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    Research and Development of High-Performance Magnesium Alloys for Aerospace Applications
    SU Yang, HAO Liang, LI Yangxin, ZENG Xiaoqin
    Air & Space Defense    2024, 7 (6): 1-11.  
    Abstract2765)      PDF(pc) (2081KB)(1064)       Save
    Magnesium alloys, currently recognized as the lightest structural metallic material in practical engineering applications, have broad prospects for application in the aerospace field, where lightweight demands are increasing. However, the three major bottleneck issues, “relatively low absolute strength”, “ weak deformation capacity”, and “insufficient corrosion resistance”, greatly limit the application scope of traditional magnesium alloys. Based on a review of the latest application status of magnesium alloys in the aerospace field, this paper has elaborated on the research progress of high-strength, tough, and corrosion-resistant magnesium alloys and prospected the development trends of high-performance magnesium alloys in future aerospace applications.
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    Optimization of Geometrical Parameters of Coandă-Effect-Based Polymetallic Nodule Collection Device
    ZHANG Baiyuan, ZHAO Guocheng, XIAO Longfei
    Journal of Shanghai Jiao Tong University    2025, 59 (8): 1059-1066.   DOI: 10.16183/j.cnki.jsjtu.2023.470
    Abstract2495)   HTML22)    PDF(pc) (3985KB)(594)       Save

    The collection of seabed ore particles is a core technology of exploiting deep sea mineral resources, with wall-attached jet collection technology based on Coandă-effect being considered as a nodule collection method with engineering application potential. Based on the experimentally verified CFD-DEM numerical simulation, the optimization of geometric parameters of the collection device is conducted to improve pick-up efficiency. The influences of three geometric parameters, i.e., the ratio of the curvature radius of the convex curved wall to the diameter of the nodule particle R/d, the tangential radian of the jet θ, and the ratio of the thickness of the jet to the diameter of the nodule b/d on the critical unconditional jet flow rate q0, are investigated and compared. The nodule collection characteristics are revealed through an analysis of the flow field characteristics. The results show that b/d has the greatest influence on the pick-up efficiency, followed by R/d, while θ has the least. The performance of nodule collection is optimal when R/d=9, θ=1.05 rad, and b/d=0.26 in contrast conditions. This research provides technical support for designing and developing the Coandă-effect-based collection devices.

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    Structural Simulation Model Updating Based on Improved MCMC Algorithm and Surrogate Model
    MIAO Ji, DUAN Liping, LIU Jiming, LIN Siwei, ZHAO Jincheng
    Journal of Shanghai Jiao Tong University    2025, 59 (8): 1114-1122.   DOI: 10.16183/j.cnki.jsjtu.2023.584
    Abstract2332)   HTML7)    PDF(pc) (9290KB)(388)       Save

    To enhance the accuracy of finite element model simulation, a model updating method based on Bayesian theory is proposed, and the updating efficiency is improved by integrating improved Markov chain Monte Carlo (MCMC) algorithm and surrogate model. A radial basis function (RBF) surrogate model is constructed using the parameters to be updated as inputs and the finite element model modal responses as outputs. Whale optimization algorithm (WOA) is introduced into the MCMC algorithm and the uncertain parameters are updated. Finally, a numerical study on a simply supported beam and an experimental study on a three-story steel frame are conducted to verify the accuracy of the proposed method. The results show that WOA can significantly improve the stability and convergence speed of the MCMC algorithm, the updating efficiency can be improved by 13.9% at most, and the maximum frequency errors of the simply supported beam model and the three-story steel frame model updated by the WO-MH algorithm are 0.009% and 2.41%, respectively. The proposed model updating method can effectively enhance the simulation accuracy of the finite element model under both two-dimensional and eight-dimensional inputs, which provides technical reference for lean simulation and optimal design of building structures.

