Sensitivity analysis and probability modelling of the structural response of a single-layer reticulated dome subjected to an external blast loading

The structural response of a single-layer reticulated dome to external explosions is shaped by many variables, and the associated uncertainties imply non-deterministic results. Existing deterministic methods for predicting the consequences of specific explosions do not account for these uncertainties.Therefore, the impact of the uncertainties associated with these input variables on the structures’ response needs to be studied and quantified. In this study, a parametric uncertainty analysis was ...     

Damage of a large-scale reinforced concrete wall caused by an explosively formed projectile (EFP)

To quickly break through a reinforced concrete wall and meet the damage range requirements of rescuers entering the building, the combined damage characteristics of the reinforced concrete wall caused by EFP penetration and explosion shock wave were studied. Based on LS-DYNA finite element software and RHT model with modified parameters, a 3D large-scale numerical model was established for simulation analysis, and the rationality of the material model parameters and numerical simulation algorith...     

A novel modification method for the dynamic mechanical test using thermomechanical analyzer for composite multi-layered energetic materials

Herein, we present a thermo-mechanical analyzer(TMA) and dynamic mechanical analyzer(DMA) of composite multi-layered gun propellant, focusing on thermal expansion coefficients and dynamic thermomechanical properties. The linear thermal expansion coefficient of the prepared energetic material is determined as approx. 0.1800 × 10^-4-0.2081 × 10^-4K^-1. According to DMA test and dynamic thermomechanical properties, the glass transition temperature is also obtained. The...     

打造军网绿色论坛

BBS是“电子公告系统”的英文缩写,也称为论坛。随着军队院校网络的建设与发展,各个军校都建有自己的BBS,因其交互性强,信息量大,深为众多学员所喜爱,对学员的学习生活有着很大影响。尤其是军校研究生学员,几乎人人拥有电脑,上网很方便。据对某军校研究生网的BBS调查来看,500多名研究生学员绝大部分是该BBS的注册会员,对BBS的参与热情很高。论坛日发帖量一般在600篇以上,最高达1480篇,人均每天至少发帖一篇。军队校园网已经成为学员对军内外信息获取的主要途径,而且随着在校时间的增长,学员对网络的依赖程度也在加大。可见,军校BBS…     

不断加强我军政治优势建设

优势原则是军事斗争最基本、最古老的法则。追求和夺取优势,是任何一支军队进行军事斗争准备和实践的直接目标。拥有了优势,也就拥有了更多赢得战争的砝码。一旦发生战事,就能以优击劣,稳操胜券。中国人民解放军在80年的革命和建设实践中,形成了独特的政治优势。     

Experimental investigation on weak shock wave mitigation characteristics of flexible polyurethane foam and polyurea

In recent years, explosion shock wave has been considered as a signature injury of the current military conflicts. Although strong shock wave is lethal to the human body, weak shock wave can cause many more lasting consequences. To investigate the protection ability and characteristics of flexible materials and structures under weak shock wave loading, the blast wave produced by TNT explosive is loaded on the polyurethane foam with the density of 200.0 kg/m3(F-200) and 400.0 kg/m3(F-400), polyur...     

某型多管火箭炮射击间隔优化研究

为提高某型多管火箭炮火力密度,对其射击间隔进行优化研究。首先,建立某型多管火箭炮刚柔耦合模型,获得定向器管口动态响应,计算火箭弹起始扰动;然后,求解火箭炮外弹道方程,采用数理统计方法得到多管火箭炮密集度估计值;其次,基于Lanczos法对多管火箭炮进行模态分析,结合火箭炮管口动态响应确定新的射击间隔;最后,将新射击间隔输入动力学模型计算,结果表明在不影响射击密集度的基础上,新的射击间隔缩短发射时间21.4%,有效地提高了多管火箭炮火力密度。     

基于FAHP法的多管火箭武器系统效能评估

为了对多管火箭武器系统作战效能进行评估,基于模糊层次分析法理论(FAHP)和熵权理论,建立了多管火箭武器系统作战效能评估的递阶层次分析结构模型.通过性能指标中两两元素相对比较技术,结合三角模糊数来建立模糊判断矩阵.根据水平截集和乐观指标,进行模糊区间的运算,得出熵权,根据熵权大小选出了效能理想的方案.该方法具有一定的工程应用价值,对评价火箭武器系统作战效能提供了分析依据.     

2013—2015年BDS空间信号测距误差的精度评估

基于武汉大学发布的精密星历,计算2013年1月至2015年9月北斗广播星历的轨道、钟差和空间信号测距误差,并对其进行统计分析评估。结果表明：北斗卫星的径向精度总体上优于0.7 m、法向精度总体上优于1.4 m,且无明显的长期变化趋势;在切向精度上,倾斜地球同步轨道和中轨道优于2.1 m,高轨道的切向精度已从14 m左右提升至8 m左右;北斗高轨道、倾斜地球同步轨道、中轨道的钟差精度分别为6.3 ns, 4.7 ns, 4.3 ns;所有卫星的钟差精度总体上优于6 ns;所有卫星的空间信号误差精度总体上优于2 m,从长期来看,中轨道卫星的空间信号误差精度较为稳定;倾斜地球同步轨道和高轨道卫星的空间信号误差精度存在一定的波动。