Pub Date : 2024-12-01DOI: 10.1016/j.dt.2024.06.012
Zehao Wang , Pengfei Xue , Qingxuan Zeng , Mingyu Li
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 cm3. 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.
{"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":"10.1016/j.dt.2024.06.012","url":null,"abstract":"<div><div>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<sup>3</sup>. 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.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 125-135"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784749","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}
Pub Date : 2024-12-01DOI: 10.1016/j.dt.2024.08.006
Xinli Ye , Pengyi Xu , Hao Yu , Shan Li , Xiaomin Ma , Wei Xu , Junxiong Zhang
SiC aerogel presents several advantageous features like lightweight and high temperature resistance when applied as microwave absorbing material. In this paper, SiC aerogel was prepared eventually followed by the sol-gel and carbonization reduction process. The results showed that the effective electromagnetic microwave absorption capacity of SiC aerogel was highly increased after being pyrolyzed at 1500 °C, which presented a minimum reflection loss value of −57.80 dB at 3.10 mm and 9.86 GHz. Besides, the electromagnetic parameters of SiC aerogel with different paraffin ratios were discussed as well as the varying electromagnetic microwave absorption performances. The minimum reflection loss value first rose then fell as the SiC/paraffin ratio increased, which demonstrated the importance of SiC content. This study establishes the theoretical foundation for the subsequent functional application of SiC aerogel.
{"title":"Preparation and microwave absorption performance of SiC aerogel via sol-gel and carbonization reduction process","authors":"Xinli Ye , Pengyi Xu , Hao Yu , Shan Li , Xiaomin Ma , Wei Xu , Junxiong Zhang","doi":"10.1016/j.dt.2024.08.006","DOIUrl":"10.1016/j.dt.2024.08.006","url":null,"abstract":"<div><div>SiC aerogel presents several advantageous features like lightweight and high temperature resistance when applied as microwave absorbing material. In this paper, SiC aerogel was prepared eventually followed by the sol-gel and carbonization reduction process. The results showed that the effective electromagnetic microwave absorption capacity of SiC aerogel was highly increased after being pyrolyzed at 1500 °C, which presented a minimum reflection loss value of −57.80 dB at 3.10 mm and 9.86 GHz. Besides, the electromagnetic parameters of SiC aerogel with different paraffin ratios were discussed as well as the varying electromagnetic microwave absorption performances. The minimum reflection loss value first rose then fell as the SiC/paraffin ratio increased, which demonstrated the importance of SiC content. This study establishes the theoretical foundation for the subsequent functional application of SiC aerogel.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 73-82"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189177","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}
Pub Date : 2024-12-01DOI: 10.1016/j.dt.2024.08.005
Pavel Hanus , Milan Pecanac , Mirjana Trivkovic , Savo Bojić , Sebastian Balos
Intermetallic aluminide compounds possess several potential advantages compared to alloyed steels, like enhanced oxidation resistance, lower density and the omittance of critical raw materials. Iron aluminides, compared to other transition metal–aluminides of TM3-Al type, although having a higher density compared to titan-aluminides, have a lower density compared to nickel-aluminides, but also a higher ductility than both alternatives, making this material potentially effective in ballistic protection application. Density–wise, this material may be a worthy alternative to armour steels, which was the aim of this study. Two materials, Fe3Al intermetallic compound (F3A-C) and Armox 500 armour steel were ballistically tested against tungsten-carbide (WC) armour-piercing ammunition, in accordance with STANAG 4569. After ballistic testing, microhardness and metallographic testing were performed, revealing differences in strain hardening, crack propagation mode and exit hole morphology. F3A-C ballistic resistance is similar to that of armour steel, in spite of the lower tensile and impact mechanical properties, relying on a considerably higher strain hardening rate, thermal properties and a lower density.
