Defence Technology最新文献

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Research status and challenges in the manufacturing of IR conformal optics 红外保偏光学器件制造的研究现状与挑战

IF 5.1 2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2024-04-27 DOI: 10.1016/j.dt.2024.04.015

Jianbo Zhao, Sheng Wang, Chunyu Zhang, Jinhu Wang, Qingliang Zhao

The infrared conformal window is one of the most critical components in aircraft. Conformal windows with high performance bring low aberrations, high aerodynamic performance, reliability in extreme working environments, and added value for aircraft. Through the past decades, remarkable advances have been achieved in manufacturing technologies for conformal windows, where the machining accuracy approaches the nanometer level, and the surface form becomes more complex. These advances are critical to aircraft development, and these manufacturing technologies also have significant reference values for other directions of the ultra-precision machining field. In this review, the infrared materials suitable for manufacturing conformal windows are introduced and compared with insights into their performances. The remarkable advances and concrete work accomplished by researchers are reviewed. The challenges in manufacturing conformal windows that should be faced in the future are discussed.

红外保形窗是飞机上最关键的部件之一。高性能的保形窗具有低像差、高气动性能、在极端工作环境下的可靠性，并能为飞机带来附加值。过去几十年来，保形窗制造技术取得了显著进步，加工精度接近纳米级，表面形状也变得更加复杂。这些进步对飞机的发展至关重要，同时这些制造技术也对超精密加工领域的其他方向具有重要的参考价值。本综述介绍了适用于制造保形窗的红外材料，并比较了这些材料的性能。此外，还回顾了研究人员取得的重大进展和完成的具体工作。还讨论了未来在制造保形窗方面应面临的挑战。

引用次数: 0

Data-driven prediction of dimensionless quantities for semi-infinite target penetration by integrating machine-learning and feature selection methods 通过整合机器学习和特征选择方法，以数据驱动预测半无限目标穿透的无量纲数量

IF 5.1 2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2024-04-27 DOI: 10.1016/j.dt.2024.04.012

Qingqing Chen, Xinyu Zhang, Zhiyong Wang, Jie Zhang, Zhihua Wang

This study employs a data-driven methodology that embeds the principle of dimensional invariance into an artificial neural network to automatically identify dominant dimensionless quantities in the penetration of rod projectiles into semi-infinite metal targets from experimental measurements. The derived mathematical expressions of dimensionless quantities are simplified by the examination of the exponent matrix and coupling relationships between feature variables. As a physics-based dimension reduction methodology, this way reduces high-dimensional parameter spaces to descriptions involving only a few physically interpretable dimensionless quantities in penetrating cases. Then the relative importance of various dimensionless feature variables on the penetration efficiencies for four impacting conditions is evaluated through feature selection engineering. The results indicate that the selected critical dimensionless feature variables by this synergistic method, without referring to the complex theoretical equations and aiding in the detailed knowledge of penetration mechanics, are in accordance with those reported in the reference. Lastly, the determined dimensionless quantities can be efficiently applied to conduct semi-empirical analysis for the specific penetrating case, and the reliability of regression functions is validated.

本研究采用数据驱动方法，将尺寸不变性原理嵌入人工神经网络，从实验测量结果中自动识别棒状射弹穿透半无限金属目标时的主要无量纲量。通过检查指数矩阵和特征变量之间的耦合关系，简化了无量纲量的数学表达式。作为一种基于物理学的维度缩减方法，这种方法将高维参数空间缩减为在穿透情况下只涉及几个物理上可解释的无量纲量的描述。然后，通过特征选择工程评估了四种撞击条件下各种无量纲特征变量对穿透效率的相对重要性。结果表明，通过这种协同方法，无需参考复杂的理论方程，也无需借助详细的穿透力学知识，所选择的关键无量纲特征变量与参考文献中的变量一致。最后，确定的无量纲量可以有效地应用于对特定穿透情况进行半经验分析，并验证了回归函数的可靠性。

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引用次数: 0

Perspectives on additive manufacturing for warhead applications 增材制造在弹头应用中的前景

IF 5.1 2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2024-03-19 DOI: 10.1016/j.dt.2024.02.010

