Analysis of the mass of behind-armor debris generated by RHA subjected to normal penetration of variable cross-section EFP

Analyzing the mass of behind-armor debris (BAD) generated by Rolled Homogeneous Armor (RHA) subjected to normal penetration of variable cross-section Explosively Formed Projectile (EFP) is the purpose of this paper. So theoretical analysis, numerical simulation and experimental data are combined to analyze the influence of variable cross-section characteristic on the time history of crater radius. Moreover the relationships between time history of crater radius (as well as mass of BAD) and the thickness of RHA (from 30mm to 70 mm) and the impact velocity of EFP (1650 m/s to 1860 m/s) are also investigated. The results indicate that: 1) being compared to the variable cross-section characteristic is ignored, the theoretical time history of crater radius is in better agreement with the simulation results when the variable cross-section characteristic is considered;2) being compared to the other three conditions of plug, the theoretical mass of BAD is in the best agreement with the simulation results when the shape of plug is frustum of a cone and the angle between generatrix and bottom is 45- and the axial length of mushroom is considered.

异型变径高压喷气管的数值模拟

异型变径管近年来得到广泛应用,但管道复杂的应力分布也为设计和施工带来诸多难题。实际使用中常出现管道开裂现象,造成停水停电等诸多不利影响,所以设计和施工前有必要进行计算机仿真分析。利用FLUET有限元分析软件对异型变径管进行模拟,研究了在常流和非定常流情况下管道内部流体速度和压强的分布情况。模拟结果表明,定常流变径管中部流体速度最大,压强最小;非定常流在入口变径过渡段1/3处,压强最大;在入口段,压强是先小后大再小,出口处是先大后小再大。

异形及圆柱形立井可变调节井圈的设计及应用

在施工异形及圆柱形立井过程中,对立井的浇筑支护所用模板井圈进行了设计,通过设计的新型井圈,解决了异形及圆柱形立井浇筑成型问题,同时也降低了立井井圈的成本,并且可循环使用,提高了经济效益。该井圈的质量、大小都优于传统槽钢井圈,减少了工人的劳动强度,降低了运输抬运大型井圈的安全风险。

青岛邮轮母港联检大厅钢结构设计

青岛邮轮母港联检大厅采用大跨度钢结构屋面,水平投影呈矩形,长轴长度为324m,短轴长度为92.5m。介绍了联检大厅钢结构设计情况,并重点说明了异性截面模拟和计算长度确定等主要技术难点和解决方案。结果表明:采用分段输入的方式来模拟异形变截面是一种精度较高的方法;对于相同刚架单元组成的结构采用屈曲分析确定计算长度是一种简单有效的方法;节点加劲板对于改善节点的应力集中具有明显的效果。