Defence Technology(防务技术)最新文献

An isogeometric analysis approach for dynamic response of doubly-curved magneto electro elastic composite shallow shell subjected to blast loading 承受爆炸荷载的双曲面磁电弹性复合浅壳动态响应的等距分析方法

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.06.005

Pham Hoang Tu , Tran Van Ke , Vu Khac Trai , Le Hoai

For the first time, the isogeometric analysis (IGA) approach is used to model and analyze free and forced vibrations of doubly-curved magneto-electro-elastic (MEE) composite shallow shell resting on the visco-Pasternak foundation in a hygro-temperature environment. The doubly-curved MEE shallow shell types include spherical shallow shell, cylindrical shallow shell, saddle shallow shell, and elliptical shallow shell subjected to blast load are investigated. The Maxwell equation and electromagnetic boundary conditions are used to determine the vary of the electric and magnetic potentials. The MEE shallow shell's equations of motion are derived from Hamilton's principle and refined higher-order shear theory. Then, the IGA method is used to derive the laws of natural frequencies and dynamic responses of the shell under various boundary conditions. The accuracy of the model and method is verified through reliable numerical comparisons. Aside from this, the impact of the input parameters on the free and forced vibration of the doubly-curved MEE shallow shell is examined in detail. These results may be useful in the design and manufacture of military structures such as warships, fighter aircraft, drones and missiles.

首次使用等几何分析（IGA）方法对在粘滞-帕斯捷尔纳克地基上的双曲面磁弹性（MEE）复合浅壳在湿温环境下的自由振动和受迫振动进行建模和分析。研究了承受爆炸荷载的双曲面 MEE 浅壳类型，包括球形浅壳、圆柱形浅壳、马鞍形浅壳和椭圆形浅壳。采用麦克斯韦方程和电磁边界条件来确定电势和磁势的变化。MEE 浅壳的运动方程由汉密尔顿原理和精炼的高阶剪切理论推导得出。然后，使用 IGA 方法推导出各种边界条件下壳的固有频率和动态响应规律。通过可靠的数值比较，验证了模型和方法的准确性。此外，还详细研究了输入参数对双曲面 MEE 浅壳自由振动和受迫振动的影响。这些结果可能有助于军舰、战斗机、无人机和导弹等军事结构的设计和制造。

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引用次数: 0

Developing a highly scalable synthetic strategy for 5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,b-dioxide (CL-18) and investigating the influence of crystal engineering and positional isomerization on its safety and laser ignition performance 开发 5-氨基-4-硝基苯并[1,2-c:3,4-c']双([1,2,5]恶二唑)1,b-二氧化物 (CL-18) 的高度可扩展合成策略，并研究晶体工程和位置异构化对其安全性和激光点火性能的影响

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.06.008

Lei Yang, Zhenqi Zhang, Wei Du, Jinshan Li, Qing Ma

5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,6-dioxide (CL-18) exhibits significant potential as an initiating explosive. However, its current synthesis process remains non-scalable due to low yields and safety risks. In this study, we have developed a simple and safe synthetic route for CL-18. It was synthesized from 3,5-dihaloanisole in a four-step reaction with an overall yield exceeding 60%, surpassing all reported yields in the literature. Subsequently, recrystallization of CL-18 was successfully achieved by carefully selecting appropriate solvents and antisolvents to reduce its mechanical sensitivity. Ultimately, when DMF-ethanol was employed as the recrystallization solvent system, satisfactory product yield (>90%) and reduced mechanical sensitivity (IS = 15 J; FS = 216 N) were obtained. Additionally, CL-18 is derived from the rearrangement of oxygen atoms on i-CL-18 furoxan, and a comparative analysis of their physicochemical properties was conducted. The thermal stability of both compounds is similar, with onset decomposition temperatures recorded at 186 and 182 °C respectively. Similarly, they exhibit 5 s breaking point temperatures of 236 and 237 °C. Additionally, we present novel insights into the positional-isomerization-laser-ignition performance of CL-18 and its isomer i-CL-18 using laser irradiation for the first time. Remarkably, our findings demonstrate that i-CL-18 exhibits enhanced laser sensitivity, as it can be directly ignited by a 1064 nm wavelength laser, whereas CL-18 lacks this characteristic.

