基于接触理论的弹体偏航机理

为了从本质上揭示弹体偏航作用机理,在已有弹塑性接触模型的基础上,运用接触理论和撞击理论,推导了接触刚度和恢复系数,建立了弹体与异形体弹塑性碰撞的宏观本构关系。进一步导出了弹体与异形体碰撞的攻角和角速度表达式,计算分析了弹头与异形体曲率半径比、弹体命中速度及入射角等因素对弹体攻角和角速度的影响规律。结果表明,异形体曲率半径越大,弹体攻角和角速度越大;弹体攻角随速度增大而减小,而角速度随速度增大而增大。

Yawing mechanism of projectiles based on contact theory

In order to explain the yawing mechanism of projectiles when colliding on abnormal objects,based on former elastic-plastic contact force-displacement model,and the macroscopically constitutional relationship of elastic-plastic collision between the projectile and the abnormal object was obtained.The coefficient of restitution and contact stiffness were derived with the theories of contact mechanics,the approximate formulas for calculating the attack angle and the angle velocity of the projectile when colliding on the abnormal object was expressed in terms of the linear and angular impulse-momentum laws.The effects of the main factors,such as curvature radius ratio of the projectile to the abnormal object,impact stances or velocities of the projectiles,on the effectiveness of inducing projectiles to yaw were calculated and analyzed.The results shown that the yawing effectiveness of the projectile becomes obvious with the enlarging of the size of the abnormal object.The attack angle of the projectile will decrease with the impart velocity increasing while the angle velocity will increase with the impart velocity increasing.