Defence Technology(防务技术)最新文献_第6页

Taming of trinitromethyl-oxadiazole to access high density and high oxygen balance via a dual modulation strategy 通过双重调制策略驯服三硝基甲基恶二唑，实现高密度和高氧平衡

IF 5

Defence Technology(防务技术) Pub Date : 2025-01-01 DOI: 10.1016/j.dt.2024.07.003

Jinya Zhang , Teng Fei , Jingwei Meng , Jinxiong Cai , Lei Zhang , Siping Pang , Chunlin He

{"title":"Taming of trinitromethyl-oxadiazole to access high density and high oxygen balance via a dual modulation strategy","authors":"Jinya Zhang , Teng Fei , Jingwei Meng , Jinxiong Cai , Lei Zhang , Siping Pang , Chunlin He","doi":"10.1016/j.dt.2024.07.003","DOIUrl":"10.1016/j.dt.2024.07.003","url":null,"abstract":"<div><div>Energetic compounds bearing the trinitromethyl group are garnering broad attraction as potential candidates for a new generation of high energy dense oxidizers. In this work, an effective dual modulation strategy involving both molecular isomerization and crystal morphology control was employed to design and optimize trinitromethyl-oxadiazole with improved comprehensive performance. Utilizing this dual strategy, 3,5-bis(trinitromethyl)-1,2,4-oxadiazole (<strong>3</strong>) was synthesized, resulting in the formation of two distinct crystal morphologies (needle and sheet) corresponding to two crystal forms (<strong>3-a</strong> and <strong>3-b</strong>). Encouragingly, while maintaining ultra-high oxygen balance (21.73%), <strong>3</strong> achieves impressive densities (1.97–1.98 g/cm<sup>3</sup>). To our knowledge, the density of 1.98 g/cm<sup>3</sup> for <strong>3-a</strong> sets a new record among that of nitrogen-rich monocyclic compounds. Notably, practical crystal morphology prediction was creatively introduced to guide the experimental crystallization conditions of <strong>3</strong>, increasing the impact sensitivity and friction sensitivity from 1 J to 80 N (<strong>3-a</strong>) to 10 J and 240 N (<strong>3-b</strong>), respectively. Additionally, the crystal structural analyses and theoretical calculations were conducted to elucidate the reasons of differences between <strong>3-a</strong> and <strong>3-b</strong> in density and stability. This work provides an efficient strategy to enhance performance of trinitromethyl derivatives, broadening the path and expanding the toolbox for energetic materials.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"43 ","pages":"Pages 142-149"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141700594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Honeycomb-spiderweb-inspired self-similar hybrid cellular structures for impact applications 用于冲击应用的蜂巢-蜘蛛网启发自相似混合蜂窝结构

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Defence Technology(防务技术) Pub Date : 2025-01-01 DOI: 10.1016/j.dt.2024.06.015

K. Tewari, M.K. Pandit, M.M. Mahapatra, P.R. Budarapu

{"title":"Honeycomb-spiderweb-inspired self-similar hybrid cellular structures for impact applications","authors":"K. Tewari, M.K. Pandit, M.M. Mahapatra, P.R. Budarapu","doi":"10.1016/j.dt.2024.06.015","DOIUrl":"10.1016/j.dt.2024.06.015","url":null,"abstract":"<div><div>Inspired by nature's self-similar designs, novel honeycomb-spiderweb based self-similar hybrid cellular structures are proposed here for efficient energy absorption in impact applications. The energy absorption is enhanced by optimizing the geometry and topology for a given mass. The proposed hybrid cellular structure is arrived after a thorough analysis of topologically enhanced self-similar structures. The optimized cell designs are rigorously tested considering dynamic loads involving crush and high-velocity bullet impact. Furthermore, the influence of thickness, radial connectivity, and order of patterning at the unit cell level are also investigated. The maximum crushing efficiency attained is found to be more than 95%, which is significantly higher than most existing traditional designs. Later on, the first and second-order hierarchical self-similar unit cell designs developed during crush analysis are used to prepare the cores for sandwich structures. Impact tests are performed on the developed sandwich structures using the standard 9-mm parabellum. The influence of multistaging on impact resistance is also investigated by maintaining a constant total thickness and mass of the sandwich structure. Moreover, in order to avoid layer-wise weak zones and hence, attain a uniform out-of-plane impact strength, off-setting the designs in each stage is proposed. The sandwich structures with first and second-order self-similar hybrid cores are observed to withstand impact velocities as high as 170 m/s and 270 m/s, respectively.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"43 ","pages":"Pages 182-200"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141711558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic properties of low-density expandable polystyrene concrete materials 低密度可膨胀聚苯乙烯混凝土材料的动态特性

