Defence Technology最新文献_第2页

Research on fixed-time time-varying formation of heterogeneous multi-agent systems based on tracking error observer under DoS attacks DoS 攻击下基于跟踪误差观测器的异构多代理系统定时时变编队研究

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-07-30 DOI: 10.1016/j.dt.2024.07.014

Jiqing Luo, Husheng Fang, Yue Zhong, Jing Zhang, Shengli Song

引用次数: 0

Investigation on the exploding foil initiators ignition enhanced by explosion-electricity coupling 通过爆炸-电耦合增强爆炸箔引发器点火的研究

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-06-26 DOI: 10.1016/j.dt.2024.06.013

Songmao Zhao, Haotian Jian, Ke Wang, Zheng Ning, Peng Zhu, Ruiqi Shen

{"title":"Investigation on the exploding foil initiators ignition enhanced by explosion-electricity coupling","authors":"Songmao Zhao, Haotian Jian, Ke Wang, Zheng Ning, Peng Zhu, Ruiqi Shen","doi":"10.1016/j.dt.2024.06.013","DOIUrl":"https://doi.org/10.1016/j.dt.2024.06.013","url":null,"abstract":"Explosion-electricity coupling (EEC) is a technical method to induce electric energy into the plasma material produced by explosion to improve the output of explosion. Exploding foil initiator (EFI) which could produce plasma during electric explosion can serve as a good carrier for studying the EEC. To investigate the enhancement ability and mechanism of EEC in EFI ignition performance, a kind of EFI chips which could realize the EEC effect was designed and fabricated to observe the characteristics of current and voltage, flyer and plasma temperature during Boron Potassium Nitrate (BPN) ignition of the EFI. It was found that the EEC could enhance EFI ignition in terms of energy utilization, ignition contact surface, and high-temperature sustainability of plasma: firstly, the EEC prolonged the late time discharge (LTD) phase of the electric explosion, making the energy of capacitor effectively utilized; secondly, the EEC could create a larger area of ignition contact surface; last of all, the EEC effect enhanced its high-temperature sustainability by sustaining continuous energy input to plasma. It also was found that the ignition voltage of BPN could be reduced by nearly 600 V under the condition of 0.4 μF capacitance. The research has successfully combined EEC with EFI, revealing the behavioral characteristics of EEC and demonstrating its effective enhancement of EFI ignition. It introduces a new approach to improving EFI output, which is conducive to low-energy ignition of EFI, and expected to take the ignition technology of EFI to a new level.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"68 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design, fabrication and performance test of an integrated exploding foil initiator system 集成爆炸箔引发器系统的设计、制造和性能测试

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-06-22 DOI: 10.1016/j.dt.2024.06.012

Zehao Wang, Pengfei Xue, Qingxuan Zeng, Mingyu Li

{"title":"Design, fabrication and performance test of an integrated exploding foil initiator system","authors":"Zehao Wang, Pengfei Xue, Qingxuan Zeng, Mingyu Li","doi":"10.1016/j.dt.2024.06.012","DOIUrl":"https://doi.org/10.1016/j.dt.2024.06.012","url":null,"abstract":"The integration method of exploding foil initiator system (EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades. In order to lower the firing voltage below 1 kV, an integrated EFIs with enhanced energy efficiency was designed. Corresponding exploding foil initiator chips were fabricated in batch via micro electromechanical systems technology by integrating a unified foil, a flyer layer and a barrel on a glass substrate successively, meanwhile its package of the whole system was proposed at a volume of 2.194 cm. The structural parameters were determined by predicted performance including flyer velocity, impact behavior and conduction property via the proposed theoretical models and the static electric field simulation. As expect, this integrated EFIs exhibited excellent functions, which could accelerate the flyer to a terminal velocity over 4 km/s and preeminently initiate HNS-IV pellet at a circuit of 0.24 μF/0.9 kV. Furthermore, the theoretical design, fabrication and performance test have been all included to validate the feasibility of this integrated EFIs that was beneficial for its commercial development in the future.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"771 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","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

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-06-22 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":"https://doi.org/10.1016/j.dt.2024.06.014","url":null,"abstract":"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.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"87 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141572580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A comprehensive survey of cyberattacks on EVs: Research domains, attacks, defensive mechanisms, and verification methods 电动汽车网络攻击综合调查：研究领域、攻击、防御机制和验证方法

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-06-18 DOI: 10.1016/j.dt.2024.06.009

