Defence Technology最新文献

Characterization of combined blast- and fragments-induced synergetic damage in polyurea coated liquid-filled container 聚脲涂层充液容器中爆炸和碎片共同诱发的协同损伤的特征

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-21 DOI: 10.1016/j.dt.2024.08.009

Chen Tao, Chong Ji, Xin Wang, Juan Gu, Yuting Wang, Changxiao Zhao

{"title":"Characterization of combined blast- and fragments-induced synergetic damage in polyurea coated liquid-filled container","authors":"Chen Tao, Chong Ji, Xin Wang, Juan Gu, Yuting Wang, Changxiao Zhao","doi":"10.1016/j.dt.2024.08.009","DOIUrl":"https://doi.org/10.1016/j.dt.2024.08.009","url":null,"abstract":"Liquid-filled containers (LFC) are widely used to store and transport petroleum, chemical reagents, and other resources. As an important target of military strikes and terrorist bombings, LFC are vulnerable to blast waves and fragments. To explore the protective effect of polyurea elastomer on LFC, the damage characteristics of polyurea coated liquid-filled container (PLFC) under the combined loading of blast shock wave and fragments were studied experimentally. The microstructure of the polyurea layer was observed by scanning electron microscopy, and the fracture and self-healing phenomena were analyzed. The simulation approach was used to explain the combined blast- and fragments-induced on the PLFC in detail. Finally, the effects of shock wave and fragment alone and in combination on the damage of PLFC were comprehensively compared. Results showed that the polyurea reduces the perforation rate of the fragment to the LFC, and the self-healing phenomenon could also reduce the liquid loss rate inside the container. The polyurea reduces the degree of depression in the center of the LFC, resulting in a decrease in the distance between adjacent fragments penetrating the LFC, and an increase in the probability of transfixion and fracture between holes. Under the close-in blast, the detonation shock wave reached the LFC before the fragment. Polyurea does not all have an enhanced effect on the protection of LFC. The presence of internal water enhances the anti-blast performance of the container, and the hydrodynamic ram (HRAM) formed by the fragment impacting the water aggravated the plastic deformation of the container. The combined action has an enhancement effect on the deformation of the LFC. The depth of the container depression was 27% higher than that of the blast shock wave alone; thus, it cannot be simply summarized as linear superposition.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"72 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189173","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

FedCLCC: A personalized federated learning algorithm for edge cloud collaboration based on contrastive learning and conditional computing FedCLCC：基于对比学习和条件计算的边缘云协作个性化联合学习算法

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-21 DOI: 10.1016/j.dt.2024.08.015

Kangning Yin, Xinhui Ji, Yan Wang, Zhiguo Wang

{"title":"FedCLCC: A personalized federated learning algorithm for edge cloud collaboration based on contrastive learning and conditional computing","authors":"Kangning Yin, Xinhui Ji, Yan Wang, Zhiguo Wang","doi":"10.1016/j.dt.2024.08.015","DOIUrl":"https://doi.org/10.1016/j.dt.2024.08.015","url":null,"abstract":"Federated learning (FL) is a distributed machine learning paradigm for edge cloud computing. FL can facilitate data-driven decision-making in tactical scenarios, effectively addressing both data volume and infrastructure challenges in edge environments. However, the diversity of clients in edge cloud computing presents significant challenges for FL. Personalized federated learning (pFL) received considerable attention in recent years. One example of pFL involves exploiting the global and local information in the local model. Current pFL algorithms experience limitations such as slow convergence speed, catastrophic forgetting, and poor performance in complex tasks, which still have significant shortcomings compared to the centralized learning. To achieve high pFL performance, we propose FedCLCC: Federated Contrastive Learning and Conditional Computing. The core of FedCLCC is the use of contrastive learning and conditional computing. Contrastive learning determines the feature representation similarity to adjust the local model. Conditional computing separates the global and local information and feeds it to their corresponding heads for global and local handling. Our comprehensive experiments demonstrate that FedCLCC outperforms other state-of-the-art FL algorithms.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"13 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189172","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

