智能时代的军事训练变革

随着智能技术的发展,人类已逐步迈入智能时代,而智能时代催生了军事训练变革。本文从智能技术影响军事训练典型领域的角度,分析了智能时代背景下,以大数据和人工智能为核心的智能技术,如何影响军事训练的理念、内容、方式及管理,并催生了这些领域的变革。研究表明,智能时代发展背景下,军事训练理念将更加先进,训练内容更加融合,训练方式更加有效,训练管理更加精准。     

Interface defeat studies of long-rod projectile impacting on ceramic targets

The interface defeat phenomenon always occurs when a long-rod projectile impacting on the ceramic target with certain velocity, i.e., the projectile is forced to flow radially on the surface of ceramic plates for a period of time without significant penetration. Interface defeat has a direct effect upon the ballistic performance of the armor piercing projectile, which is studied numerically and theoretically at present. Firstly, by modeling the projectiles and ceramic targets with the SPH (Smoothed Particle Hydrodynamics) particles and Lagrange finite elements, the systematic numerical simulations on interface defeat are performed with the commercial finite element program AUTODYN. Three different responses, i.e., complete interface defeat, dwell and direct penetration, are reproduced in different types of ceramic targets (bare, buffered, radially confined and oblique). Furthermore, by adopting the validated numerical algorithms, constitutive models and the corresponding material parameters, the influences of projectile (material, diameter, nose shape), constitutive models of ceramic (JH-1 and JH-2 models), buffer and cover plate (thickness, constraints, material), as well as the prestress acted on the target (radial and hydrostatic) on the interface defeat (transition velocity and dwell time) are systematically investigated. Finally, based on the energy conservation approach and taking the strain rate effect of ceramic material into account, a modified model for predicting the upper limit of transition velocity is proposed and validated. The present work and derived conclusions can provide helpful reference for the design and optimization of both the long-rod projectile and ceramic armor.     

An investigation on anti-impact and penetration performance of basalt fiber composites with different weave and lay-up modes

The woven basalt fiber composites (WBFC) and the unidirectional [0°/90°/45°/-45°]_s basalt fiber composites (UBFC) were prepared by hot-pressing. Three-point bending test, low velocity impact test, and ballistic test were performed to the prepared composites. After the tests, the specimens were recovered and analyzed for micromorphology. Three-point bending tests show that both the bending strength and stiffness of the WBFC surpass those of the UBFC. Low velocity impact test results show that the low velocity impact resistance to hemispherical impactor of the UBFC is higher than that of the WBFC, but the low velocity impact resistance to sharp impactor of the UBFC is lower than that of the WBFC. For the ballistic test, it can be found that the ballistic property of the UBFC is higher than that of the WBFC. After the tests, microscopic analysis of the specimens was applied, and their failure mechanism was discussed. The main failure modes of the UBFC are delamination and fibers breakage under the above loading conditions while the main failure mode of the WBFC is fibers breakage. Although delamination damage can be found in the WBFC under the above loading conditions, the degree of delamination is far less than that of the UBFC.     

The Gravity of Arms

The aim of this paper is to investigate the determinants of international arms transfers in a gravity model framework. By distinguishing between the decision to export arms (extensive margin) and the value of the arms exported (intensive margin), while also considering its interdependence, is what differentiates this paper from previous research. A theoretically justified gravity model of trade augmented with political and security motives is estimated using a two-stage panel data approach for 104 exporting countries over the period from 1950 to 2007. In addition to the usual gravity variables related to the economic mass of the trading countries and the trade cost factors, the model is extended with political and security factors. The level of democracy in both trading partners, political differences between trading partners and voting similarity with the United States in the UN General Assembly of the countries engaged in trade are the main political factors, whereas the existence of conflicts, military pacts, and embargoes are taken as security motives. The key result indicates that both political and security motives are an important determinant of an arms trade, but their effects on the extensive margin of exports (the decision to order a transfer) differs from their effect on the intensive margin (average value of exports). Moreover, the relative importance of the factors under study has changed since 1989. In the post-cold war period, countries that are less democratic are more likely to export arms, military pacts are less relevant and embargoes play a role.     