Tawfiq Aljohani, Abdulaziz Almutairi

{"title":"A comprehensive survey of cyberattacks on EVs: Research domains, attacks, defensive mechanisms, and verification methods","authors":"Tawfiq Aljohani, Abdulaziz Almutairi","doi":"10.1016/j.dt.2024.06.009","DOIUrl":"https://doi.org/10.1016/j.dt.2024.06.009","url":null,"abstract":"With the continuous development of transportation electrification, the cybersecurity of energy infrastructure has become increasingly prominent. Explicitly, EVs resemble a significant tool to carryout cyberattacks since EVs are not only seen as dynamic loads but also as mobile energy sources that establish two-way communications with several players in the grid. This taxonomy aims to provide a comprehensive overview of cyberattacks against EVs from four distinct perspectives. The first is the research domains of EVs application, which investigates the different fields of research related to the development and application of EVs and how they are susceptible to cyber threats. The second is the CIA-based attacks, which examines the threats to the confidentiality, integrity, and availability of EVs' sensitive information and critical systems. The third taxonomy discusses the countermeasures and defensive mechanisms to secure the EVs against cyberattacks, including preventive measures, detection algorithms, response strategy, and recovery techniques. The fourth taxonomy is the verification and validation methodologies, which explores the software tools and hardware testbeds used to test and evaluate the security of EVs against cyber threats. Finally, this taxonomy presents an understanding of the current state of cyberattacks against EVs and serves as a valuable resource for researchers and practitioners in the fields of cybersecurity and electric mobility.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"32 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141948365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synergistic effect of nitrocellulose coating on structural and reactivity stabilization of ammonium nitrate oxidizer 硝化纤维素涂层对硝酸铵氧化剂结构和反应活性稳定化的协同效应

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-04-30 DOI: 10.1016/j.dt.2024.04.017

Amir Abdelaziz, Djalal Trache, Ahmed Fouzi Tarchoun, Hani Boukeciat, Yash Pal, Sourbh Thakur, Weiqiang Pang, Thomas M. Klapötke

{"title":"Synergistic effect of nitrocellulose coating on structural and reactivity stabilization of ammonium nitrate oxidizer","authors":"Amir Abdelaziz, Djalal Trache, Ahmed Fouzi Tarchoun, Hani Boukeciat, Yash Pal, Sourbh Thakur, Weiqiang Pang, Thomas M. Klapötke","doi":"10.1016/j.dt.2024.04.017","DOIUrl":"https://doi.org/10.1016/j.dt.2024.04.017","url":null,"abstract":"The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate (AN) particles utilizing a microencapsulation technique, which involves solvent/non-solvent in which nitrocellulose (NC) has been employed as a coating agent. The SEM micrographs revealed distinct features of both pure AN and NC, contrasting with the irregular granular surface topography of the coated AN particles, demonstrating the adherence of NC on the AN surface. Structural analysis infrared spectroscopy (IR) demonstrated a successful association of AN and NC, with slight shifts observed in IR bands indicating interfacial interactions. Powder X-ray Diffraction (PXRD) analysis further elucidated the structural changes induced by the coating process, revealing that the NC coating altered the crystallization pattern of its pure form. Thermal analysis demonstrates distinct profiles for pure and coated AN, for which the coated sample exhibits a temperature increase and an enthalpy decrease of the room temperature allotropic transition by 6 °C, and 36%, respectively. Furthermore, the presence of NC coating alters the intermolecular forces within the composite system, leading to a reduction in melting enthalpy of coated AN by ∼39% compared to pure AN. The thermal decomposition analysis shows a two-step thermolysis process for coated AN, with a significant increase in the released heat by about 78% accompanied by an increase in the activation barrier of NC and AN thermolysis, demonstrating a stabilized reactivity of the AN-NC particles. These findings highlight the synergistic effect of NC coating on AN particles, which contributed to a structural and reactive stabilization of both AN and NC, proving the potential application of NC-coated AN as a strategically advantageous oxidizer in composite solid propellant formulations.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"19 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141197773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Discovering causal models for structural, construction and defense-related engineering phenomena 发现结构、建筑和国防相关工程现象的因果模型

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-04-27 DOI: 10.1016/j.dt.2024.04.007

M.Z. Naser

{"title":"Discovering causal models for structural, construction and defense-related engineering phenomena","authors":"M.Z. Naser","doi":"10.1016/j.dt.2024.04.007","DOIUrl":"https://doi.org/10.1016/j.dt.2024.04.007","url":null,"abstract":"Causality, the science of cause and effect, has made it possible to create a new family of models. Such models are often referred to as causal models. Unlike those of mathematical, numerical, empirical, or machine learning (ML) nature, causal models hope to tie the cause(s) to the effect(s) pertaining to a phenomenon (i.e., data generating process) through causal principles. This paper presents one of the first works at creating causal models in the area of structural and construction engineering. To this end, this paper starts with a brief review of the principles of causality and then adopts four causal discovery algorithms, namely, PC (Peter-Clark), FCI (fast causal inference), GES (greedy equivalence search), and GRaSP (greedy relaxation of the sparsest permutation), have been used to examine four phenomena, including predicting the load-bearing capacity of axially loaded members, fire resistance of structural members, shear strength of beams, and resistance of walls against impulsive (blast) loading. Findings from this study reveal the possibility and merit of discovering complete and partial causal models. Finally, this study also proposes two simple metrics that can help assess the performance of causal discovery algorithms.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"31 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141197772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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

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

Hao Xue, Qiang Zhou, Chuan Xiao, Guangyan Huang

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

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

Ya Yang, Xiangzhen Kong, Qin Fang

{"title":"Non-dimensional analysis on blast wave propagation in foam concrete: Minimum thickness to avoid stress enhancement","authors":"Ya Yang, Xiangzhen Kong, Qin Fang","doi":"10.1016/j.dt.2023.12.005","DOIUrl":"https://doi.org/10.1016/j.dt.2023.12.005","url":null,"abstract":"<p>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.</p>","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"34 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139029879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0