Experimental investigation on the anti-detonation performance of composite structure containing foam geopolymer backfill material 含泡沫土工聚合物回填材料的复合结构抗爆性能实验研究

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-19 DOI: 10.1016/j.dt.2024.08.011

Hang Zhou, Hujun Li, Zhen Wang, Dongming Yan, Wenxin Wang, Guokai Zhang, Zirui Cheng, Song Sun, Mingyang Wang

{"title":"Experimental investigation on the anti-detonation performance of composite structure containing foam geopolymer backfill material","authors":"Hang Zhou, Hujun Li, Zhen Wang, Dongming Yan, Wenxin Wang, Guokai Zhang, Zirui Cheng, Song Sun, Mingyang Wang","doi":"10.1016/j.dt.2024.08.011","DOIUrl":"https://doi.org/10.1016/j.dt.2024.08.011","url":null,"abstract":"The compression and energy absorption properties of foam geopolymers increase stress wave attenuation under explosion impacts, reducing the vibration effect on the structure. Explosion tests were conducted using several composite structure models, including a concrete lining structure (CLS) without foam geopolymer and six foam geopolymer composite structures (FGCS) with different backfill parameters, to study the dynamic response and wave dissipation mechanisms of FGCS under explosive loading. Pressure, strain, and vibration responses at different locations were synchronously tested. The damage modes and dynamic responses of different models were compared, and how wave elimination and energy absorption efficiencies were affected by foam geopolymer backfill parameters was analyzed. The results showed that the foam geopolymer absorbed and dissipated the impact energy through continuous compressive deformation under high strain rates and dynamic loading, reducing the strain in the liner structure by 52% and increasing the pressure attenuation rate by 28%. Additionally, the foam geopolymer backfill reduced structural vibration and liner deformation, with the FGCS structure showing 35% less displacement and 70% less acceleration compared to the CLS. The FGCS model with thicker, less dense foam geopolymer backfill, having more pores and higher porosity, demonstrated better compression and energy absorption under dynamic impact, increasing stress wave attenuation efficiency. By analyzing the stress wave propagation and the compression characteristics of the porous medium, it was concluded that the stress transfer ratio of FGCS-ρ-579 was 77% lower than that of CLS, and the transmitted wave energy was 90% lower. The results of this study provide a scientific basis for optimizing underground composite structure interlayer parameters.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"9 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188941","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

Damage analysis caused by 60Co ions in functionally graded materials 60Co 离子在功能分级材料中造成的损伤分析

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-19 DOI: 10.1016/j.dt.2024.08.012

Zübeyde Özkan, Uğur Gökmen, Sema Bilge Ocak

引用次数: 0

A novel detection method for warhead fragment targets in optical images under dynamic strong interference environments 动态强干扰环境下光学图像中弹头碎片目标的新型检测方法

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-15 DOI: 10.1016/j.dt.2024.08.008

Guoyi Zhang, Hongxiang Zhang, Zhihua Shen, Deren Kong, Chenhao Ning, Fei Shang, Xiaohu Zhang