5-氨基-4-硝基苯并[1,2-c:3,4-c']双([1,2,5]恶二唑)1,6-二氧化物（CL-18）作为起爆剂具有巨大的潜力。然而，由于产量低和存在安全风险，其目前的合成工艺仍然不可扩展。在本研究中，我们开发了一种简单安全的 CL-18 合成路线。我们以 3,5-二卤苯甲醚为原料，通过四步反应合成了 CL-18，总收率超过 60%，超过了所有文献报道的收率。随后，通过精心选择适当的溶剂和抗溶剂以降低其机械敏感性，成功实现了 CL-18 的重结晶。最终，当采用 DMF-乙醇作为重结晶溶剂体系时，获得了令人满意的产品收率（大于 90%）和较低的机械敏感性（IS = 15 J；FS = 216 N）。此外，CL-18 是由 i-CL-18 furoxan 上的氧原子重排得到的，并对它们的理化性质进行了比较分析。这两种化合物的热稳定性相似，起始分解温度分别为 186 ℃ 和 182 ℃。同样，它们的 5 秒断裂点温度分别为 236 和 237 ℃。此外，我们还首次利用激光辐照对 CL-18 及其异构体 i-CL-18 的位置异构化-激光点火性能提出了新的见解。值得注意的是，我们的研究结果表明 i-CL-18 具有更高的激光灵敏度，因为它可以被波长为 1064 nm 的激光直接点燃，而 CL-18 则缺乏这一特性。

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引用次数: 0

Ti/WO3, a nanothermite for special purposes: An experimental study Ti/WO3，一种特殊用途的纳米热敏电阻：实验研究

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.06.010

Mateusz Polis , Agnieszka Stolarczyk , Konrad Szydlo , Tomasz Jarosz , Marcin Procek , Sebastian Slawski , Lukasz Hawelek

A new nanothermite system, composed of titanium and tungsten trioxide is reported. Initial investigations show that it has low-average sensitivity to mechanical stimuli (friction, impact), but that its sensitivity to laser irradiation can be controlled in a moderately wide range. The combustion of this nanothermite system takes place at a very high apparent temperature (> 3695 K) and it follows the key predictions of the established reactive sintering mechanism, as supported by SEM-EDS and XRD analyses.

本报告介绍了一种由钛和三氧化钨组成的新型纳米温石棉系统。初步研究表明，它对机械刺激（摩擦、撞击）的平均灵敏度较低，但对激光照射的灵敏度可控制在中等范围内。这种纳米热敏体系的燃烧发生在很高的表观温度下（> 3695 K），它遵循了已确立的反应烧结机制的主要预测，并得到了 SEM-EDS 和 XRD 分析的支持。

引用次数: 0

Modelling of internal ballistics of gun systems: A review 火炮系统内部弹道建模：综述

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.05.004

F. Ongaro, C. Robbe, A. Papy, B. Stirbu, A. Chabotier

A deep understanding of the internal ballistic process and the factors affecting it is of primary importance to efficiently design a gun system and ensure its safe management. One of the main goals of internal ballistics is to estimate the gas pressure into the combustion chamber and the projectile muzzle velocity in order to use the propellant to its higher efficiency while avoiding over-pressure phenomena. Dealing with the internal ballistic problem is a complex undertaking since it requires handling the interaction between different constituents during a transient time lapse with very steep rise of pressure and temperature. Several approaches have been proposed in the literature, based on different assumptions and techniques. Generally, depending on the used mathematical framework, they can be classified into two categories: computational fluid dynamics-based models and lumped-parameter ones. By focusing on gun systems, this paper offers a review of the main contributions in the field by mentioning their advantages and drawbacks. An insight into the limitations of the currently available modelling strategies is provided, as well as some considerations on the choice of one model over another. Lumped-parameter models, for example, are a good candidate for performing parametric analysis and optimisation processes of gun systems, given their minimum requirements of computer resources. Conversely, CFD-based models have a better capacity to address more sophisticated phenomena like pressure waves and turbulent flow effects. The performed review also reveals that too little attention has been given to small calibre guns since the majority of currently available models are conceived for medium and large calibre gun systems. Similarly, aspects like wear phenomena, bore deformations or projectile-barrel interactions still need to be adequately addressed and our suggestion is to dedicate more effort on it.

