Defence Technology(防务技术)最新文献

{"title":"Effects of aging on mechanical sensitivity threshold and thermal decomposition characteristic of RDX/HMX","authors":"Shian Zhang ,&nbsp;Yanru Wang ,&nbsp;Zeshan Wang ,&nbsp;Deyun Liu ,&nbsp;Mingkun Fang ,&nbsp;Zhiyong Ma ,&nbsp;Xingliang Wu ,&nbsp;Xibo Jiang ,&nbsp;Sen Xu ,&nbsp;Dabin Liu","doi":"10.1016/j.dt.2024.10.011","DOIUrl":"10.1016/j.dt.2024.10.011","url":null,"abstract":"<div><div>In order to analyze the influences of storage aging on the safety of typical elemental explosives, the aged cyclotrimethylene trinitramine (RDX) and cyclotetramethylene tetranitramine (HMX) were prepared by isothermal aging tests. The reaction thresholds of aged RDX and HMX under any ignition probability were studied by Langlie-Optimal D method. The thermal decomposition characteristics of RDX and HMX after aging were analyzed by DSC and ARC. Experimental results showed that compared with unaged RDX and HMX, on the one hand, the critical impact energy and critical friction of RDX and HMX aged for 14, 28, and 56 days are significantly reduced at an explosion probability of 50%, 0.01%, and 0.0001%, respectively. With the increase of aging time, the mechanical sensitivity of RDX and HMX increases obviously. On the other hand, the initial decomposition temperature of RDX and HMX after 56 days of aging decreases, the decomposition heat decreases, the activation energy increases, and the reaction difficulty increases.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 62-72"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620433","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}

{"title":"The superior ballistic performance of highly stretchable and flexible double-face knitted fabrics (DFKF): An experimental investigation","authors":"Yi Zhou ,&nbsp;Xiangpeng Xin ,&nbsp;Yang Li ,&nbsp;Yang Zhou ,&nbsp;Rui Zhang ,&nbsp;Lizhi Xu","doi":"10.1016/j.dt.2024.10.005","DOIUrl":"10.1016/j.dt.2024.10.005","url":null,"abstract":"<div><div>When the protective and protected systems are detached, the former can be allowed to absorb the kinetic energy of the impacting projectile through large deformation without considering the back face signature of the latter. This paper presents a novel double-face knitted fabric (DFKF) designed for this very impacting scenario. Shooting tests equipped with high-speed camera were used to characterize the ballistic performance with the impact velocities ranging from 100 m/s to 450 m/s. The results showed that the ballistic limits (<em>V</em>_bl) of DFKF are approximately triple and double that of its counterpart UD and plain fabrics, respectively. For mass-normalized metrics, the specific energy absorption (SEA) is 250% and 350% greater than the UD and plain fabrics at their corresponding <em>V</em>_bls. The quasi-static tests showed that the DFKF displayed greater resilience, crease recovery properties, and flexibility, which also made it an especially better candidate than UD and plain weaves for the design of umbrella surface cloth. It was also found that DFKF is dependent on yarn count and the incorporation of spandex. A prototype anti-ballistic umbrella is manufactured using DFKF made of 200D multi-filament yarn. The ballistic performance is also sensitive to the impact site when the umbrella is subjected to impact.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 119-136"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620441","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}

{"title":"Development of a composite sandwich-structure piezoresistive pressure sensor for subtle-pressures application","authors":"Mosayeb Shiri,&nbsp;Nowrouz Mohammad Nouri,&nbsp;Mohammad Riahi","doi":"10.1016/j.dt.2024.06.011","DOIUrl":"10.1016/j.dt.2024.06.011","url":null,"abstract":"<div><div>The Design and manufacturing of a noble piezoresistive pressure sensor (PS) for subtle pressures (&lt;1 kPa) were presented. Meanwhile, in the studies conducted in the field of pressure sensors, the measurement of subtle pressures has received less attention. The limitations in the inherent gauge factor in silicon, have led to the development of polymer and composite resistive sensitive elements. However, in the development of resistance sensing elements, the structure of composite elements with reinforcement core has not been used. The proposed PS had a composite sandwich structure consisting of a nanocomposite graphene layer covered by layers of PDMS at the bottom and on the top coupled with a polyimide (PI) core. Various tests were performed to analyze the PS. The primary design target was improved sensitivity, with a finite-element method (FEM) utilized to simulate the stress profile over piezoresistive elements and membrane deflection at various pressures. The PS manufacturing process is based on Laser-engraved graphene (LEG) technology and PDMS casting. Experimental data indicated that the manufactured PS exhibits a sensitivity of 67.28 mV/kPa for a pressure range of 30–300 Pa in ambient temperature.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 48-61"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620436","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}

