土中爆炸对埋地管线冲击作用的数值模拟分析

为了研究土中爆炸作用下埋地管线的安全问题,利用AUTODYN-2D、AU?TODYN-3D程序,采用程序提供的流固耦合功能和网格映射功能,对爆炸地冲击作用下埋地管线的变形和破坏问题进行了数值模拟分析,得到不同爆心间距管线的应力峰值.将模拟计算结果和理论计算结果进行了对比分析,结果表明:模拟计算值与TM5-855-1手册理论计算值比较吻合,表明采用数值模拟方法分析爆炸地冲击对埋地管线的作用是可行的,计算结果对地下爆破的安全施工和埋地管线的安全运行具有参考价值.     

Analysis on damage characteristics and detonation performance of solid rocket engine charge subjected to jet

To further explore the damage characteristics and impact response of the shaped charge to the solid rocket engine (SRE) in storage or transportation, protective armor was designed and the shelled charges model (SCM)/SRE with protective armor impacting by shaped charge tests were conducted. Air overpressures at 5 locations and axial acceleration caused by the explosion were measured, and the experimental results were compared with two air overpressure curves of propellant detonation obtained by related scholars. Afterwards, the finite element software AUTODYN was used to simulate the SCM impacted process and SRE detonation results. The penetration process and the formation cause of damage were analyzed. The detonation performance of TNT, reference propellant, and the propellant used in this experiment was compared. The axial acceleration caused by the explosion was also analyzed. By comprehensive comparison, the energy released by the detonation of this propellant is larger, and the HMX or Al particles contained in this propellant are more than the reference propellant, with a TNT equivalent of 1.168–1.196. Finally, advanced protection armor suggestions were proposed based on the theory of woven fabric rubber composite armor (WFRCA).     

舰船单元结构模型水下接触爆炸破口试验研究

以 3种舰船单元结构模型水下接触爆炸试验为基础 ,对结构模型所产生的变形、破口尺寸、破口形状进行了观测与分析 ,查找并发现结构中的薄弱环节 .提出了板架结构加强筋相对刚度概念 ,确定了破口长度的估算系数 ,同时为舰船结构在水下爆炸作用下的破口数值计算提供了试验数据 ,如材料断裂极限应变等     

一起灭火器爆炸案的原因调查

全面调查和分析了某住宅公寓灭火器爆炸事故的事故原因及相关责任，得出造成灭火器爆炸的根本原因是灭火器所充装的ABC干粉存在严重质量问题的认定，并依据相关法律将该案件作为刑事案件移交公安部门。     

弹性压杆稳定性的一般表达式

本文推导出等截面弹性压杆稳定性的一般表达式。17种在各种边界条件下的弹性压杆的临界压力计算公式均是它的特殊情况。     

基于封闭爆炸的弹药破片空间分布研究

通过典型弹丸爆炸试验,研究封闭条件下破片的空间分布,提出了爆炸洞体防护的重点区域。试验表明:对于某型高弹丸,主要分布在以弹丸为爆炸中心的20°角的环状严重区域内;对于某型加弹丸,主要分布在以弹丸为爆炸中心的35°角的环状严重区域内。     

焊接切割与火灾

焊割火灾事故呈上升趋势。文章分析了焊割火灾爆炸危险性,并提出了预防措施。     

H2可以作为o-H2和p-H2的混合物处理吗? —兼释H2的残余熵

本文阐述了H_2不能作为正氢和仲氢的混合物处理的理由,提出了从光谱熵的定义出发解释H_2的残余熵的方法。     

Real-time calculation of fragment velocity for cylindrical warheads

To simulate explosion fragments, it is necessary to predict many variables such as fragment velocity, size distribution and projection angle. For active protection systems these predictions need to be made very quickly, before the weapon hits the target. Fast predictions also need to be made in real time simulations when the impact of many different computer models need to be assessed. The research presented in this paper focuses on creating a fast and accurate estimate of one of these variables - the initial fragment velocity. The Gurney equation was the first equation to calculate initial fragment velocity. This equation, sometimes with modifications, is still used today where finite element analysis or complex mathematical approaches are considered too computationally expensive. This paper enhances and improves Breech’s two-dimensional Gurney equation using available empirical data and the principals of conservation of momentum and energy. The results are computationally quick, providing improved accuracy for estimating initial fragment velocity. This will allow the developed model to be available for real-time simulation and fast computation, with improved accuracy when compared to existing approaches.     

水下爆炸中自由场压力和船体壁压的测量与分析

对水下爆炸中自由场压力的水面截断效应及冲击裁荷与船体相互作用的船体壁压进行了分析,得出了自由场压力的水面截断效应及早期的船体壁压计算近似公式.测量结果表明,球形装药中心起爆后形成的冲击波一般不是一条光滑曲线,而是会有多个振荡峰;当自由场压力测点离水面较近时,测量的自由场压力会出现明显的水面截断现象;船板在水中爆炸冲击渡的作用下产生的运动和变形对水中压力场有很大影响,舰体壁压反射系数与冲击波的入射角度有关.