深入了解内弹道过程及其影响因素对于有效设计火炮系统和确保其安全管理至关重要。内弹道学的主要目标之一是估算进入燃烧室的气体压力和弹丸的炮口速度，以便更有效地使用推进剂，同时避免过压现象。处理内弹道问题是一项复杂的工作，因为它需要在压力和温度急剧上升的瞬时过程中处理不同成分之间的相互作用。文献中提出了几种基于不同假设和技术的方法。一般来说，根据所使用的数学框架，这些方法可分为两类：基于计算流体动力学的模型和整块参数模型。本文以喷枪系统为重点，对该领域的主要贡献进行了回顾，提到了它们的优点和缺点。本文深入探讨了当前可用建模策略的局限性，以及在选择一种模型时的一些考虑因素。例如，考虑到对计算机资源的最低要求，整数参数模型是对火炮系统进行参数分析和优化过程的理想选择。相反，基于 CFD 的模型则更有能力处理更复杂的现象，如压力波和湍流效应。所进行的审查还显示，对小口径火炮的关注太少，因为目前可用的大多数模型都是为中口径和大口径火炮系统设计的。同样，磨损现象、枪膛变形或弹丸与枪管之间的相互作用等方面的问题仍有待充分解决，我们建议在这方面投入更多精力。

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引用次数: 0

A review of extreme condition effects on solder joint reliability: Understanding failure mechanisms 回顾极端条件对焊点可靠性的影响：了解失效机制

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.05.013

Norliza Ismail , Wan Yusmawati Wan Yusoff , Azuraida Amat , Nor Azlian Abdul Manaf , Nurazlin Ahmad

Solder joint, crucial component in electronic systems, face significant challenges when exposed to extreme conditions during applications. The solder joint reliability involving microstructure and mechanical properties will be affected by extreme conditions. Understanding the behaviour of solder joints under extreme conditions is vital to determine the durability and reliability of solder joint. This review paper aims to comprehensively explore the underlying failure mechanism affecting solder joint reliability under extreme conditions. This study covers an in-depth analysis of effect extreme temperature, mechanical stress, and radiation conditions towards solder joint. Impact of each condition to the microstructure including solder matrix and intermetallic compound layer, and mechanical properties such as fatigue, shear strength, creep, and hardness was thoroughly discussed. The failure mechanisms were illustrated in graphical diagrams to ensure clarity and understanding. Furthermore, the paper highlighted mitigation strategies that enhancing solder joint reliability under challenging operating conditions. The findings offer valuable guidance for researchers, engineers, and practitioners involved in electronics, engineering, and related fields, fostering advancements in solder joint reliability and performance.

焊点是电子系统中的关键部件，在应用过程中暴露于极端条件下会面临重大挑战。焊点的可靠性涉及微观结构和机械性能，会受到极端条件的影响。了解焊点在极端条件下的行为对于确定焊点的耐用性和可靠性至关重要。本文旨在全面探讨极端条件下影响焊点可靠性的潜在失效机制。本研究深入分析了极端温度、机械应力和辐射条件对焊点的影响。深入讨论了各种条件对微观结构（包括焊料基体和金属间化合物层）以及机械性能（如疲劳、剪切强度、蠕变和硬度）的影响。为确保清晰和易懂，还通过图表对失效机制进行了说明。此外，论文还强调了在具有挑战性的操作条件下提高焊点可靠性的缓解策略。研究结果为电子、工程和相关领域的研究人员、工程师和从业人员提供了宝贵的指导，促进了焊点可靠性和性能的提高。

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引用次数: 0

An equivalent target plate damage probability calculation mathematics model and damage evaluation method 等效靶板损伤概率计算数学模型和损伤评估方法

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.06.006

Hanshan Li, Xiaoqian Zhang

Aiming at the requirement of damage testing and evaluation of equivalent target plate based on the explosion of intelligent ammunition, this paper proposes a novel method for damage testing and evaluation method of circumferential equivalent target plate. Leveraging the dispersion characteristics parameters of fragment, we establish a calculation model of the fragment power situation and the damage calculation model under the condition of fragment ultimate penetration equivalent target plate. The damage model of equivalent target plate involves the fragment dispersion density, the local perforation damage criterion, the tearing damage model, and the damage probability. We use the camera to obtain the image of the equivalent target plate with fragment perforation, and research the algorithm of fragment distribution position recognition and fragment perforation area calculation method on the equivalent target plate by image processing technology. Based on the obtained parameters of the breakdown position and perforation area of fragments on equivalent target plate, we apply to damage calculation model of equivalent target plate, and calculate the damage probability of each equivalent target plate, and use the combined probabilistic damage calculation method to obtain the damage evaluation results of the circumferential equivalent target plate in an intelligent ammunition explosion experiment. Through an experimental testing, we verify the feasibility and rationality of the proposed damage evaluation method by comparison, the calculation results can reflect the actual damage effect of the equivalent target plate.