{"title":"Iterated rational quadratic kernel - High-order unscented Kalman filtering algorithm for spacecraft tracking","authors":"Xinru Liang,&nbsp;Changsheng Gao,&nbsp;Wuxing Jing,&nbsp;Ruoming An","doi":"10.1016/j.dt.2024.08.021","DOIUrl":"10.1016/j.dt.2024.08.021","url":null,"abstract":"<div><div>The high-speed development of space defense technology demands a high state estimation capacity for spacecraft tracking methods. However, reentry flight is accompanied by complex flight environments, which brings to the uncertain, complex, and strongly coupled non-Gaussian detection noise. As a result, there are several intractable considerations on the problem of state estimation tasks corrupted by complex non-Gaussian outliers for non-linear dynamics systems in practical application. To address these issues, a new iterated rational quadratic (RQ) kernel high-order unscented Kalman filtering (IRQ-HUKF) algorithm via capturing the statistics to break through the limitations of the Gaussian assumption is proposed. Firstly, the characteristic analysis of the RQ kernel is investigated in detail, which is the first attempt to carry out an exploration of the heavy-tailed characteristic and the ability on capturing high-order moments of the RQ kernel. Subsequently, the RQ kernel method is first introduced into the UKF algorithm as an error optimization criterion, termed the iterated RQ kernel-UKF (RQ-UKF) algorithm by derived analytically, which not only retains the high-order moments propagation process but also enhances the approximation capacity in the non-Gaussian noise problem for its ability in capturing high-order moments and heavy-tailed characteristics. Meanwhile, to tackle the limitations of the Gaussian distribution assumption in the linearization process of the non-linear systems, the high-order Sigma Points (SP) as a subsidiary role in propagating the state high-order statistics is devised by the moments matching method to improve the RQ-UKF. Finally, to further improve the flexibility of the IRQ-HUKF algorithm in practical application, an adaptive kernel parameter is derived analytically grounded in the Kullback-Leibler divergence (KLD) method and parametric sensitivity analysis of the RQ kernel. The simulation results demonstrate that the novel IRQ-HUKF algorithm is more robust and outperforms the existing advanced UKF with respect to the kernel method in reentry vehicle tracking scenarios under various noise environments.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 238-250"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620263","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}

{"title":"An improved efficient adaptive method for large-scale multi-explosives explosion simulations","authors":"Tao Li ,&nbsp;Cheng Wang ,&nbsp;Baojun Shi","doi":"10.1016/j.dt.2024.10.012","DOIUrl":"10.1016/j.dt.2024.10.012","url":null,"abstract":"<div><div>Shock wave caused by a sudden release of high-energy, such as explosion and blast, usually affects a significant range of areas. The utilization of a uniform fine mesh to capture sharp shock wave and to obtain precise results is inefficient in terms of computational resource. This is particularly evident when large-scale fluid field simulations are conducted with significant differences in computational domain size. In this work, a variable-domain-size adaptive mesh enlargement (vAME) method is developed based on the proposed adaptive mesh enlargement (AME) method for modeling multi-explosives explosion problems. The vAME method reduces the division of numerous empty areas or unnecessary computational domains by adaptively suspending enlargement operation in one or two directions, rather than in all directions as in AME method. A series of numerical tests via AME and vAME with varying nonintegral enlargement ratios and different mesh numbers are simulated to verify the efficiency and order of accuracy. An estimate of speedup ratio is analyzed for further efficiency comparison. Several large-scale near-ground explosion experiments with single/multiple explosives are performed to analyze the shock wave superposition formed by the incident wave, reflected wave, and Mach wave. Additionally, the vAME method is employed to validate the accuracy, as well as to investigate the performance of the fluid field and shock wave propagation, considering explosive quantities ranging from 1 to 5 while maintaining a constant total mass. The results show a satisfactory correlation between the overpressure versus time curves for experiments and numerical simulations. The vAME method yields a competitive efficiency, increasing the computational speed to 3.0 and approximately 120,000 times in comparison to AME and the fully fine mesh method, respectively. It indicates that the vAME method reduces the computational cost with minimal impact on the results for such large-scale high-energy release problems with significant differences in computational domain size.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 28-47"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620435","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}