{"title":"A novel detection method for warhead fragment targets in optical images under dynamic strong interference environments","authors":"Guoyi Zhang, Hongxiang Zhang, Zhihua Shen, Deren Kong, Chenhao Ning, Fei Shang, Xiaohu Zhang","doi":"10.1016/j.dt.2024.08.008","DOIUrl":"https://doi.org/10.1016/j.dt.2024.08.008","url":null,"abstract":"A measurement system for the scattering characteristics of warhead fragments based on high-speed imaging systems offers advantages such as simple deployment, flexible maneuverability, and high spatiotemporal resolution, enabling the acquisition of full-process data of the fragment scattering process. However, mismatches between camera frame rates and target velocities can lead to long motion blur tails of high-speed fragment targets, resulting in low signal-to-noise ratios and rendering conventional detection algorithms ineffective in dynamic strong interference testing environments. In this study, we propose a detection framework centered on dynamic strong interference disturbance signal separation and suppression. We introduce a mixture Gaussian model constrained under a joint spatial-temporal-transform domain Dirichlet process, combined with total variation regularization to achieve disturbance signal suppression. Experimental results demonstrate that the proposed disturbance suppression method can be integrated with certain conventional motion target detection tasks, enabling adaptation to real-world data to a certain extent. Moreover, we provide a specific implementation of this process, which achieves a detection rate close to 100% with an approximate 0% false alarm rate in multiple sets of real target field test data. This research effectively advances the development of the field of damage parameter testing.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"10 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259501","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 status of high efficiency deep penetration welding of medium-thick plate titanium alloy: A review 中厚板钛合金高效深熔透焊接的研究现状：综述

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-14 DOI: 10.1016/j.dt.2024.08.004

Zhihai Dong, Ye Tian, Long Zhang, Tong Jiang, Dafeng Wang, Yunlong Chang, Donggao Chen

引用次数: 0

Resilient multi-objective mission planning for UAV formation: A unified framework integrating task pre- and re-assignment 无人机编队的弹性多目标任务规划：整合任务预分配和重新分配的统一框架

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-13 DOI: 10.1016/j.dt.2024.08.002

Xinwei Wang, Xiaohua Gao, Lei Wang, Xichao Su, Junhong Jin, Xuanbo Liu, Zhilong Deng

{"title":"Resilient multi-objective mission planning for UAV formation: A unified framework integrating task pre- and re-assignment","authors":"Xinwei Wang, Xiaohua Gao, Lei Wang, Xichao Su, Junhong Jin, Xuanbo Liu, Zhilong Deng","doi":"10.1016/j.dt.2024.08.002","DOIUrl":"https://doi.org/10.1016/j.dt.2024.08.002","url":null,"abstract":"Combat effectiveness of unmanned aerial vehicle (UAV) formations can be severely affected by the mission execution reliability. During the practical execution phase, there are inevitable risks where UAVs being destroyed or targets failed to be executed. To improve the mission reliability, a resilient mission planning framework integrates task pre- and re-assignment modules is developed in this paper. In the task pre-assignment phase, to guarantee the mission reliability, probability constraints regarding the minimum mission success rate are imposed to establish a multi-objective optimization model. And an improved genetic algorithm with the multi-population mechanism and specifically designed evolutionary operators is used for efficient solution. As in the task-reassignment phase, possible trigger events are first analyzed. A real-time contract net protocol-based algorithm is then proposed to address the corresponding emergency scenario. And the dual objective used in the former phase is adapted into a single objective to keep a consistent combat intention. Three cases of different scales demonstrate that the two modules cooperate well with each other. On the one hand, the pre-assignment module can generate high-reliability mission schedules as an elaborate mathematical model is introduced. On the other hand, the re-assignment module can efficiently respond to various emergencies and adjust the original schedule within a millisecond. The corresponding animation is accessible at bilibili.com/video/BV12t421w7EE for better illustration.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"23 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189176","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

Optimization of mechanical and safety properties by designing interface characteristics within energetic composites 通过设计高能复合材料的界面特性优化机械和安全性能

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-10 DOI: 10.1016/j.dt.2024.08.007

