基于ADAMS的击针磨损量与击发可靠性分析

本文采用可靠性原理和现代模拟方法，结合项目工程研究实践，依据某转管炮击针磨损率和击发可靠性关系相关理论，构建了可靠性仿真模型。利用ADAMS参数化仿真模块，建立转管炮击针磨损量与击发可靠性虚拟样机模型，通过数据迭代及优化仿真结果进行对比分析，得出在现有弹簧刚度条件下，击针磨损量不大于0.65mm时，击针对弹药底火可实现可靠击发。该仿真方法及分析结果对研究转管武器击针磨损量与击发可靠性具有一定的参考价值。     

机械击发装置撞击力学分析

通过推导能量转化公式得到机械击发装置工作过程中击针对底火的撞击速度和撞击能量数值,在此基础上利用ALGOR软件对撞击过程进行有限元分析。分析结果表明将公式计算与数值仿真相结合是机械击发装置结构设计的有效途径。     

基于故障树的机械击发故障仿真分析

以某火炮出现炮弹留膛故障为背景,对可能引起该故障的击发机构进行故障分析.建立了机械击发机构的故障树,并对故障树进行了定性分析,然后按照故障树对故障模式进行了逐一的排查,对排查过程中尚不能确定的可能引起击发机构故障的两种故障模式:击发能量不足和磨损导致击针凸出量不足,应用ADAMS软件进行了故障仿真分析.通过仿真分析发现这两种故障模式下击发能量和击针凸出量均满足可靠击发的条件,因此排除了机械击发故障导致炮弹留膛的可能性,需要进一步对炮弹进行相应的故障分析.     

81枪族击发机可靠性分析及结构改进

可靠性是评价武器系统性能优劣的重要指标之一,通过对81枪族击发机的可靠性进行综合分析,提出了机构工作安全保险的概念,并认为81枪族击发机在结构设计上缺少机构工作安全保险中的零件位置不正确保险,存在事故隐患。针对这一情况,提出了对击发机结构的改进方案,并应用AUOTCAD软件进行计算机模拟,得出改进后的扳机限制突笋高度值,通过试验验证,改进后的击发机工作可靠性提高,且不影响枪械其它各动作的顺利进行。     

一种炮弹尾翼全跳动误差值的自动检测装置

在炮弹装配生产过程中,弹体和尾翼组装成一体称为全弹装配。弹体的圆柱部分称为弹体定心部,尾翼翼片下缘所形成的直径称为尾翼定心部,并与弹体定心部一起构成导引部,使弹丸在膛内定心。为减少炮弹装填时对炮膛的磨损和保证底火与击针对正,并使炮     

核电站高能管道甩击防护中的能量及力学分析

高能管道是核电站中重要管道系统,当发生破裂甩击时危害性极大,因此需要对高能管道进行甩击防护。基于动力分析有限元程序LS-DYNA建立了管道-限制件系统模型,通过调取系统能量、位移和甩击力时程曲线对管道甩击过程进行分析,并将计算结果与试验数据进行验证;针对甩击过程的能量和应力进行计算,并对支架防甩击性能的影响因素进行详细分析。结果表明,仿真计算具有足够的准确性,支架吸能性能和受力状况可以通过支架形式、结构以及材料参数进行调控。该研究结果对防甩击支架设计及优化具有一定参考价值。     

考虑Kriging模型的击针疲劳强度可靠性分析

击针是枪械的重要部分,随着射击次数的增加,击针可能产生断裂,影响正常使用。疲劳断裂是击针失效的主要因素,而采用随机有限元模型的击针疲劳可靠性分析计算量大,为此提出了一种考虑疲劳损伤退化过程的Kriging模型分析方法。首先利用有限元对部件进行应力应变分析,产生了计算疲劳损伤所需的数据,再由Kriging模型模拟结构应力函数,利用Neuber局部应力应变分析法求出击针的疲劳损伤,最后由Kriging模型结合蒙特卡洛方法模拟抽样随机因素下的单发射击时的损伤大小,拟合了击针疲劳损伤退化量的分布函数,并由此退化数据分析评估了击针的可靠性。结果表明:该方法较为准确且计算量小,更适用于疲劳可靠性问题的快速评估。     