{"title":"TDNN: A novel transfer discriminant neural network for gear fault diagnosis of ammunition loading system manipulator","authors":"Ming Li,&nbsp;Longmiao Chen,&nbsp;Manyi Wang,&nbsp;Liuxuan Wei,&nbsp;Yilin Jiang,&nbsp;Tianming Chen","doi":"10.1016/j.dt.2024.08.014","DOIUrl":"10.1016/j.dt.2024.08.014","url":null,"abstract":"<div><div>The ammunition loading system manipulator is susceptible to gear failure due to high-frequency, heavy-load reciprocating motions and the absence of protective gear components. After a fault occurs, the distribution of fault characteristics under different loads is markedly inconsistent, and data is hard to label, which makes it difficult for the traditional diagnosis method based on single-condition training to generalize to different conditions. To address these issues, the paper proposes a novel transfer discriminant neural network (TDNN) for gear fault diagnosis. Specifically, an optimized joint distribution adaptive mechanism (OJDA) is designed to solve the distribution alignment problem between two domains. To improve the classification effect within the domain and the feature recognition capability for a few labeled data, metric learning is introduced to distinguish features from different fault categories. In addition, TDNN adopts a new pseudo-label training strategy to achieve label replacement by comparing the maximum probability of the pseudo-label with the test result. The proposed TDNN is verified in the experimental data set of the artillery manipulator device, and the diagnosis can achieve 99.5%, significantly outperforming other traditional adaptation methods.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 84-98"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620438","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}

{"title":"Review of bumper materials for spacecraft shield against orbital debris hypervelocity impact","authors":"Siyuan Ren ,&nbsp;Pinliang Zhang ,&nbsp;Qiang Wu ,&nbsp;Qingming Zhang ,&nbsp;Zizheng Gong ,&nbsp;Guangming Song ,&nbsp;Renrong Long ,&nbsp;Liangfei Gong ,&nbsp;Mingze Wu","doi":"10.1016/j.dt.2024.09.002","DOIUrl":"10.1016/j.dt.2024.09.002","url":null,"abstract":"<div><div>It is widely known that the hypervelocity impact of orbital debris can cause serious damage to spacecraft, and enhancing the impact resistance is the great concern of spacecraft shield design. This paper provides a comprehensive overview of advances in the development of bumper materials for spacecraft shield applications. In particular, the protective mechanism and process of the bumper using different materials against hypervelocity impact are reviewed and discussed. The advantages and disadvantages of each material used in shield were discussed, and the performance under hypervelocity impact was given according to the specific configuration. This review provides the useful reference and basis for researchers and engineers to create bumper materials for spacecraft shield applications, and the contemporary challenges and future directions for bumper materials for spacecraft shield were presented.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 137-177"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620442","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}

{"title":"LPI radar sequence design against cyclostationary analysis","authors":"Qiang Liu,&nbsp;Fucheng Guo,&nbsp;Kunlai Xiong,&nbsp;Xi Li,&nbsp;Guizhou Wu,&nbsp;Weidong Hu","doi":"10.1016/j.dt.2024.08.020","DOIUrl":"10.1016/j.dt.2024.08.020","url":null,"abstract":"<div><div>In this paper, we present a novel unimodular sequence design algorithm based on the coordinate descent (CD) algorithm, aimed at countering electronic surveillance (ES) systems based on cyclostationary analysis. Our algorithm not only provides resistance against cyclostationary analysis (CSA) but also maintains low integrated sidelobe (ISL) characteristics. Initially, we derive the expression of the cyclostationary feature (CSF) detector and simplify it into an iterative quadratic form. Additionally, we derive a quadratic form to ensure the similarity of the autocorrelation sidelobes. To balance the minimization of the detection probability and the ISL values, we introduce a Pareto scalar that transforms the multi-objective optimization problem into a convex combination of objective functions. This approach allows us to find an optimal trade-off between the two objectives. Finally, we propose a monotonic algorithm based on the CD algorithm to counter CSA analysis. This algorithm efficiently solves the optimization problem mentioned earlier. Numerical experiments are conducted to validate the correctness and effectiveness of our proposed algorithm.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 227-237"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620262","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}