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Defence Technology(防务技术) Pub Date : 2025-01-01 DOI: 10.1016/j.dt.2024.07.006

Jue Han , Hualin Fan

{"title":"Dynamic properties of low-density expandable polystyrene concrete materials","authors":"Jue Han , Hualin Fan","doi":"10.1016/j.dt.2024.07.006","DOIUrl":"10.1016/j.dt.2024.07.006","url":null,"abstract":"<div><div>Expanded polystyrene (EPS) concrete, known for its environmental friendliness, energy absorption capacity, and low impedance, has significant potential application in the fields of wave absorption and vibration reduction. This study designed and prepared EPS concrete materials with four levels of density. Quasi-static uniaxial compression and Split Hopkinson Pressure Bar (SHPB) impact tests were conducted to obtain stress-strain curves, elastic moduli, failure modes, energy absorptions, and strain rate effects of the EPS concrete under quasi-static and dynamic loading conditions. The influences of density on various performance indicators were analyzed. By combining the Zhu-Wang-Tang (ZWT) constitutive model with a modified elastic-brittle model, a modified dynamic constitutive model was proposed. The accuracy of the model was validated by the experimental data. The results indicate that the addition of EPS particles enhances the ductility of the EPS concrete. The EPS concrete has significant strain rate effect, which gets stronger as density increases. The modifiedconstitutive model accurately characterizes the dynamic stress-strain curves of the EPS concrete.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"43 ","pages":"Pages 94-108"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141844672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Autonomous sortie scheduling for carrier aircraft fleet under towing mode 拖曳模式下航母舰队的自主出动调度

IF 5

Defence Technology(防务技术) Pub Date : 2025-01-01 DOI: 10.1016/j.dt.2024.07.011

Zhilong Deng , Xuanbo Liu , Yuqi Dou , Xichao Su , Haixu Li , Lei Wang , Xinwei Wang

{"title":"Autonomous sortie scheduling for carrier aircraft fleet under towing mode","authors":"Zhilong Deng , Xuanbo Liu , Yuqi Dou , Xichao Su , Haixu Li , Lei Wang , Xinwei Wang","doi":"10.1016/j.dt.2024.07.011","DOIUrl":"10.1016/j.dt.2024.07.011","url":null,"abstract":"<div><div>Safe and efficient sortie scheduling on the confined flight deck is crucial for maintaining high combat effectiveness of the aircraft carrier. The primary difficulty exactly lies in the spatiotemporal coordination, i.e., allocation of limited supporting resources and collision-avoidance between heterogeneous dispatch entities. In this paper, the problem is investigated in the perspective of hybrid flow-shop scheduling problem by synthesizing the precedence, space and resource constraints. Specifically, eight processing procedures are abstracted, where tractors, preparing spots, catapults, and launching are virtualized as machines. By analyzing the constraints in sortie scheduling, a mixed-integer planning model is constructed. In particular, the constraint on preparing spot occupancy is improved to further enhance the sortie efficiency. The basic trajectory library for each dispatch entity is generated and a delayed strategy is integrated to address the collision-avoidance issue. To efficiently solve the formulated HFSP, which is essentially a combinatorial problem with tightly coupled constraints, a chaos-initialized genetic algorithm is developed. The solution framework is validated by the simulation environment referring to the Fort-class carrier, exhibiting higher sortie efficiency when compared to existing strategies. And animation of the simulation results is available at <span><span>www.bilibili.com/video/BV14t421A7Tt/</span><svg><path></path></svg></span>. The study presents a promising supporting technique for autonomous flight deck operation in the foreseeable future, and can be easily extended to other supporting scenarios, e.g., ammunition delivery and aircraft maintenance.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"43 ","pages":"Pages 1-12"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141850602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on the hazards of gas leakage and explosion in a full-scale residential building 关于大型住宅楼燃气泄漏和爆炸危害的研究

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Defence Technology(防务技术) Pub Date : 2025-01-01 DOI: 10.1016/j.dt.2024.06.014