{"title":"Comparison of iron aluminide Fe3Al with armour steel in ballistic behaviour","authors":"Pavel Hanus , Milan Pecanac , Mirjana Trivkovic , Savo Bojić , Sebastian Balos","doi":"10.1016/j.dt.2024.08.005","DOIUrl":"10.1016/j.dt.2024.08.005","url":null,"abstract":"<div><div>Intermetallic aluminide compounds possess several potential advantages compared to alloyed steels, like enhanced oxidation resistance, lower density and the omittance of critical raw materials. Iron aluminides, compared to other transition metal–aluminides of TM<sub>3</sub>-Al type, although having a higher density compared to titan-aluminides, have a lower density compared to nickel-aluminides, but also a higher ductility than both alternatives, making this material potentially effective in ballistic protection application. Density–wise, this material may be a worthy alternative to armour steels, which was the aim of this study. Two materials, Fe<sub>3</sub>Al intermetallic compound (F3A-C) and Armox 500 armour steel were ballistically tested against tungsten-carbide (WC) armour-piercing ammunition, in accordance with STANAG 4569. After ballistic testing, microhardness and metallographic testing were performed, revealing differences in strain hardening, crack propagation mode and exit hole morphology. F3A-C ballistic resistance is similar to that of armour steel, in spite of the lower tensile and impact mechanical properties, relying on a considerably higher strain hardening rate, thermal properties and a lower density.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 183-190"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104186","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}
Pub Date : 2024-12-01DOI: 10.1016/j.dt.2024.07.012
Alexandra Zabala-López , Mario Linares-Vásquez , Sonia Haiduc , Yezid Donoso
In a time characterized by the availability of vast amounts of data, the effective utilization of information is critical for timely decision-making in military operations. However, processing large amounts of data requires computational resources and time. Therefore, decision makers have used data-centric technologies to take advantage of public and private data sources to support military operations. This survey explores the integration and application of data-centric technologies, such as data analytics, data science, and machine learning, to optimize decision-making workflows within military contexts supporting the deployment of military assets and resources. To address the information gap, this article presents a literature review, specifically a survey. Our survey examines the use of the mentioned technologies to process and analyze information that contributes to the phases of situational awareness, and planning in military environments. We then introduce a taxonomy of the approaches associated with implementing these technologies in military scenarios. Furthermore, we discuss relevant factors for the seamless integration of data-centric technologies into military decision-making processes, and reveal the importance of specialized personnel, architectures, and cybersecurity issues in the task of developing prototypes and models. The findings of this paper aim to provide valuable insights for military institutions, offering a deeper understanding of the use of data-centric technologies as innovative practices to enhance the effectiveness of military decision-making.
{"title":"A survey of data-centric technologies supporting decision-making before deploying military assets","authors":"Alexandra Zabala-López , Mario Linares-Vásquez , Sonia Haiduc , Yezid Donoso","doi":"10.1016/j.dt.2024.07.012","DOIUrl":"10.1016/j.dt.2024.07.012","url":null,"abstract":"<div><div>In a time characterized by the availability of vast amounts of data, the effective utilization of information is critical for timely decision-making in military operations. However, processing large amounts of data requires computational resources and time. Therefore, decision makers have used data-centric technologies to take advantage of public and private data sources to support military operations. This survey explores the integration and application of data-centric technologies, such as data analytics, data science, and machine learning, to optimize decision-making workflows within military contexts supporting the deployment of military assets and resources. To address the information gap, this article presents a literature review, specifically a survey. Our survey examines the use of the mentioned technologies to process and analyze information that contributes to the phases of situational awareness, and planning in military environments. We then introduce a taxonomy of the approaches associated with implementing these technologies in military scenarios. Furthermore, we discuss relevant factors for the seamless integration of data-centric technologies into military decision-making processes, and reveal the importance of specialized personnel, architectures, and cybersecurity issues in the task of developing prototypes and models. The findings of this paper aim to provide valuable insights for military institutions, offering a deeper understanding of the use of data-centric technologies as innovative practices to enhance the effectiveness of military decision-making.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 226-246"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141846771","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}
Pub Date : 2024-12-01DOI: 10.1016/j.dt.2024.07.002
Yang Wang , Junyong Tao , Xiaoke Zhang , Guanghan Bai , Yunan Zhang
With continuous growth in scale, topology complexity, mission phases, and mission diversity, challenges have been placed for efficient capability evaluation of modern combat systems. Aiming at the problems of insufficient mission consideration and single evaluation dimension in the existing evaluation approaches, this study proposes a mission-oriented capability evaluation method for combat systems based on operation loop. Firstly, a combat network model is given that takes into account the capability properties of combat nodes. Then, based on the transition matrix between combat nodes, an efficient algorithm for operation loop identification is proposed based on the Breadth-First Search. Given the mission-capability satisfaction of nodes, the effectiveness evaluation indexes for operation loops and combat network are proposed, followed by node importance measure. Through a case study of the combat scenario involving space-based support against surface ships under different strategies, the effectiveness of the proposed method is verified. The results indicated that the ROI-priority attack method has a notable impact on reducing the overall efficiency of the network, whereas the O-L betweenness-priority attack is more effective in obstructing the successful execution of enemy attack missions.