{"title":"Anti-migration of NG by using EPDM insulation materials coated with reduced graphene oxide","authors":"Liyun Lin ,&nbsp;Lipeng Sang ,&nbsp;Yiheng Li ,&nbsp;Jiawei Yan ,&nbsp;Panpan Peng ,&nbsp;Qilong Yan ,&nbsp;Bowen Tao ,&nbsp;Xiang Guo","doi":"10.1016/j.dt.2024.10.004","DOIUrl":"10.1016/j.dt.2024.10.004","url":null,"abstract":"<div><div>The migration of nitroglycerin (NG) has always been the critical issue that harmfully impacts the structural integrity and operational reliability of the solid rocket motor, which is mainly composed by Nitrate Ester Plasticized Polyether (NEPE) propellant/Hydroxyl-terminated Polybutadiene (HTPB) liner/Ethylene Propylene Diene Monomer (EPDM) insulation bonding system. This paper proposes an innovative surface modification method attempting to modify the EPDM insulation layer coated with reduced graphene oxide (RGO), which exhibits ability to weaken the NG absorption by EPDM insulation layer, blocking the pathway of NG migration into EPDM insulation materials. The microstructure of RGO-coated layer was analyzed and the formation mechanism was investigated. The RGO-coated layer is well bonded to the HTPB liner, and its anti-migration performance to NG at different temperatures has been evaluated. Comparing with blank samples under the same storage conditions, the RGO-coated layers can reduce the diffusion coefficient of NG by up to 87.3% and increase the diffusion activation energy of NG by 14.8 kJ⋅mol⁻¹. This research provides a new strategy to effectively inhibit NG migration in NEPE propellant/HTPB liner/EPDM insulation bonding system.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 109-118"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620440","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}

{"title":"Reactivity of polyaniline composites with attractive cyclic nitramines","authors":"Veerabhadragouda B. Patil ,&nbsp;Roman Svoboda ,&nbsp;Svatopluk Zeman","doi":"10.1016/j.dt.2024.10.009","DOIUrl":"10.1016/j.dt.2024.10.009","url":null,"abstract":"<div><div>Composite microcrystals of the nitramines (NAs) viz., RDX, HMX, BCHMX, and CL-20 with electrically conductive polyaniline (PANi) are a charge transfer complexes in coagglomerated composite crystals (CACs). The activation energies of thermolysis, <em>E</em>_a, of the pure NAs and their PANi-CACs were determined using the Kissinger method, and decomposition processes are discussed. Except for the RDX/PANi CACs, all the other CACs show higher <em>E</em>_a values for decomposition compared to their pure NA counterparts. For all CACs, relationships are specified between the <em>E</em>_a values, on the one hand, and the squares of the detonation velocities, enthalpies of formation, spark energy and impact sensitivities, on the other. The relationships between their low-temperature heats of decomposition, Δ<em>H</em>, from DSC, and their enthalpy of formation, logarithm of impact sensitivity, electric spark energy, as well as detonation energy, are described. The PANi favorably influences the density of the corresponding CACs; surprisingly close linear correlations were found, and explained, between these densities and the <em>E</em>_a values. This presence of PANi strongly increased the electrical spark sensitivity of the CACs in comparison to the base NAs. Based on the results obtained, it can be noted in particular the exceptional desensitization of HMX to impact and the increased sensitivity to electrical spark by coating its crystals with polyaniline.</div></div>","PeriodicalId":58209,"journal":{"name":"Defence Technology(防务技术)","volume":"45 ","pages":"Pages 1-12"},"PeriodicalIF":5.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620432","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}