Buy now,pay later: American military intervention and the strategic cost paradox

This paper explores the notion that US efforts to evade the political costs of war paradoxically contribute to the subsequent exacerbation of costs over time. Leaders seek to purchase political capital in the short term by limiting the costs and requirements of military operations, but in doing so cause strategic and political liabilities to mount in the long run. While identification of such behaviour is not new, insufficient attention has been devoted to explaining its causes, dynamics, and manifestations in relation to key decisions on and in war. Evidence derived from studies of recent American discretionary campaigns is analysed to advance an argument with respect to this pattern of self-defeating strategic behaviour.     

On the roles of free play in army exercises and the Russians

The article outlines the essential role of free play elements in various types of exercises for the development of in-depth and practical military professionalism. It thereafter argues why such use of free play contradicts the military science founded Russian Way of War.     

Regular and irregular forces in conflict: nineteenth century insurgencies in South America

ABSTRACT

In the decades following independence from Spain, ‘civil wars’ ravaged the newly established polities in South America. Former vice-regal capitals inherited a larger portion of the colonial administration and had larger economic resources and a hegemonic project they were able to have permanent and professional armed forces, capable of leading the offensive and giving battle following the European rules of military art. The central hypothesis of this work is that there is a necessary relationship between the shape of these asymmetrical conflicts, their outcome and the political territorial configuration of each country in post-revolutionary Spanish America. When permanent armies took over from local militias, the capital kept the integrity of its territories and there was a tendency towards political centralization. When this did not happen and the militias managed to find a way to defeat their centralizing enemies, the local powers had an opportunity to renegotiate their participation in the political body, and sought to maintain their independence, which was manifest in federal agreements, otherwise a process of territorial fragmentation began. More than a difference between regular and irregular forces there was one between intermittent, and permanent mobilization.     

阵列雷达自适应多零点单脉冲群目标测角算法

针对阵列体制雷达,由极大似然估计导出自适应多零点单脉冲测角原理。分析发现迭代步长过大导致双零点单脉冲技术在多目标条件下失效,因此提出加权步长改进角度估计的迭代过程,只需要较少计算量就能实现群内多个目标的精确测角。仿真结果表明：该算法在较高信噪比条件下可以精确测量群内三个目标角度,测角误差约为0.15倍波束宽度;当群目标数较多或者目标相位差接近于0时,算法性能下降明显。     

北斗系统新民用导航电文历书参数算法与性能分析

研究新公布的北斗民用导航电文中的两类历书与北斗二号导航电文历书的差异,对比分析各类历书对接收机首次定位时间的影响。利用实际的历书数据,比较不同历书类型的用户算法,分析不同龄期数据对接收机首次定位性能的影响。结果表明,高精度历书在1周的数据龄期内性能较为稳定,中等精度历书精度稍逊于高精度历书,但由于简化了电文空间,能接近高精度历书性能。简约历书进一步简化了参数数目和电文空间,尽管位置误差达到了数百千米,但却能在数月之后保持相应精度,有利于缩短接收机首次定位时间。     

横向效应增强型弹垂直侵彻薄靶的轴向剩余速度理论分析

为了得到横向效应增强型弹（Penetration with Enhanced Lateral Efficiency projectile, PELE）对金属薄靶垂直侵彻后的弹体轴向剩余速度,运用平面冲击波理论,对PELE的侵彻机理进行分析。参照平头弹体对靶板的侵彻模型,将PELE侵彻过程中的能量损失划分为以下几个部分：外壳体和内芯撞靶区域对应的环形塞块获得的能量、冲击波作用下弹体的内能增量以及剪切耗能等。然后根据能量守恒原理,得到PELE垂直侵彻金属薄靶后的PELE弹体轴向剩余速度的理论模型。为了验证该模型的合理性和准确性,设计相应的试验进行验证。结果表明,不同条件下得到的试验结果和理论模型得到的计算结果均吻合得较好。因此,得到的PELE垂直侵彻薄靶的轴向剩余速度理论模型可为工程应用提供指导和参考。