of Mass Loss and Nose Blunting

建立同时考虑弹丸质量损失和头部钝化的迭代计算模型,在弹体和靶体参数已知的条件下可以预测侵彻深度、质量损失、头部形状变化以及过载等侵彻相关物理量。通过对侵彻实验数据的验证分析,提出了一种考虑混凝土骨料硬度与弹体材料硬度比值的侵蚀修正系数,修正后的模型对侵蚀的计算精度增加明显。在修正后的模型基础上,对常用的Forrestal经验阻力公式中的静态阻力项进行修正,新的静态阻力项更加精确地反映了有侵蚀效应的弹丸侵彻混凝土的静态阻力。实验和模型对比发现:骨料硬度和弹体硬度的比值与弹丸质量损失率呈线性关系。

An iteration model was built by considering both the mass loss and nose blunting effect. By the model, the depth of penetration, mass loss, shape of projectile nose and acceleration can be predicted when the initial condition is given. A correction factor was proposed by considering the hardness of aggregate and projectile material based on the numerical analysis on the penetration experiment. The result calculated by this model is more accurate when the correction factor is introduced. The least squares fitting of static resistance item was conducted through penetration experiment on the basis of the correction model. The commonly used static-item in Forrestal empirical formula was corrected by the fitting method. The new static resistance-item reflects the static resistance of concrete more accurately. Comparison results of experiment and proposal model show that the ratio of aggregate hardness to the hardness of the projectile is linear with the mass-loss-rate during penetration.