某型自行加榴炮抽筒过程动力学分析

分析了某型自行加榴炮钢质药筒不抽筒产生的原因,简述了火炮抽筒机构改进的措施,建立了抽筒过程的动力学方程,分别对四种方案进行了计算。     

提高焊接药筒焊缝质量途径的探讨

焊接钢质药筒是一种不需要大型压力设备,制作方法比较简单的钢质药筒。保证焊接钢质药筒焊缝质量是药筒强度性能的要求。而药筒环焊缝热裂纹的产生严重影响药筒的强度。因而就焊接钢质药筒环焊缝产生的原因及如何提高焊缝质量,确保药筒在射击时不发生火药气体烧蚀火炮药室等质量问题作了一些探讨。     

焊接钢质药筒与引伸药筒内弹道设计一致性研究

装备内弹道的一致性对其性能影响较大。经过长期对多个弹种用药筒的设计、使用和考核,发现用药筒在膛内容积一致性来进行弹道一致性设计比较适用和相对准确,同时发现挤进压力为P_0时的真实容积对内弹道一致性影响较大。此外焊接钢质药筒的内弹道一致性不仅达到了引伸药筒的要求,而且在或然误差和内弹道稳定性方面优于引伸药筒。     

亚温正火在焊接钢质药筒筒底锻造中的应用分析

焊接钢质药筒是由筒底和筒体两部分经环焊而成。其中筒底是由35~#热轧圆钢通过锻造成形、粗加工、热处理、精加工而成。在022产品靶场试验中,曾两次出现药筒底缘局部拉裂现象,经查找,原因在于筒底锻造过程中正火温度过高、晶粒粗大,组织性能恶化所致。     

火炮抽筒故障机理研究

针对某自行反坦克炮射击后,抽筒时出现药筒钢底座底缘与圆柱部断裂现象这一抽筒故障,分析计算该火炮正常抽筒所需的理论抽筒力和半自动开闩机构所能提供的实际抽筒力,由此定量分析该故障的主要原因,并提出火炮实弹射击预防抽筒故障的具体措施,对半自动开闩结构设计与改进、部队装备训练与射击具有一定指导和参考价值．     

某焊接钢质药筒口部撕裂原因浅析

一、问题的提出某焊接钢质药筒在我厂进行减装药结构试验时,药筒在镗口部位撕裂(见图1),其断裂部位已射出火炮膛外。在我厂多年焊接钢质药筒的试制、生产过程中,虽然也发生过开裂现象,但类似这次的撕裂情况,还从未遇到过,在钢质药筒史上也是极为罕见的。本文就此作一简要分析。     

钢质药筒根部裂纹失效分析

根据钢质药筒成形工艺过程和金属流线的分布特征,分析了裂纹的产生原因,提出了改进措施。     

焊接钢质药筒环焊缝的超声自动检测

焊接钢质药筒环焊缝超声自动检测是超声检测与计算机技术相结合,并增加了多通道输入—单通道输出转换适配技术,从而实现对焊缝疵病的定性、定量、定位的自动检测的系统。     

埋头弹火炮及其弹药技术

埋头弹(Cased Telescoped Ammunition,CTA)也称嵌入式弹药或套筒式弹药。它与常规炮弹的区别是:常规炮弹的弹体呈流线形,弹丸装在发射药筒的前端。弹丸尾部与药筒口部相连接;而埋头弹的弹体呈圆柱形(如同易拉罐形状),弹丸埋在药筒内部,其后部及周围装填发射药。埋头弹通常采用两级点火。底火被击发后,辅助发射药燃烧并将弹丸推离药筒、推入炮膛;弹     

125mm坦克炮炮闩抽筒装置故障仿真分析

针对125 mm坦克炮炮闩抽筒装置的常见故障和失效模式,建立了125mm坦克炮炮闩抽筒装置上抽筒子的三维数字模型,并进行了动力学仿真;利用多体动力学仿真方法对抽筒装置的典型故障机理和易损部位的损坏程度进行了分析,得到了其损坏的原因和改良方法;为研究抽筒装置的故障机理提供理论依据,为探索、改进炮闩抽筒装置结构、提高其可靠性开辟了一条新的道路。     

Experiment and simulation of launching process of a small-diameter steel cartridge case

In order to explore the rules of the deformation force during the launching of a small-diameter steel cartridge, the semi-closed bomb test method is used to test the greatest strains on chamber outer wall under the different chamber pressures. The pressure curves of cartridge chamber are measured in experiment, and the tensile test data of cartridge are loaded into the numerical calculation to compare with the experimental data. The conclusion was obtained that the calculated results match better with the experimental results by considering strain rate bilinear kinematic hardening material constitutive model. The forces on the various parts of the cartridge during launching and their deformation rules are achieved, in which the equivalent plastic strain decreases and the cylinder ring withstands the maximum equivalent stress when the cartridge case clings to the bore from the mouth to the bottom.     

Theoretical and numerical investigations on the headspace of cartridge cases considering axial deformation and movement

The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon, and influences the reliability and security of the weapon. Accordingly, theoretical and numerical studies were conducted to analyze the dynamic response of cartridge cases during internal impact considering the initial radial clearances between the cartridge case and chamber. A theoretical model was proposed to predict the cartridge case headspace considering both the deformation and movement of the cartridge case and confirmed by the results of nonlinear finite element simulations. The differences between the results of the conventional static model and the dynamic model were then comprehensively evaluated. The effects of the angle between the cartridge and chamber, the cartridge case material, and the internal impact pressure on the predicted headspace value were also analyzed. The dynamic response of the cartridge case predicted by the dynamic model was more accurate than that predicted by the conventional static model. The internal impact pressure, pressure change rate, and cartridge material were all found to affect the predicted headspace.     