Chengjun Yue, Li Chen, Zhan Li, Bin Feng, Ruizhi Xu

{"title":"Research on the hazards of gas leakage and explosion in a full-scale residential building","authors":"Chengjun Yue, Li Chen, Zhan Li, Bin Feng, Ruizhi Xu","doi":"10.1016/j.dt.2024.06.014","DOIUrl":"10.1016/j.dt.2024.06.014","url":null,"abstract":"<div><div>The gas explosion in residential building has always been a highly concerned problem. Explosions in homogeneous mixtures have been extensively studied. However, mixtures are often inhomogeneous in the practical scenarios due to the differences in the densities of methane and air. In order to investigate the effects of gas explosions in inhomogeneous mixtures, experimental studies involving gas leakage and explosion are conducted in a full-scale residential building to reproduce the process of gas explosion. By fitting the dimensionless buoyancy as a function of dimensionless height and dimensionless time, a distribution model of gas in large-scale spaces is established, and the mechanism of inhomogeneous distribution of methane is also be revealed. Furthermore, the stratified reconstruction method (SRM) is introduced for efficiently setting up inhomogeneous concentration fields in FLACS. The simulation results highlight that for the internal overpressure, the distribution of methane has no effect on the first overpressure peak (ΔP1), while it significantly influences the subsequent overpressure peak (ΔP2), and the maximum difference between the overpressure of homogeneous and inhomogeneous distribution is 174.3%. Moreover, the initial concentration distribution also has a certain impact on the external overpressure.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"43 ","pages":"Pages 168-181"},"PeriodicalIF":5.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141572580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic analysis of the tethered satellite system considering uncertain but bounded parameters 考虑不确定但有约束的参数的系留卫星系统动态分析

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Defence Technology(防务技术) Pub Date : 2024-12-01 DOI: 10.1016/j.dt.2024.06.017

Xin Jiang , Zhengfeng Bai

引用次数: 0

Analytical game strategies for active UAV defense considering response delays 考虑响应延迟的主动无人机防御分析博弈策略

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Defence Technology(防务技术) Pub Date : 2024-12-01 DOI: 10.1016/j.dt.2024.07.001

Xiaopeng Gong , Wanchun Chen , Wengui Lei , Jinyang Wang , Zhongyuan Chen , Yunyun Li

{"title":"Analytical game strategies for active UAV defense considering response delays","authors":"Xiaopeng Gong , Wanchun Chen , Wengui Lei , Jinyang Wang , Zhongyuan Chen , Yunyun Li","doi":"10.1016/j.dt.2024.07.001","DOIUrl":"10.1016/j.dt.2024.07.001","url":null,"abstract":"<div><div>In the realm of aerial warfare, the protection of Unmanned Aerial Vehicles (UAVs) against adversarial threats is crucial. In order to balance the impact of response delays and the demand for onboard applications, this paper derives three analytical game strategies for the active defense of UAVs from differential game theory, accommodating the first-order dynamic delays. The targeted UAV executes evasive maneuvers and launches a defending missile to intercept the attacking missile, which constitutes a UAV-Missile-Defender (UMD) three-body game problem. We explore two distinct operational paradigms: the first involves the UAV and the defender working collaboratively to intercept the incoming threat, while the second prioritizes UAV self-preservation, with independent maneuvering away from potentially sacrificial engagements. Starting with model linearization and order reduction, the Collaborative Interception Strategy (CIS) is first derived via a linear quadratic differential game formulation. Building upon CIS, we further explore two distinct strategies: the Informed Defender Interception Strategy (IDIS), which utilizes UAV maneuvering information, and the Unassisted Defender Interception Strategy (UDIS), which does not rely on UAV maneuvering information. Additionally, we investigate the conditions for the existence of saddle point solutions and their relationship with vehicle maneuverability and response agility. The simulations demonstrate the effectiveness and advantages of the proposed strategies.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 191-210"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141695518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Finite element approach for free vibration and transient response of bi-directional functionally graded sandwich porous skew-plates with variable thickness subjected to blast load