一种引信典型机构的动力学仿真测试方法

针对机械引信以往单纯靠物理试验和计算进行仿真测试的工作模式,击针在引信体内部可靠作用及其戳击火帽能量在整个引信设计中较难测试等问题,为减少加工、试验及人力等成本,提出在机械引信前期设计中,实现引信典型机构——保险及发火机构的动力学仿真测试,为此类机械引信前期设计及后期试验提供了仿真分析方法,提高了引信设计的时效性及多体动力学计算结果的准确性。该方法利用ADAMS,通过确定输入量及参数设置,模拟相关环境力,对机构模型进行选取多种工况的仿真验证,输出所需参数并分析。试验表明,该方法较好地解决了引信瞎火或早炸等故障,取得了较好的试验效果。     

基于ANSYS的气动枪针组件关键参数的研究

利用Pro/E软件对某型号气动钉枪枪针组件进行建模,导入到ANSYS中,进行了非线性接触分析,探讨了枪针组件的关键参数的合理范围,为枪针组件的设计与制造提供了依据。     

某击发机构动力学仿真研究

为了研究击发机构的力学特性,对击发机构零部件进行三维实体建模,考虑拨动子驻栓、发射器推杆和电磁连杆的柔性,利用Hypermesh软件对它们进行模态分析,生成可被动力学分析软件ADAMS调用的模态中性文件,建立击发机构刚柔耦合动力学模型,对击发机构进行了刚柔耦合动力学分析和对击发机构机理分析使用方法与手段,分析结果对于火炮击发机构的设计具有一定的参考价值。     

Validation of piezoelectric measurement system for weapon firing pin percussion energy

Functional reliability of a service firearm is essential. A failure to fire at a critical moment could lead to disastrous consequences. The firing pin of a weapon must hit the primer hard enough to ascertain reliable detonation of the primer which then ignites the powder. Depths of firing pin created indent on an inert primer and on a copper cylinder are the two methods conventionally used to estimate this percussion energy. In this study the copper cylinder method was compared with piezoelectric measurement. It was found out that both systems give reliable readings. Eight pistols of calibre 9 mm were measured. Although the majority of the measured weapons seemed to provide sufficient percussion energy, there were some surprisingly low readings with seemingly perfect weapons. This discrepancy shows the necessity of an industrial standard and of using a reliable percussion energy measurement system for monitoring the condition of service weapons. Further research on firearm and ammunition primer compatibility is required.     

能量法对活塞销力信号的故障诊断

利用Pro/E软件建立单缸发动机参数化模型,导入ADAMS仿真分析不同工况且不同活塞销状态下工作情况,然后对数据进行了基于能量法的分析,得出活塞销故障诊断方法。能量值发生阶跃以及能量处于不稳定状态是活塞销的故障特征之一。     

冲击试验机摆锤的设计与检验

通过对硬质塑料简支梁、悬臂梁冲击试验机以及金属冲击试验机的研究,建立了摆轴轴线至打击中心距离与冲击能量、冲击速度以及摆锤的落角之间的计算公式;以打击点尽量靠近打击中心为目标函数,建立了摆锤优化设计数学模型,并采用FORTRAN语言编程进行了优化设计;     

Magnetic-field-assisted laser percussion drilling

This study explored the feasibility of magnetic-field-assisted laser percussion drilling on highly reflective materials, i.e., Al5052. During laser percussion drilling, the Lorentz force generated by the assisting magnetic field affects the laser-induced plasma. A magnetic field simulation was performed to investigate the field strength of the circular hollow permanent magnet used herein. The influence of the magnetic field and laser radiation energy on the penetration depth and inlet diameter was examined. All experiments were performed in air without additional process gas. It was found that at laser radiation energy of 200 mJ with magnetic field assistance, the penetration depth could be increased by 87.7 % and the inlet diameter could be reduced by 23.7 % as compared with percussion drilling without the applied magnetic field. However, when the laser radiation energy was reduced to 120 mJ, the magnetic field confined the plasma plume; therefore, the penetration depth decreased.     