{"title":"Mission-oriented capability evaluation for combat network based on operation loops","authors":"Yang Wang , Junyong Tao , Xiaoke Zhang , Guanghan Bai , Yunan Zhang","doi":"10.1016/j.dt.2024.07.002","DOIUrl":"10.1016/j.dt.2024.07.002","url":null,"abstract":"<div><div>With continuous growth in scale, topology complexity, mission phases, and mission diversity, challenges have been placed for efficient capability evaluation of modern combat systems. Aiming at the problems of insufficient mission consideration and single evaluation dimension in the existing evaluation approaches, this study proposes a mission-oriented capability evaluation method for combat systems based on operation loop. Firstly, a combat network model is given that takes into account the capability properties of combat nodes. Then, based on the transition matrix between combat nodes, an efficient algorithm for operation loop identification is proposed based on the Breadth-First Search. Given the mission-capability satisfaction of nodes, the effectiveness evaluation indexes for operation loops and combat network are proposed, followed by node importance measure. Through a case study of the combat scenario involving space-based support against surface ships under different strategies, the effectiveness of the proposed method is verified. The results indicated that the ROI-priority attack method has a notable impact on reducing the overall efficiency of the network, whereas the O-L betweenness-priority attack is more effective in obstructing the successful execution of enemy attack missions.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 156-175"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141706459","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}
Pub Date : 2024-12-01DOI: 10.1016/j.dt.2024.07.014
Jiqing Luo , Husheng Fang , Yue Zhong , Jing Zhang , Shengli Song
In this paper, the fixed-time time-varying formation of heterogeneous multi-agent systems (MASs) based on tracking error observer under denial-of-service (DoS) attacks is investigated. Firstly, the dynamic pinning strategy is used to reconstruct the communication channel for the system that suffers from DoS attacks to prevent the discontinuous transmission information of the communication network from affecting MASs formation. Then, considering that the leader state is not available to each follower under DoS attacks, a fixed-time distributed observer without velocity information is constructed to estimate the tracking error between followers and the leader. Finally, adaptive radial basis function neural network (RBFNN) is used to approximate the unknown ensemble disturbances in the system, and the fixed-time time-varying formation scheme is designed with the constructed observer. The effectiveness of the proposed control algorithm is demonstrated by the numerical simulation.
本文研究了在拒绝服务（DoS）攻击下，基于跟踪误差观测器的异构多代理系统（MAS）的定时时变形成。首先，采用动态销钉策略为遭受 DoS 攻击的系统重建通信信道，防止通信网络传输信息不连续影响 MAS 的形成。然后，考虑到在 DoS 攻击下每个跟随者无法获得领导者的状态，构建了一个没有速度信息的固定时间分布式观测器来估计跟随者与领导者之间的跟踪误差。最后，使用自适应径向基函数神经网络（RBFNN）来近似系统中的未知集合干扰，并利用构建的观测器设计定时时变编队方案。数值仿真证明了所提控制算法的有效性。
{"title":"Research on fixed-time time-varying formation of heterogeneous multi-agent systems based on tracking error observer under DoS attacks","authors":"Jiqing Luo , Husheng Fang , Yue Zhong , Jing Zhang , Shengli Song","doi":"10.1016/j.dt.2024.07.014","DOIUrl":"10.1016/j.dt.2024.07.014","url":null,"abstract":"<div><div>In this paper, the fixed-time time-varying formation of heterogeneous multi-agent systems (MASs) based on tracking error observer under denial-of-service (DoS) attacks is investigated. Firstly, the dynamic pinning strategy is used to reconstruct the communication channel for the system that suffers from DoS attacks to prevent the discontinuous transmission information of the communication network from affecting MASs formation. Then, considering that the leader state is not available to each follower under DoS attacks, a fixed-time distributed observer without velocity information is constructed to estimate the tracking error between followers and the leader. Finally, adaptive radial basis function neural network (RBFNN) is used to approximate the unknown ensemble disturbances in the system, and the fixed-time time-varying formation scheme is designed with the constructed observer. The effectiveness of the proposed control algorithm is demonstrated by the numerical simulation.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"42 ","pages":"Pages 211-225"},"PeriodicalIF":5.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188970","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}
Pub Date : 2024-11-01DOI: 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。
{"title":"An isogeometric analysis approach for dynamic response of doubly-curved magneto electro elastic composite shallow shell subjected to blast loading","authors":"Pham Hoang Tu , Tran Van Ke , Vu Khac Trai , Le Hoai","doi":"10.1016/j.dt.2024.06.005","DOIUrl":"10.1016/j.dt.2024.06.005","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"41 ","pages":"Pages 159-180"},"PeriodicalIF":5.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141413316","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}
Pub Date : 2024-11-01DOI: 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.
{"title":"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","authors":"Lei Yang, Zhenqi Zhang, Wei Du, Jinshan Li, Qing Ma","doi":"10.1016/j.dt.2024.06.008","DOIUrl":"10.1016/j.dt.2024.06.008","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"41 ","pages":"Pages 13-21"},"PeriodicalIF":5.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141577788","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}
Pub Date : 2024-11-01DOI: 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.
{"title":"Ti/WO3, a nanothermite for special purposes: An experimental study","authors":"Mateusz Polis , Agnieszka Stolarczyk , Konrad Szydlo , Tomasz Jarosz , Marcin Procek , Sebastian Slawski , Lukasz Hawelek","doi":"10.1016/j.dt.2024.06.010","DOIUrl":"10.1016/j.dt.2024.06.010","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"41 ","pages":"Pages 1-12"},"PeriodicalIF":5.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141572564","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}
Pub Date : 2024-11-01DOI: 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.
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