基于变分法原理的侵彻弹体头部形状优化设计

Based on Variation Method for the Shape Optimization of Penetrator Nose Shape

针对刚性弹体侵彻半无限混凝土靶,利用量纲分析方法分析了介质阻力的基本形式,比较了几种经验模型的阻力规律。基于空腔膨胀理论分析了弹头形状对弹体受力的影响,以平滑弹体过载为目标,利用变分法的基本原理分析了不考虑摩擦力影响时弹头形状函数的优化形式,并与几种常用弹头形状函数进行了比较。基于LS-DYNA 3D的数值模拟计算结果显示具有优化函数头部形状的弹体侵彻过载可有效降低,有利于改善弹体受力状态和提高弹体侵彻性能。

The general function of net force on the nose of a rigid projectile normally penetrating semi-infinite target was construed with dimension analysis method, some resistance law in several experience formulae of penetration was compared. By using variational method, we ge： the shape function of a penetrator in planar cross-seetion to minimize the net force, and compare the result with several popular nose geometries. Frictional effects are negligible in this formulation. The simulation result of projectile rigid body acceleration in LS-DYNA 3D indicate that the penetrator with optimal shape suffered the least peak decrease acceleration which means beared the minimum resistance and conduce the maximal penctration depth.