有限宽板应力强度因子的一种近似解法

本文对文献[1]中提出的近似方法,在运用于不同问题之后.发现了该方法的局限性,并提出了改进的措施,取得了明显的效果.     

正交异性矩形板结构弯曲问题的解析解法

板结构为由若干板组成的结构。用解析法求解正交异性板结构的弯曲问题,必须建立一个正交异性矩形板弯曲的横向位移函数为变量的偏微分方程的一般解。这种解能求解任意边界和任意载荷的弯曲问题。对于结构中的每块板,有些边为单独的,可由边界条件来计算,而有些边与其它板边相连接,由连续性条件来计算。由这些条件组成的方程式可以求解一般解中的全部积分常数。以顶边简支底边固定承受静水压力的板结构水池为例,进行了分析计算。     

Experiment and simulation of launching process of a small-diameter steel cartridge case

In order to explore the rules of the deformation force during the launching of a small-diameter steel cartridge, the semi-closed bomb test method is used to test the greatest strains on chamber outer wall under the different chamber pressures. The pressure curves of cartridge chamber are measured in experiment, and the tensile test data of cartridge are loaded into the numerical calculation to compare with the experimental data. The conclusion was obtained that the calculated results match better with the experimental results by considering strain rate bilinear kinematic hardening material constitutive model. The forces on the various parts of the cartridge during launching and their deformation rules are achieved, in which the equivalent plastic strain decreases and the cylinder ring withstands the maximum equivalent stress when the cartridge case clings to the bore from the mouth to the bottom.     

Damage of multi-layer spaced metallic target plates impacted by radial layered PELE

Three different kinds of PELE (the penetrator with lateral efficiency) were launched by ballistic artillery to impact the multi-layer spaced metal target plates. The impact velocities of the projectiles were measured by the velocity measuring system. The damage degree and process of each layer of target plate impacted by the three kinds of projectiles were analyzed. The experimental results show that all the three kinds of projectiles have the effect of expanding holes on the multi-layer spaced metal target plates. For the normal structure PELE(without layered) with tungsten alloy jacket and the radial layered PELE with tungsten alloy jacket, the diameters of holes on the second layer of plates are 3.36 times and 3.76 times of the diameter of the projectile, respectively. For radial layered PELE with W/Zr-based amorphous composite jacket, due to the large number of tungsten wires dispersed after the impact, the diameter of the holes on the four-layer spaced plates can reach 2.4 times, 3.04 times, 5.36 times and 2.68 times of the diameter of the projectile. Besides, the normal structure PELE with tungsten alloy jacket and the radial layered PELE whit tungsten alloy jacket formed a large number of fragments impact marks on the third target plate. Although the number of fragments penetrating the third target plate is not as large as that of the normal structure PELE, the area of dispersion of fragments impact craters on the third target plate is larger by the radial layered PELE. The radial layered PELE with W/Zr-based amorphous composite jacket released a lot of heat energy due to the impact of the matrix material, and formed a large area of ablation marks on the last three target plates.     

金属复合板的消防安全性能探讨

随着我国科技进步及建筑节能需要,特别是近年钢结构建筑体系的推广,金属复合板得到迅猛发展。从分析金属复合板的材料性能和火灾特点入手,就工程施工、使用过程中存在的消防安全问题及防范措施进行了探析。     

厚/薄梁和板的通用动力有限单元

本文以位移模式,从研究通用于厚/薄梁的动力有限单元入手,得到了通于薄板和中厚板的九个自由度三角形和十二个自由度矩形动力有限单元。     

Body armour – New materials,new systems

This is a very timely review of body armour materials and systems since new test standards are currently being written, or reviewed, and new, innovative products released. Of greatest importance, however, is the recent evolution, and maturity, of the Ultra High Molecular Weight Polyethylene fibres enabling a completely new style of system to evolve – a stackable system of Hard Armour Plates. The science of body armour materials is quickly reviewed with emphasis upon current understanding of relevant energy-absorbing mechanisms in fibres, fabrics, polymeric laminates and ceramics. The trend in on-going developments in ballistic fibres is then reviewed, analysed and future projections offered. Weaknesses in some of the ceramic grades are highlighted as is the value of using cladding materials to improve the robustness, and multi-strike performance, of Hard Armour Plates. Finally, with the drive for lighter, and therefore smaller, soft armour systems for military personnel the challenges for armour designers are reported, and the importance of the relative size of the Hard Armour Plate to the Soft Armour Insert is strongly emphasised.     

弹性薄板的条形传递函数单元模型

应用改进的条形传递函数方法 ,建立了弹性薄板的二结线四自由度条形单元模型 ,用于分析系统的静力响应。用结线将矩形区域划分为条形单元 ,将边界结线离散 ,以内部结线和边界结点的位移和转角为未知量 ,采用三次插值 ,得到能够与有限元单元耦合求解的超级单元。利用广义函数给出了一种精确积分方法 ,可以得到有关矩阵的显式表达 ,得到提高了求解精度和效率。     

横向运动板对长杆弹变形及运动影响的数值研究

利用Ls—DYNA软件对钨合金长杆弹垂直侵彻单层和双层横向运动钢板进行了数值计算。通过分析长杆弹的塑性变形、速度降、动能降和横向速度,得到了单层和双层板横向运动速度与影响长杆弹侵彻能力因素的关系。仿真结果表明：随着运动板速度的增加,运动板对长杆弹的侵蚀加剧,长杆弹的速度降、动能降增大;运动板相同速度下,虽然单层板的冲击能使长杆弹获得较大横向速度,但双层板比单层板对长杆弹的干扰效果更明显。     

粘-弹层合板的阻尼振动和横向应力

应用混合分层理论在板的厚度方向取二次插值函数描述每个数值层内位移沿厚度方向的变化规律,采用三次和四次插值函数描述横向应力沿厚度方向的变化,推导出粘-弹层合板的动力学方程,并得出简支粘-弹层合板自由阻尼振动的解.数值结果不仅与三维结果吻合较好,且能够计算合理协调的横向应力.