Characteristics structure analysis on debris cloud in the hypervelocity impact of disk projectile on thin plate

In this paper, the gauge points setting is introduced in the SPH simulation to analyze the debris cloud structure generated by the hypervelocity impact of disk projectile on thin plate. Compared with the experiments, more detailed information of the debris cloud structure can be classified from the numerical simulation. However, due to the solitary dispersion and overlap display of the particles in the SPH simulation, accurate comparison between numerical and experimental results is difficult to be performed. To track the velocity and spatial distribution of the particles in the debris cloud induced from disk and plate, gauge points are locally set in the single-layer profile in the SPH model. By analyzing the gauge points’ spatial coordinate and velocity, the location and velocity of characteristic points in the debris cloud are determined. The boundary of debris cloud is achieved, as well as the fragments distribution outside the main structure of debris cloud.     

商业建筑火灾荷载调查和统计分析

火灾荷载是判断建筑室内火灾危险程度的依据，也是性能化防火设计中设计火灾的重要内容。调查了在廊坊、长治、郑州及天津四个城市的零售类商业店铺火灾荷载情况，调查的对象包括快餐店、服装店、鞋店等商业零售店铺。针对这些店铺常见的可燃物形式，确定了5种可燃物，分析它们在总火灾荷栽中的比重。共计调查了117家商业店铺，总面积4095m^2，面积最小为2．5m^2，最大为185m^2。这117家店铺的火灾荷载密度与样本数之间具有对数正态分布，调查得到的所有店铺火灾荷载密度平均值为1230MJ／m^2，最大值6813．4MJ／m^2，最小值92MJ／m^2，标准偏差1240．5MJ／m^2。     

关于小尺寸装药用炸药薄膜的研究

利用真空蒸镀技术对太安炸药薄膜及其在小尺寸装药上的应用进行了研究。实验表明利用真空蒸镀技术可以研制出性能优良的炸药薄膜 ;红外光谱分析证明太安在蒸镀前后没有发生质的变化 ;扫描电镜分析得出了太安薄膜的微观结构 ;太安炸药薄膜在小尺寸装药上的应用表明了该装药具有可靠的传爆功能。     

Experimental research on the instability propagation characteristics of liquid kerosene rotating detonation wave

In order to study the instability propagation characteristics of the liquid kerosene rotating detonation wave (RDW), a series of experimental tests were carried out on the rotating detonation combustor (RDC) with air-heater. The fuel and oxidizer are room-temperature liquid kerosene and preheated oxygen-enriched air, respectively. The experimental tests keep the equivalence ratio of 0.81 and the oxygen mass fraction of 35% unchanged, and the total mass flow rate is maintained at about 1000 g/s, changing the total temperature of the oxygen-enriched air from 620 K to 860 K. Three different types of instability were observed in the experiments: temporal and spatial instability, mode transition and re-initiation. The interaction between RDW and supply plenum may be the main reason for the fluctuations of detonation wave velocity and pressure peaks with time. Moreover, the inconsistent mixing of fuel and oxidizer at different circumferential positions is related to RDW oscillate spatially. The phenomenon of single-double-single wave transition is analyzed. During the transition, the initial RDW weakens until disappears, and the compression wave strengthens until it becomes a new RDW and propagates steadily. The increased deflagration between the detonation products and the fresh gas layer caused by excessively high temperature is one of the reasons for the RDC quenching and re-initiation.     

成本分担定价方式的装备采购博弈研究

承包商的努力程度直接决定了装备的制造成本。为有效激励承包商降低装备制造成本，提高装备采购效益，基于里昂惕夫劳资博弈模型建立了成本分担定价方式的装备采购博弈模型。并在承包商边际效用非线性和定价方式多变量的假设基础上，分别对价格、成本、承包商努力程度和承包商效用之间的关系进行了研究，对原模型进行了拓展，为定价方式中参数的确定提供了量化方法。     

箭（弹）级间螺栓法兰连接结构准静载失效实验与数值仿真研究

基于火箭(导弹)级间螺栓法兰连接结构,简化设计并制作了一组原理性实验件,设计准静载加载实验测试系统,进行了两次准静载失效实验,并利用ABAQUS软件建立对应的有限元模型。实验中设计了螺栓力响应信号采集传感器,获得了螺栓力响应数据、加载力与加载位移等多组关键数据。根据实验效果和实测数据,分析了连接结构在准静载荷载作用下的失效机理,并对比验证了有限元模型数值模拟效果和精度与实验吻合较好。研究结论可为箭(弹)级间连接结构承载能力和失效实验设计提供参考。     

通用装备机械部件试验系统设计

针对现有修后试验设备的不足,以柔性装卡、自动控制为设计思想,介绍了通用装备机械部件试验系统的设计过程。该试验系统采用1套柔性支架可完成多种车型、多种机械部件的试验,实现了机械部件操纵的集中控制,提高了试验系统的安全性。     

谈地下建筑火灾的特点及预防措施

结合火灾案例和实验数据 ,分析地下建筑火灾特点 ,并有针对性的提出预防火灾的对策     

燃气射流引起的火箭发射系统振动特性分析

以火箭发射系统为研究对象,对其56°射角工况下发射过程中的振动特性进行分析。创新点在于确定发射过程中动态载荷的加载方法,即首先根据发射系统有限元分析结果确定迎气面上试验测量点的具体位置,然后测得燃气射流冲击压强随时间变化的数值,并对试验测得数据进行处理,最后推导冲击压力对于径向距离的直线公式。所采用的冲击压强分析方法为研究其他武器系统受燃气射流冲击的影响提供了重要的指导意义。     

基层战士现实思想行为变化的特点及解决思路

在市场经济形势下，战士的思想出现了前所未有的新变化，市场经济的观念正在深入人心，但遇事心理承受能力弱，思想波动大，“两极性”比较明显。战士成份的变化，势必引起基层战士的思想行为较之过去呈现出极其复杂的变化。要有效解决战士的现实思想问题，必须遵循规律，增强思想工作的预见性、针对性和创造性；结合战士实际，突出思想工作重点，形成科学高效的思想政治工作机制。