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    Parameter Control of Adaptive Bistable Point Absorber Wave Energy Converter in Irregular Waves
    LI Yang, ZHANG Xiantao, XIAO Longfei
    Journal of Shanghai Jiao Tong University    2025, 59 (3): 293-302.   DOI: 10.16183/j.cnki.jsjtu.2023.309
    Abstract2325)   HTML22)    PDF(pc) (4987KB)(466)       Save

    Although the adaptive bistable wave energy generation device solves the problem that the bistable system may be difficult to cross the barrier when the amplitude of the incident wave is small, its efficiency can still be improved. Previous studies have proved that the change of the parameters of the device will have a great impact on its performance, and the optimal device parameters are closely related to the spectral peak frequency at a given time. Therefore, in the control study of the device, a control scheme is designed and the device parameters are adjusted accordingly in order to improve efficiency assuming that the peak frequency within a period of time is predictable. In this study, three control parameters are selected, and the optimal device parameter library with different spectral peak frequencies is determined by simulation calculation. The control module is then added to the simulation program to control the parameters by interpolation. The results show that the device with variable parameter control improves energy capture efficiency.

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    Experimental Study on Vortex-Induced Vibration Force Characteristics of Side-by-Side Double Free-Hanging Water Transmission Pipes Under Uniform Flow
    ZHAO Guangyi, ZHANG Mengmeng, FU Shixiao, XU Yuwang, REN Haojie, BAI Yingli
    Journal of Shanghai Jiao Tong University    2025, 59 (8): 1067-1080.   DOI: 10.16183/j.cnki.jsjtu.2023.539
    Abstract2240)   HTML6)    PDF(pc) (32003KB)(538)       Save

    This paper investigates vortex-induced vibration (VIV) characteristics of double free-hanging water transmission pipes, which are crucial for temperature difference energy harvesting platforms. Compared to a single pipe, double pipes could offer higher transport efficiency and cost-effectiveness. In this paper, model experiments were conducted to analyze VIV characteristics of the double free-hanging pipes and a method for identifying vortex-induced loads for large displacements and small deformations was proposed. A comparative analysis of the VIV characteristics of double free-hanging pipe and the single pipe was performed. The findings show that VIV displacement amplitudes of double free-hanging pipe are similar at low flow velocities but differ with those of single pipe at high velocities. The double free-hanging pipe is more prone to instability in VIV, including traveling waves and multi-frequency responses. The VIV frequencies of double free-hanging pipe can be predicted by the same Strouhal number as that of the single pipe. Additionally, a significant difference in the added mass coefficient affects natural wet frequency adjustment for VIV resonance.

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    A Short-Term Carbon Emission Accounting Method for Power Industry Using Electricity Data Based on a Combined Model of CNN and LightGBM
    ZENG Jincan, HE Gengsheng, LI Yaowang, DU Ershun, ZHANG Ning, ZHU Haojun
    Journal of Shanghai Jiao Tong University    2025, 59 (6): 746-757.   DOI: 10.16183/j.cnki.jsjtu.2023.382
    Abstract2234)   HTML9)    PDF(pc) (6089KB)(3278)       Save

    The electric power industry plays a pivotal role in carbon emission control. Accurate and real-time accounting of carbon emissions in the power industry is essential for supporting the carbon reduction of the power industry. At present, the measurement of carbon emissions in the power industry relies mainly on direct measurement or the accounting methods, which often struggles to balance low measurement costs with real-time accuracy. Therefore, in this paper, the robust power data infrastructure in the power industry is leveraged and the correlation between electricity consumption and carbon emissions is explored to propose a short-term electricity-to-carbon method using machine learning methods based on historical data of electricity. This method utilizes convolutional neural networks (CNNs) for feature extraction, and light gradient boosting machine (LightGBM) for carbon emission estimation based on extracted features. Moreover, K-fold cross-validation is used in model training, with parameter optimization using grid search to enhance the generalization capability and robustness of the model. To validate the proposed method, it is compared with other machine learning models under the same data segmentation condition for daily and hourly data sets. The results indicate that the proposed model outperforms other models in both performance evaluation and the consistency between estimated and target values.