针对基于智能弹药爆炸的等效靶板损伤测试与评估要求，本文提出了一种新颖的圆周等效靶板损伤测试与评估方法。利用破片的弥散特性参数，建立破片威力情况计算模型和破片极限穿透等效靶板条件下的损伤计算模型。等效靶板损伤模型包括碎片弥散密度、局部穿孔损伤判据、撕裂损伤模型和损伤概率。我们利用相机获取了带破片穿孔的等效靶板图像，并利用图像处理技术研究了等效靶板破片分布位置识别算法和破片穿孔面积计算方法。根据得到的等效靶板上碎片击穿位置和击穿面积参数，应用等效靶板损伤计算模型，计算各等效靶板的损伤概率，并采用概率损伤组合计算方法，得到智能弹药爆炸实验中圆周等效靶板的损伤评估结果。通过实验测试，对比验证了所提损伤评价方法的可行性和合理性，计算结果能够反映等效靶板的实际损伤效果。

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引用次数: 0

Ballistic limit velocity of small caliber projectiles against SS400 steel plates: Live fire experiments and empirical models 小口径射弹对 SS400 钢板的弹道极限速度：实弹实验和经验模型

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.07.008

Jong-Hwan Kim , Seungwon Baik , Jirui Fu , Joon-Hyuk Park

This study presents the ballistic limit velocity of small caliber projectiles against SS400 steel plate derived from live-fire ballistic experiments. Four different small caliber projectiles were tested against SS400 steel plates of 9 mm, 10 mm, and 12 mm thicknesses. The ballistic limit velocity was calculated using two standard methods, MIL-STD-662F and NIJ-STD-0101.06, and additionally using a support vector machine algorithm. The results show a linear relationship between the plate thickness and ballistic limit velocity. Further, the relative penetration performance among five different small caliber projectiles was analyzed using the Penetration Performance Ratio (PPR) introduced in this study, which suggests the potential of PPR to predict the ballistic limit velocity of other untested materials and/or different projectiles.

本研究介绍了实弹弹道实验得出的小口径射弹对 SS400 钢板的弹道极限速度。针对厚度分别为 9 毫米、10 毫米和 12 毫米的 SS400 钢板，测试了四种不同的小口径射弹。弹道极限速度是采用 MIL-STD-662F 和 NIJ-STD-0101.06 两种标准方法以及支持向量机算法计算得出的。结果表明，钢板厚度与弹道极限速度之间存在线性关系。此外，还使用本研究中引入的穿透性能比（PPR）分析了五种不同小口径射弹的相对穿透性能，这表明 PPR 有潜力预测其他未测试材料和/或不同射弹的弹道极限速度。

引用次数: 0

Physics-informed machine learning model for prediction of ground reflected wave peak overpressure 预测地面反射波峰值超压的物理信息机器学习模型

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.06.004

Haoyu Zhang , Yuxin Xu , Lihan Xiao , Canjie Zhen

The accurate prediction of peak overpressure of explosion shockwaves is significant in fields such as explosion hazard assessment and structural protection, where explosion shockwaves serve as typical destructive elements. Aiming at the problem of insufficient accuracy of the existing physical models for predicting the peak overpressure of ground reflected waves, two physics-informed machine learning models are constructed. The results demonstrate that the machine learning models, which incorporate physical information by predicting the deviation between the physical model and actual values and adding a physical loss term in the loss function, can accurately predict both the training and out-of-training dataset. Compared to existing physical models, the average relative error in the predicted training domain is reduced from 17.459%–48.588% to 2%, and the proportion of average relative error less than 20% increased from 0% to 59.4% to more than 99%. In addition, the relative average error outside the prediction training set range is reduced from 14.496%–29.389% to 5%, and the proportion of relative average error less than 20% increased from 0% to 71.39% to more than 99%. The inclusion of a physical loss term enforcing monotonicity in the loss function effectively improves the extrapolation performance of machine learning. The findings of this study provide valuable reference for explosion hazard assessment and anti-explosion structural design in various fields.