Effects of module number and firing condition on charge thermal safety in gun chamber

Thermal safety of modular charge which is fed into and retained in the chamber after gun fires consecutively is first investigated with cook-off method.A two-dimensional cook-off model of modular charge in gun chamber is established and the cook-off process of modular charge in gun chamber is numerically simulated.Then the effects of module number and firing condition on charge thermal safety are evaluated by researching the cook-off response characteristics of modules.The results show that,under conditions of different module numbers the cook-off responses all occur on the module closest to the boundary of missile,and the single-base propellants located at the inner surface of cartridge ignite first.When the number of loaded module changes from 1 to 6,the cook-off response temperatures vary little,only in a small range of 478.1 K-482.4 K.The cook-off response times decrease logarithmically in the range of 211.2 s-166.7 s with the increasing length of residual air gap in gun chamber.The simulation results are well matched with the experimental data.Furthermore,different firing conditions have great influence on the cook-off response time,minor influence on the initial response position and little in-fluence on the response temperature.Under the three conditions of consecutive 32 launches with 5 rounds/min,43 launches with 1 round/min,and 41 launches with different firing frequencies,the cook-off response temperatures are 479.2 K,481.1 K and 479.9 K respectively and the response times are 709.2 s,211.2 s and 214.4 s respectively.The response position is near the middle area of the inner cartridge surface in the former condition and near the right area in the latter two conditions.     

大口径火炮制退机内腔压力测试技术

从火炮反后座装置的特殊结构及测试技术两方面详细分析、总结了我国几种大口径火炮在内腔压力测试时出现不正常现象的原因,并从传感器的机械度、传感器的封装技术、传感器的绝热处理、传感器的频响和排气工装等几个方面改进内腔压力测试的技术工艺方法,并用改进后的方法对155-2型火炮的内腔压力进行了试验,结果表明其工艺方法可准确地测试出内腔压力曲线,从而解决了多年来火炮后座阻力测试技术中存在的关键问题。     

坦克射击过程中炮膛内火药气体温度计算

坦克射击后出现炮膛内壁烧蚀及身管温度上升等问题，其首要因素为火药爆炸燃烧所产生的高温气体。应用内弹道零维模型，以空间平均热力学参数描述坦克射击过程中炮膛内弹道状态，采用四阶龙格一库塔法求解内弹道常微分方程组，计算出内弹道时期火药气体的压力、流速和温度等随时间的变化规律。应用指数函数拟合出后效期炮膛内火药气体温度公式，最后得到坦克整个射击过程中炮膛内火药气体温度的变化规律。通过计算结果与试验数据的对比，验证了计算结果的合理性。此计算结果可为坦克炮身管的烧蚀、热状况及红外辐射特性的研究提供理论依据。     

基于最小二乘支持向量机的坦克炮身管剩余寿命预测方法

针对高膛压坦克炮身管剩余寿命预测的难题,结合坦克实弹射击试验数据量少和非线性的特点,基于最小二乘支持向量机构建了坦克炮身管剩余寿命预测模型,给出了模型参数的选取方法,并以某型坦克炮射击试验为基础,对坦克炮身管剩余寿命预测模型进行了验证。结果表明:该模型预测坦克炮身管剩余寿命效果良好。     

Experimental investigation of a cook-off temperature in a hot barrel

The experimental investigations of the effect of contact time/temperature on initiating the cook-off using 7.62 mm calibre cartridge cases (CC) were conducted previously. These cartridges were filled with commercial off-the-shelf (COTS) double based (DB) propellant (Bulls Eye) and were loaded in a hot chamber. The thermal explosion temperature is of great significance to both weapon designers and safety inspectors as it provides the operational limit and safe operating temperature. For CC under test, it was found that the cook-off temperatures of this propellant were encountered with the heat transfer profile of the simulated gun barrel between 151.4 °C and 153.4 °C, with a reaction occurring in less than 300 s after the round was chambered. Usefully, each experiment was found to be consistent and repeatable.     

舰炮对海上集群小目标射击的毁伤概率

海上集群小目标是水面舰艇面临的主要威胁之一。以单管大口径舰炮对海上集群小目标射击作为研究对象,对集群目标进行了等效处理,分析了弹种、引信和装药的选择以及效力射中的表尺分配问题,提出多表尺效力射方法,利用该方法对海上集群小目标射击的毁伤概率进行了分析。结果表明,采用该方法并使用空炸榴弹或杀伤爆破弹,可有效破坏敌运输工具,杀伤其有生力量。     

Strain concentration caused by the closed end contributes to cartridge case failure at the bottom

Ruptures at the bottom of cartridges are a common cause of failure of ammunitions, which directly threatens the safety of weapons and shooters. Based on plastic tube theory, this study analyses the radial and axial deformation of a cartridge, considering the radial constraint of the closed end at the bottom of the cartridge. Owing to the influence of the closed end, the bottom of a cartridge does not establish complete contact with the chamber. Owing to strain concentration in the non-contact area, this area is more amenable to the occurrence of cartridge rupture. This theory predicts the location of the fracture more accurately than the traditional theory. The maximum axial deformation of a cartridge comprises bending and friction deformation. The maximum strain at the bottom of the cartridge increased by 135% owing to the introduction of bending strain caused by the closed end. The strain distribution of a cartridge was measured using digital image correlation technology, and the measured result was consistent with the predicted results of the bending deformation theory and rupture case. The effects of wall thickness, radial clearance, friction coefficient, and axial clearance on the axial deformation of the cylinder were studied. Increasing the wall thickness and reducing radial clearance were found to reduce bending deformation; furthermore, lubrication and reduction in axial clearance reduce frictional deformation, which in turn reduce cartridge rupture.