Guijun Wang, Yanqing Wu, Kun Yang, Quanzhi Xia, Fenglei Huang

{"title":"Optimization of mechanical and safety properties by designing interface characteristics within energetic composites","authors":"Guijun Wang, Yanqing Wu, Kun Yang, Quanzhi Xia, Fenglei Huang","doi":"10.1016/j.dt.2024.08.007","DOIUrl":"https://doi.org/10.1016/j.dt.2024.08.007","url":null,"abstract":"The interfacial structure has an important effect on the mechanical properties and safety of the energetic material. In this work, a mesostructure model reflecting the real internal structure of PBX is established through image digital modeling and vectorization processing technology. The microscopic molecular structure model of PBX is constructed by molecular dynamics, and the interface bonding energy is calculated and transferred to the mesostructure model. Numerical simulations are used to study the influence of the interface roughness on the dynamic compression and impact ignition response of PBX, and to regulate and optimize the mechanical properties and safety of the explosive to obtain the optimal design of the surface roughness of the explosive crystal. The results show that the critical hot spot density of PBX ignition under impact loading is 0.68 mm. The improvement of crystal surface roughness can improve the mechanical properties of materials, but at the same time it can improve the impact ignition sensitivity and reduce the safety of materials. The optimal friction coefficient range for the crystal surface that satisfies both the mechanical properties and safety of PBX is 0.06–0.12. This work can provide a reference basis for the formulation design and production processing of energetic materials.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"38 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189180","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

Preparation and microwave absorption performance of SiC aerogel via sol-gel and carbonization reduction process 通过溶胶-凝胶和碳化还原工艺制备碳化硅气凝胶及其微波吸收性能

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-10 DOI: 10.1016/j.dt.2024.08.006

Xinli Ye, Pengyi Xu, Hao Yu, Shan Li, Xiaomin Ma, Wei Xu, Junxiong Zhang

引用次数: 0

Critical quality indicators of high-performance polyetherimide (ULTEM) over the MEX 3D printing key generic control parameters: Prospects for personalized equipment in the defense industry 高性能聚醚酰亚胺（ULTEM）对 MEX 3D 打印关键通用控制参数的关键质量指标：国防工业个性化设备的发展前景

IF 5.1 2区工程技术

Defence Technology Pub Date : 2024-08-02 DOI: 10.1016/j.dt.2024.08.001

Nectarios Vidakis, Markos Petousis, Constantine David, Nektarios K. Nasikas, Dimitrios Sagris, Nikolaos Mountakis, Mariza Spiridaki, Amalia Moutsopoulou, Emmanuel Stratakis

{"title":"Critical quality indicators of high-performance polyetherimide (ULTEM) over the MEX 3D printing key generic control parameters: Prospects for personalized equipment in the defense industry","authors":"Nectarios Vidakis, Markos Petousis, Constantine David, Nektarios K. Nasikas, Dimitrios Sagris, Nikolaos Mountakis, Mariza Spiridaki, Amalia Moutsopoulou, Emmanuel Stratakis","doi":"10.1016/j.dt.2024.08.001","DOIUrl":"https://doi.org/10.1016/j.dt.2024.08.001","url":null,"abstract":"Additive Manufacturing (AM) can provide customized parts that conventional techniques fail to deliver. One important parameter in AM is the quality of the parts, as a result of the material extrusion 3D printing (3D-P) procedure. This can be very important in defense-related applications, where optimum performance needs to be guaranteed. The quality of the Polyetherimide 3D-P specimens was examined by considering six control parameters, namely, infill percentage, layer height, deposition angle, travel speed, nozzle, and bed temperature. The quality indicators were the root mean square (q) and average (a) roughness, porosity, and the actual to nominal dimensional deviation. The examination was performed with optical profilometry, optical microscopy, and micro-computed tomography scanning. The Taguchi design of experiments was applied, with twenty-five runs, five levels for each control parameter, on five replicas. Two additional confirmation runs were conducted, to ensure reliability. Prediction equations were constructed to express the quality indicators in terms of the control parameters. Three modeling approaches were applied to the experimental data, to compare their efficiency, i.e., Linear Regression Model (LRM), Reduced Quadratic Regression Model, and Quadratic Regression Model (QRM). QRM was the most accurate one, still the differences were not high even considering the simpler LRM model.","PeriodicalId":10986,"journal":{"name":"Defence Technology","volume":"19 1","pages":""},"PeriodicalIF":5.1,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189179","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