在爆炸危险评估和结构保护等领域，爆炸冲击波是典型的破坏元素，因此准确预测爆炸冲击波的峰值超压意义重大。针对现有物理模型预测地面反射波峰值超压精度不足的问题，构建了两个物理信息机器学习模型。结果表明，机器学习模型通过预测物理模型与实际值之间的偏差并在损失函数中加入物理损失项，结合了物理信息，可以准确预测训练数据集和训练外数据集。与现有的物理模型相比，预测训练域的平均相对误差从 17.459%-48.588% 降低到 2%，平均相对误差小于 20% 的比例从 0% 至 59.4% 增加到 99% 以上。此外，预测训练集范围外的相对平均误差从 14.496%-29.389% 降至 5%，相对平均误差小于 20% 的比例从 0% 至 71.39% 增加到 99% 以上。在损失函数中加入强制单调性的物理损失项，有效提高了机器学习的外推性能。该研究结果为各领域的爆炸危险评估和防爆结构设计提供了宝贵的参考。

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引用次数: 0

Analysis model for damage of reinforced bars in RC beams under contact explosion 接触爆炸下钢筋混凝土梁中钢筋损坏的分析模型

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.03.003

Chaozhi Yang , Zhengxiang Huang , Xin Jia , Wei Shang , Jian Zhang

The load-bearing capacity of reinforced concrete (RC) beams primarily relies on internal reinforced bars. However, limited research has been conducted on the dynamic response of these bars. To address this gap, this study has established an analytical model using dimensional analysis for calculating the deformation of reinforced bars within RC beams subjected to contact explosion. Comparison with experimental data reveals that the model has a relative error of 5.22%, effectively reflecting the deformation of reinforced bars. Additionally, based on this model, the study found that while concrete does influence the deformation of reinforced bars, this influence can be disregarded in comparison to the material properties of the bars themselves. The findings of this study have implications for calculating the residual load-bearing capacity of damaged RC beams, evaluating the extent of damage to RC beams after blast loading, and providing guidance for the blast-resistant design of RC structures.

钢筋混凝土（RC）梁的承载能力主要依靠内部钢筋。然而，有关这些钢筋动态响应的研究却十分有限。针对这一空白，本研究利用尺寸分析建立了一个分析模型，用于计算钢筋混凝土梁内部钢筋在接触爆炸情况下的变形。与实验数据对比发现，该模型的相对误差为 5.22%，能有效反映钢筋的变形情况。此外，根据该模型，研究发现虽然混凝土确实会影响钢筋的变形，但与钢筋本身的材料特性相比，这种影响可以忽略不计。本研究的结果对计算受损钢筋混凝土梁的剩余承载力、评估钢筋混凝土梁在爆炸荷载后的受损程度以及指导钢筋混凝土结构的抗爆设计具有重要意义。

引用次数: 0

Composite armor philosophy (CAP): Holistic design methodology of multi-layered composite protection systems for armored vehicles 复合装甲理念（CAP）：装甲车辆多层复合防护系统的整体设计方法

IF 5 Q1 ENGINEERING, MULTIDISCIPLINARY

Defence Technology(防务技术)

Pub Date : 2024-11-01 DOI: 10.1016/j.dt.2024.07.009

Evangelos Ch. Tsirogiannis , Foivos Psarommatis , Alexandros Prospathopoulos , Georgios Savaidis

A philosophy for the design of novel, lightweight, multi-layered armor, referred to as Composite Armor Philosophy (CAP), which can adapt to the passive protection of light-, medium-, and heavy-armored vehicles, is presented in this study. CAP can serve as a guiding principle to assist designers in comprehending the distinct roles fulfilled by each component. The CAP proposal comprises four functional layers, organized in a suggested hierarchy of materials. Particularly notable is the inclusion of a ceramic-composite principle, representing an advanced and innovative solution in the field of armor design. This paper showcases real-world defense industry applications, offering case studies that demonstrate the effectiveness of this advanced approach. CAP represents a significant milestone in the history of passive protection, marking an evolutionary leap in the field. This philosophical approach provides designers with a powerful toolset with which to enhance the protection capabilities of military vehicles, making them more resilient and better equipped to meet the challenges of modern warfare.

本研究提出了一种新型、轻质、多层装甲的设计理念，即复合装甲理念（CAP），它能适应轻型、中型和重型装甲车辆的被动防护。CAP 可作为一项指导原则，帮助设计人员理解每个组件所发挥的不同作用。CAP 方案包括四个功能层，按照建议的材料层次进行组织。尤其值得注意的是，其中包含了陶瓷复合材料原理，这代表了装甲设计领域的先进和创新解决方案。本文展示了国防工业的实际应用，通过案例研究证明了这种先进方法的有效性。CAP 是被动防护史上的一个重要里程碑，标志着该领域的一次飞跃。这种哲学方法为设计人员提供了一个强大的工具集，可用于增强军用车辆的防护能力，使其更有弹性，更好地应对现代战争的挑战。

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引用次数: 0