火炮身管锥度对弹丸起始扰动的影响分析

火炮身管设计时,根据强度理论有一段圆锥段,身管圆锥段锥度的大小影响近炮口段身管刚度的大小,刚度大小对于弹丸起始扰动的影响规律值得进行研究。针对这一问题,建立某大口径火炮弹炮耦合全炮动力学有限元模型,计算不同工况下锥度为c=0°、c=0.38°、c=0.73°和c=1.17°时弹丸膛内的运动规律。分析结果表明,对建立的某大口径火炮而言,在保证身管质量、质心不变的前提下,身管锥度越小,即身管近炮口段越粗,身管近炮口段刚度越大,越有利于减小弹丸起始扰动。     

旋转自稳定末敏子弹运动特性分析

为研究某型旋转自稳定末敏子弹运动特性,充分考虑末敏子弹的结构强非对称特点和其初始抛撒条件,引入动不平衡弹体模型,推导超大攻角条件下子弹的空间6自由度弹道方程,计算分析子弹的稳态扫描运动特性。结果表明:子弹体的质量分布非对称和初始抛撒角速度是子弹药实现稳态扫描运动的必要条件;子弹扫描频率只由抛撒角速度ω_(σ0)决定,且和ω_(σ0)正相关;初始俯仰角φ_(a0)≥0°时,扫描角整体呈增大趋势,初始俯仰角φ_(a0)0°时,扫描角整体变化趋势为先减小后增大;扫描面积与配重-全弹质量比、初始俯仰角、初始偏航角和初始角速度呈正相关,与均质圆柱体转动惯量比呈负相关。     

火箭子母弹对行进中炮兵连射击的毁伤概率

炮兵实施机动是提高其生存能力与作战能力的重要手段之一,而从集结地域至待机阵地机动阶段由于距离对方近、暴露时间长,是对方毁伤火力种类最为丰富和威胁最大的阶段.以行进中的自行与牵引炮兵连为研究对象,分析了该阶段火箭子母弹攻击时的毁伤概率,计算了相应条件下的毁伤概率值,描述了毁伤概率与航路角、行进速度之间的基本关系和变化规律.     

采用动网格技术的弹托分离仿真模型

针对一体化弹丸出炮口后弹托由与弹体接触到绕弹托质心做六自由度运动的过程,提出一种基于弹托分段分离运动并采用动网格技术耦合流体控制方程和六自由度运动方程的弹托分离仿真模型。以尾翼稳定脱壳穿甲弹为例,仿真分析不同马赫数下的弹托分离情况,并探讨弹托和弹体气动系数在分离过程中的变化情况。仿真结果表明:弹托分离马赫数越大,分离轨迹越靠近弹体且分离时间越短,但对地分离横向位移越大。通过与试验数据的对比,验证了所提弹托分离仿真模型的准确性。     

Firm embedding behavior of annular grooved projectiles impacting ductile metal targets

Annular grooved projectiles (AGPs) have drawn ongoing concerns as an advanced penetrator for their excellent anti-rebound capability in impacting metal plates. They could become embedded solidly in the target surface during low-velocity impact. In this investigation, the firm embedding behavior of AGP was observed by impact experiments. Corresponding numerical simulations provided a better understanding of this process. Experimental and numerical results indicated that the firm embedding behavior of AGP was mainly due to the filling-material in the groove rather than the friction between the projectile and target, unlike traditional shape such as conical projectile. According to observation, firm embedding process can generally be subdivided into four stages: initial-cratering stage, groove-filling stage, filling-material failure stage and rebound vibration stage. Moreover, the damage mechanics of target material around crater was obtained through microscopic tests. A comparison of the cross-sectional figures between the experiment and simulation proved that the analysis and the proposed method were reasonable and feasible, which further demonstrated that the firm embedding behavior has application potential in new concept warheads.     

火箭弹防静电作用研究

针对电发火弹药静电放电问题,以某型130 mm火箭弹为例,采用真实静电感度测试系统测试了电火工品在有、无绝缘层时50%的静电点火能量,并在试验程序及数据处理中使用真实静电感度数据处理方法统计了50%静电发火能量的估计值。通过比较发现二者的差值在误差范围内,这表明静电放电研究中可以将弹体所接受的能量视作全部作用于火工品上,绝缘层不吸收静电放电的能量。在电发火弹药的防护中,必须采用静电防护措施杜绝电发火弹药的意外发火。     

基于公理设计理论的某自行炮弹仓结构分析

公理设计在设计过程中提供一种描述设计目标的框架,设计者以这一框架作向导进行产品设计,使设计过程形式化,设计决策易于理解,并对设计的预期质量进行评价;应用公理设计方法对某自行炮全自动弹仓结构进行了分析,并提出了一种基于公理设计理论的某自行炮弹仓部件设计顺序。     

激光末制导炮弹过重力补偿比例导引律的分析

以相对运动方程组为基础,分析了导引律的运动学实质和过重力补偿的信号流图,进而分别对比例导引和基于过重力补偿为常值的过重力补偿比例导引下的弹道进行了对比仿真计算。结果表明,过重力补偿比例导引适用于攻击非机动和机动性不大的目标,落角增大,命中点附近视线偏转和控制过载变大,能够实现对目标的大落角攻顶效应。     

Resistance of grid steel-tube-confined concrete targets against projectile impact: Experimental investigation and analytical engineering model

Steel-tube-confined concrete (STCC) targets are provided with excellent anti-penetration performance over semi-infinite concrete (SIC) targets since the steel tube imposes passive restraint on the in-filled concrete during the penetration process. Grid STCC system with square steel tubes is a potential solution to protective structures. In this paper, experiments of 9-cell grid STCC targets penetrated by 12.7 mm Armor Piercing Projectile (APP) were performed. The influence of side length and thickness of steel tube, steel ratio and impact velocity on anti-penetration performance were taken into account. Additionally, single-cell square STCC targets were also designed and tested for comparison with the 9-cell grid STCC targets. Damage modes and parameters of the tested targets were measured and discussed. Moreover, the stiffness of radial confinement of grid STCC targets is achieved according to the elastic solution of infinite cylindrical shell in Winkler medium. Furthermore, the penetration resistance and depth of penetration (DOP) for grid STCC targets are obtained on the basis of the dynamic finite spherical cavity-expansion (FSCE) models including radial confinement effect. It is shown that the 9-cell grid STCC targets with optimal dimension match of thickness and side length of steel tube can reduce the DOP by about 17 % and 23 % in comparison with the SIC targets and single-cell square STCC targets, respectively, due to both the confinement of square steel tube to concrete in the impacted cell and the additional confinement of the surrounding cells to the impacted cell; the penetration resistance and DOP of the grid and cellular STCC targets with similar steel ratio is close, and thus the grid STCC targets with simpler manufacturing process and excellent in-plane expandability are preferred in engineering practice; moreover, the predicted results of DOP model based on the FSCE models agree well with the tested results with the maximum disparity less than 12 % and the proposed model is more applicable to the grid and cellular STCC targets with high radial confinement.     

线膛火炮身管剩余寿命的神经网络模型研究

利用前馈式人工神经网络方法,根据试验数据,建立了某火炮身管剩余寿命(RL)模型;并用该模型研究了各特征截面内径改变量对弹丸初速改变量的影响,以及弹丸初速改变量与总内径改变量间的关系。