典型线性火工分离装置作用过程数值模拟及试验研究

针对目前线性火工分离装置的优化设计主要依靠试验验证,成本高且设计优化迭代慢的问题,采用任意拉格朗日-欧拉方法建立典型线性火工分离装置的数值模型。通过火工分离试验和光子多普勒测速试验对上述数值模型进行验证,发现该数值模型具有较好的精度。使用该模型研究上述火工分离装置分离瞬态过程的力学机理,并定量分析多种因素对分离装置重点部位等效塑性应变等关键特征量的影响。研究发现,芯药线密度、分离板削弱槽底部的圆角半径对分离装置的作用过程有重大影响。此外,保护罩材质、削弱槽开口角度、分离板槽结构尺寸等因素对分离过程也有一定影响,但其影响相对较小。研究结果可以为典型线性火工分离装置的优化设计提供基础。     

Data-driven prediction of plate velocities and plate deformation of explosive reactive armor

Explosive reactive armor (ERA) is currently being actively developed as a protective system for mobile devices against ballistic threats such as kinetic energy penetrators and shaped-charge jets. Considering mobility, the aim is to design a protection system with a minimal amount of required mass. The efficiency of an ERA is sensitive to the impact position and the timing of the detonation. Therefore, different designs have to be tested for several impact scenarios to identify the best design. Since analytical models are not predicting the behavior of the ERA accurately enough and experiments, as well as numerical simulations, are too time-consuming, a data-driven model to estimate the displacements and deformation of plates of an ERA system is proposed here. The ground truth for the artificial neural network (ANN) is numerical simulation results that are validated with experiments. The ANN approximates the plate positions for different materials, plate sizes, and detonation point positions with sufficient accuracy in real-time. In a future investigation, the results from the model can be used to estimate the interaction of the ERA with a given threat. Then, a measure for the effectiveness of an ERA can be calculated. Finally, an optimal ERA can be designed and analyzed for any possible impact scenario in negligible time.     

Microcrack- and microvoid-related impact damage and ignition responses for HMX-based polymer-bonded explosives at high temperature

Investigating the damage and ignition behaviors of polymer-bonded explosive (PBX) under a coupled impact and high-temperature loading condition is required for the safe use of charged PBXs. An improved combined microcrack and microvoid model (CMM) was developed for better describing the thermal effects of deformation, damage, and ignition responses of PBXs. The main features of the model under typical dynamic loadings (i.e. uniaxial tension and compression, and lateral confinement) at different initial temperature were first studied. And then the effects of temperature on impact-shear sensitivity of HMX-based PBXs were investigated. The results showed that the ignition threshold velocity of shear-crack hotspots exhibits an increase from 260 to 270 to 315–325 m/s when initial temperature increases from 301 to 348 K; and then the threshold velocity decreases to 290–300 m/s with the initial temperature continually increasing to 378 K. The predicted ignition threshold velocity level of the explosives under coupled impact and high temperature loading conditions were consistent with the experimental data.     

小子样条件下战斗部爆炸仿真数据可信性分析

高效毁伤战斗部试验次数受到严格控制,如何在小子样条件下分析仿真数据的可信性非常有必要。通过均匀试验得到了战斗部在地下目标腔室内部爆炸某点冲击波最大超压峰值,利用normplot及Lilliefors函数分析了仿真数据的分布特征,而后在已有检验方法的基础上,结合顺序统计量和均匀分布的特点提出了一种新的相容性验证思路。研究表明:该方法不受样本容量的限制,利用MATLAB程序编程可以快速判断仿真数据的可信性。     

基于虚拟现实技术的手榴弹投掷安全施训研究

分析了目前手榴弹投掷训练存在的一些问题和研究方法,模拟仿真了基于虚拟现实技术、N-vision平台、3dsMax以及JACK建立的手榴弹实弹投掷场景,再现优秀训练者的技术动作和细微环节、教练员的意图,采用交互漫游,增强了沉浸感,从而提高训练质量,降低安全隐患风险。     

C~4ISR系统结构时效性的仿真评估

时效性是评价C4ISR系统结构优劣的重要标准。为了支撑C4ISR系统结构的分析评估与优化设计,提出了系统结构时效性的评估指标体系和指标评估模型,基于Agent建模方法建立了情报获取、情报处理、决策控制和响应执行等系统结构单元的仿真模型,设计并实现了C4ISR系统结构仿真评估软件。开展了三类仿真实验,分析了影响系统结构时效性的因素,比较了不同类型系统结构的优劣,验证了此方法的有效性。     

不同类型双层玻璃幕墙火灾烟气流动特性对比研究

采用大涡模拟方法研究整体式、走廊式和竖井式三类常用双层玻璃幕墙的火灾烟气流动特性。结果表明,整体式双层玻璃幕墙内的烟气在竖直方向上的蔓延速度很快,但空腔内烟气温度相对较低,约为180℃;走廊式双层玻璃幕墙可以将火灾烟气完全限制在着火楼层的玻璃幕墙空腔内,但空腔内最高温度高达270℃;竖井式双层玻璃幕墙不能完全阻止烟气向其他楼层玻璃幕墙空腔内的蔓延,但与整体式双层玻璃幕墙相比,进入其他楼层的烟气量明显减少,玻璃幕墙空腔内的最高温度介于上述两种双层玻璃幕墙空腔内最高温度值之间。在实际应用中,应充分考虑不同类型双层玻璃幕墙的消防问题,并有针对性的采取防护措施,降低其火灾危险性。     

以性能为基础的某大型高架仓库消防安全评估

高架仓库空间大、物品堆积密集,火灾危险性大,并且高架仓库设计朝着大面积、大空间的方向发展,当前的防火设计规范已不能满足现代高架仓库的消防安全设计。以某高架仓库的消防设计为例,分析其火灾危险性,提出了以性能为基础的消防设计评估方法,结合该仓库的具体情况进行火灾场景设计。火灾烟气流动模拟和人员疏散模拟结果表明：在消防设施正常启动的条件下,仓库现有的安全措施能够保证火灾时人员的安全疏散。     

运动场馆火灾烟气蔓延规律数值模拟研究

运动场馆规模大、人员密集、功能复杂、用电负荷大、配电线路多、火灾荷载大,一旦发生火灾可能导致群死群伤恶性事故的发生。研究运动场馆火灾情况下烟气变化规律,能够更好的指导消防安全设计。以某运动场馆为例,应用火灾模拟软件对其火灾情况下烟气蔓延过程进行数值模拟研究,分析了常见自然排烟方式对烟气层的高度、温度、氧气浓度、一氧化碳浓度变化的影响,从而为运动场馆防排烟设计提供依据。     

单脉冲雷达导引头角度跟踪环路半实物仿真

单脉冲雷达导引头具有全天候的自动搜捕及跟踪能力,对作战平台的威胁极大,也是平台自卫式干扰的重点。根据平台自卫式干扰效果仿真试验的需求,以单脉冲雷达导引头半实物仿真为立足点,重点介绍了比幅和差单脉冲雷达导引头角度跟踪环路半实物仿真工程实现的关键技术,最后结合具体试验对单脉冲雷达导引头角度跟踪环路性能进行了验证分析。