IF 5

Defence Technology(防务技术) Pub Date : 2024-12-01 DOI: 10.1016/j.dt.2024.08.022

Hong Nguyen Thi

{"title":"Finite element approach for free vibration and transient response of bi-directional functionally graded sandwich porous skew-plates with variable thickness subjected to blast load","authors":"Hong Nguyen Thi","doi":"10.1016/j.dt.2024.08.022","DOIUrl":"10.1016/j.dt.2024.08.022","url":null,"abstract":"<div><div>At the first time, the finite element method was used to model and analyze the free vibration and transient response of non-uniform thickness bi-directional functionally graded sandwich porous (BFGSP) skew plates. The whole BFGSP skew-plates is placed on a variable visco-elastic foundation (VEF) in the hygro-thermal environment and subjected to the blast load. The BFGSP skew-plate thickness is permitted to vary non-linearly over both the length and width of the skew-plate, thereby faithfully representing the real behavior of the structure itself. The analysis is based on a four-node planar quadrilateral element with eight degrees of freedom per node, which is approximated using Lagrange Q<sub>4</sub> shape function and C<sup>1</sup> level non-conforming Hermite shape function based on refined higher-order shear deformation plate theory. The forced vibration parameters of the non-uniform thickness BFGSP skew-plate are fully determined using Hamilton's principle and the Newmark-β direct integration technique. Accuracy of the calculation program is validated by comparing its numerical results with those from reputable sources. Furthermore, a thorough assessment is conducted to determine the impact of various parameters on the free and forced vibration responses of the non-uniform thickness BFGSP skew-plate. The findings of the paper may be used in the development of civil and military structures in situations that are prone to exceptional forces, such as explosions and impacts load.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 83-104"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced damage mechanism of reinforced concrete targets impacted by reactive PELE: An analytical model and experimental validation 钢筋混凝土目标受反应性 PELE 影响的强化破坏机制：分析模型与实验验证

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Defence Technology(防务技术) Pub Date : 2024-12-01 DOI: 10.1016/j.dt.2024.07.004

Jiahao Zhang, Mengmeng Guo, Sheng Zhou, Chao Ge, Pengwan Chen, Qingbo Yu

{"title":"Enhanced damage mechanism of reinforced concrete targets impacted by reactive PELE: An analytical model and experimental validation","authors":"Jiahao Zhang, Mengmeng Guo, Sheng Zhou, Chao Ge, Pengwan Chen, Qingbo Yu","doi":"10.1016/j.dt.2024.07.004","DOIUrl":"10.1016/j.dt.2024.07.004","url":null,"abstract":"<div><div>Compared with PELE with inert fillings such as polyethylene and nylon, reactive PELE (RPELE) shows excellent damage effects when impacting concrete targets due to the filling deflagration reaction. In present work, an analytical model describing the jacket deformation and concrete target damage impacted by RPELE was presented, in which the radial rarefaction and filling deflagration reaction were considered. The impact tests of RPELE on concrete target in the 592–1012 m/s were carried out to verify the analytical model. Based on the analytical model, the angle-length evolution mechanism of the jacket bending-curling deformation was revealed, and the concrete target damage was further analyzed. One can find out that the average prediction errors of the front crater, opening and back crater are 6.8%, 8.5% and 7.1%, respectively. Moreover, the effects of radial rarefaction and deflagration were discussed. It was found that the neglect of radial rarefaction overestimates the jacket deformation and concrete target damage, while the deflagration reaction of filling increases the diameter of the front crater, opening and back crater by 25.4%, 24.3% and 31.1%, respectively. The research provides a valuable reference for understanding and predicting the jacket deformation and concrete target damage impacted by RPELE.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 12-30"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141709334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Linear-quadratic and norm-bounded combined differential game guidance scheme with obstacle avoidance for attacking defended aircraft in three-player engagement 线性-二次方和规范-有界组合微分博弈制导方案，用于在三人交战中攻击防御飞机并避开障碍物

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Defence Technology(防务技术) Pub Date : 2024-12-01 DOI: 10.1016/j.dt.2024.06.018

Xintao Wang , Ming Yang , Songyan Wang , Mingzhe Hou , Tao Chao

{"title":"Linear-quadratic and norm-bounded combined differential game guidance scheme with obstacle avoidance for attacking defended aircraft in three-player engagement","authors":"Xintao Wang , Ming Yang , Songyan Wang , Mingzhe Hou , Tao Chao","doi":"10.1016/j.dt.2024.06.018","DOIUrl":"10.1016/j.dt.2024.06.018","url":null,"abstract":"<div><div>A differential game guidance scheme with obstacle avoidance, based on the formulation of a combined linear quadratic and norm-bounded differential game, is designed for a three-player engagement scenario, which includes a pursuer, an interceptor, and an evader. The confrontation between the players is divided into four phases (P1–P4) by introducing the switching time, and proposing different guidance strategies according to the phase where the static obstacle is located: the linear quadratic game method is employed to devise the guidance scheme for the energy optimization when the obstacle is located in the P1 and P3 stages; the norm-bounded differential game guidance strategy is presented to satisfy the acceleration constraint under the circumstance that the obstacle is located in the P2 and P4 phases. Furthermore, the radii of the static obstacle and the interceptor are taken as the design parameters to derive the combined guidance strategy through the dead-zone function, which guarantees that the pursuer avoids the static obstacle, and the interceptor, and attacks the evader. Finally, the nonlinear numerical simulations verify the performance of the game guidance strategy.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 136-155"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141694579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0