Hao Xue, Qiang Zhou, Chuan Xiao, Guangyan Huang

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引用次数: 0

Blast injury risks to humans within a military trench 军事战壕内的爆炸对人体造成伤害的风险

IF 5.1 2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2024-03-01 DOI: 10.1016/j.dt.2024.03.006

I. Edri

引用次数: 0

Non-dimensional analysis on blast wave propagation in foam concrete: Minimum thickness to avoid stress enhancement 泡沫混凝土中爆炸波传播的非尺寸分析：避免应力增强的最小厚度

IF 5.1 2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2023-12-22 DOI: 10.1016/j.dt.2023.12.005

Ya Yang, Xiangzhen Kong, Qin Fang

Foam concrete is a prospective material in defense engineering to protect structures due to its high energy absorption capability resulted from the long plateau stage. However, stress enhancement rather than stress mitigation may happen when foam concrete is used as sacrificial claddings placed in the path of an incoming blast load. To investigate this interesting phenomenon, a one-dimensional difference model for blast wave propagation in foam concrete is firstly proposed and numerically solved by improving the second-order Godunov method. The difference model and numerical algorithm are validated against experimental results including both the stress mitigation and the stress enhancement. The difference model is then used to numerically analyze the blast wave propagation and deformation of material in which the effects of blast loads, stress–strain relation and length of foam concrete are considered. In particular, the concept of minimum thickness of foam concrete to avoid stress enhancement is proposed. Finally, non-dimensional analysis on the minimum thickness is conducted and an empirical formula is proposed by curve-fitting the numerical data, which can provide a reference for the application of foam concrete in defense engineering.

泡沫混凝土具有较长的高原阶段，因此具有较高的能量吸收能力，是国防工程中保护结构的一种有前途的材料。然而，如果将泡沫混凝土用作牺牲性覆盖物，并将其放置在爆炸荷载进入的路径上，则可能会出现应力增强而非应力减缓的情况。为了研究这一有趣的现象，首先提出了泡沫混凝土中爆炸波传播的一维差分模型，并通过改进二阶戈杜诺夫方法进行数值求解。差分模型和数值算法与包括应力减缓和应力增强在内的实验结果进行了验证。然后，利用差分模型对爆炸波传播和材料变形进行数值分析，其中考虑了爆炸荷载、应力应变关系和泡沫混凝土长度的影响。特别是提出了泡沫混凝土最小厚度的概念，以避免应力增强。最后，对最小厚度进行了非尺寸分析，并通过对数值数据进行曲线拟合，提出了经验公式，为泡沫混凝土在国防工程中的应用提供了参考。

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引用次数: 0

On Uniform Consistency of Neyman’s Type Nonparametric Tests Neyman型非参数检验的一致相合性

IF 0.2 2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2023-06-01 DOI: 10.1134/S106345412302005X

M. Ermakov, D. Kapatsa

引用次数: 0

A review on lightweight materials for defence applications: A present and future developments 轻质国防材料的研究进展

2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2023-03-01 DOI: 10.1016/j.dt.2023.02.025

S. Siengchin

引用次数: 21

A simulation method on target strength and circular SAS imaging of X-rudder UUV including multiple acoustic scattering 考虑多重声散射的x舵UUV目标强度和圆形SAS成像仿真方法

2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2023-02-01 DOI: 10.1016/j.dt.2023.02.008

Wenhuan Wang, Bin Wang, Jun Fan, Fulin Zhou, K. Zhao, Zhou Jiang

引用次数: 0

Nacre-inspired interface structure design of polymer bonded explosives toward significantly enhanced mechanical performance 基于核珠的聚合物粘结炸药界面结构设计可显著提高其力学性能

2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2022-11-01 DOI: 10.1016/j.dt.2022.10.013

W. Peng, Chen You-long, L. Meng, Sun Yin-shuang, Yu Dai, Xin Li, Jie Chen, Yang Zhi-jian, Guan-song He

引用次数: 0

IQR-based approach for DDoS detection and mitigation in SDN 基于iqr的SDN DDoS检测与缓解方法

2区工程技术 Q1 Engineering

Defence Technology

Pub Date : 2022-10-01 DOI: 10.1016/j.dt.2022.10.006

Rochak Swami, M. Dave, Virender Ranga

引用次数: 1

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