Design and development of a quick-stop device (QSD)

Quick stop devices (QSDs) are used for collecting samples of chip roots which are representative of the deformation in the primary shear deformation zone, taking place during dynamic cutting conditions. This paper reports on a safe, easy-to-operate and fast-retracting quick-stop device that has been designed, fabricated and tested. It uses a concept thought to be new to this field where stored strain energy is used for retracting the tool: existing QSDs operate on the principle of failure of a pin under shear stress, which is slower compared to the failure of a pin under tensile stress. The proposed device operates on the principle of failure of a tensile pin rather than a shear pin. It permits the collection of chip roots for in depth study of the mechanisms of deformation in the primary and secondary shear deformation zones. The time taken for the withdrawal of the tool from the workpiece has been estimated theoretically as well as experimentally. The chip roots were collected under different cutting conditions.     

The influence of contact geometry on friction and wear characteristics

This paper describes some results of evaluating the influence of contact geometry on tribological characteristics. Friction characteristics obtained for a distributed contact (pin‐on‐disc and block‐on‐ring), a linear concentrated contact (pin and vee‐block and block‐on‐ring) and a point concentrated contact (ball‐on‐disc and three cylinder‐cone) are presented. The wear scars were analysed using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results show different values of friction and wear coefficients for the different types of contact geometry. The paper also assesses the effect of non‐test characteristics, e. g., vibration.     

基于LS-DYNA的电磁冲击器阀芯能量传递效率研究

阐述了电磁冲击器冲击时的能量转换过程,对电磁冲击器阀芯构建了有限元模型,并利用LS-DYNA软件对其冲击过程中阀芯的能量传递效率进行了研究,得出合理的结论,为以后冲击机械的设计开发和优化设计提供了可靠的依据。     

试论滑动副间隙的驱动油液压缸铰接耳的设计

对合有间隙的滑动副的驱动油液压缸进行了分析,得出了不同载荷类型、不同销轴布置方式下的液压缸的受力模型,得出了当作业单元受单向侧向载荷时,液压缸两端铰链的销轴应平行布置,且销轴轴向与载荷方向垂直;当液压缸两瑞销轴轴向与载荷方向不垂直或者作业单元受双向侧向载荷时,应在液压缸销孔与销轴之间安装关节轴承,或者按文中得出的相关公式增大液压缸销孔的公称尺寸.     

截面形状对疏水性微肋阵内减阻特性的影响*

在截面为圆形、菱形和椭圆形微肋阵内涂覆不同性能的疏水性涂层,形成疏水性微肋阵。去离子水在疏水性微肋阵内表面的接触角分别为99.5°、119.5°和151.5°。测试去离水以不同流速流经疏水性试验段流道内压力降和摩擦阻力系数。试验结果表明,在相同的接触角和流量下,圆形微肋阵内压力降最高而椭圆形最低;当接触角为99.5°,雷诺数Re低于600时,椭圆形微肋阵内减阻率要高于菱形和圆形微肋阵,当Re>600时前者要低于后两者。随着接触角的增大,圆形内减阻率要明显高于菱形和椭圆形微肋阵,菱形和椭圆形微肋阵在低Re下较为接近,在高Re下前者的减阻率要高于后者;表面疏水性处理能够显著降低摩擦阻力,同时推迟流动分离和尾流区转捩,因此对于分离较早、压差阻力较大的微肋阵的减阻效果更加明显。