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    An Optimization Method for Iteration Path Search of Large-Scale Power Grid Unit Commitment State
    CUI Yiyang, PAN Dounan, LI Canbing, LIU Jianzhe
    Journal of Shanghai Jiao Tong University    2025, 59 (6): 711-719.   DOI: 10.16183/j.cnki.jsjtu.2024.301
    Abstract2221)   HTML22)    PDF(pc) (1544KB)(155)       Save

    To address the computational challenge posed by the “curse of dimensionality” inherent in traditional branch and bound algorithms for large-scale power grid unit commitment problems, an optimization method for iteration path search of unit commitment state is proposed. To prevent the loss of the optimal solution due to the simplification of the problem and the reduction of the feasible region, the determination of the unit state scheme is divided into a two-stage process of depth traverse and breadth iteration. Based on an initial solution, the unit dynamic priority list is used as the search direction for the unit state iteration path. In deep traverse stage, the optimal shutdown redundant units and their corresponding shutdown time are determined. Breadth iteration is then used to expand the feasible region of the problem to improve the optimality of the solution. The results of a comparative case study conducted on the IEEE 118 system and ACTIVSg10k system indicate that the proposed method effectively reduces the scale of the problem, minimizes the number of unit state attempts, and achieves efficient search and iteration of unit states, exhibiting fast computational speed, high efficiency, which has practical applicability for solving problems of large-scale unit commitment.

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    Research on Construction Method of Digital-Intelligent Parallel Battlefield for Air Defense and Anti-Missile Based on Digital Twin
    WANG Gang, YANG Ke, QUAN Wen, GUO Xiangke, ZHAO Xiaoru
    Air & Space Defense    2025, 8 (3): 1-13.  
    Abstract2214)      PDF(pc) (1209KB)(555)       Save
    The establishment of a digital parallel battlefield that integrates the functions of "research, combat, testing, practical operation, and training" serves as an effective and essential supporting measure for enhancing combat command and joint training capabilities, which address future intelligent high-end warfare among major powers. In the air defense and anti-missile realm, constructing a digital parallel battlefield faces several formidable challenges, including configuring complex scenarios, facilitating interactions between virtual and real forces, and simulating combat behaviours. To tackle these issues, the paper employed a digital twin modelling approach grounded in Model-Based Systems Engineering (MBSE) to enable the precise configuration of complex scenarios. Based on the Live-Virtual-Constructive (LVC) concept, a distributed simulation architecture combining virtual and real elements was established to realise seamless virtual-real interactions and efficient coordination. In addition, an Agent modelling methodology based on data/rules dual-driven was introduced to simulate intelligent combat behaviours in air defense and anti-missile operations. A multi-branch simulation deduction and auxiliary decision-making framework tailored for the parallel battlefield was constructed, achieving the organic integration of situation analysis, plan formulation, and evaluation for optimal selection. The system development was accomplished by applying the software-defined method, enabling dynamic scheduling of system resources, flexible reconfiguration, and agile deployment. The research results indicate that the newly developed digital-intelligent parallel battlefield for air defense and anti-missile, constructed by the concept of the digital twin, provides robust support for simulation applications across multiple scenarios, including equipment testing, combat experiments, joint training, and command decision-making within the domain of air defense and anti-missile.
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    Energy Interaction and Energy Storage Sharing Optimization Method for Users, Base Stations, and Charging Stations
    HU Long, FANG Baling, FAN Feilong, CHEN Dawei, LI Xinxi, ZENG Run
    Journal of Shanghai Jiao Tong University    2025, 59 (7): 877-888.   DOI: 10.16183/j.cnki.jsjtu.2023.407
    Abstract2186)   HTML14)    PDF(pc) (5843KB)(376)       Save

    The internal energy optimization within a single entity of industrial users, base stations, and charging stations is constrained by local power supply and demand limitations, resulting in low utilization of flexible resources such as energy storage and insufficient energy utilization efficiency. To address these issues, an energy sharing and interactive optimization method is proposed for industrial users, base stations, and charging stations based on the quantification of their complementarity and a game-based pricing incentive mechanism. First, a complementary quantification model is developed based on the analysis of the characteristics of industrial users, base stations, and charging stations, using the standard deviation of net load as a complementary indicator. Then, considering the adjustable capabilities of air conditioning and electric vehicles, as well as the proactive decision-making abilities of industrial users, charging stations, and base stations, a master-slave game-based pricing model is established to incentivize the sharing of energy storage and energy interaction among these entities. Next, incorporating 0-1 integer variables, a solution method utilizes the adaptive differential evolution algorithm combined with the mixed-integer optimization theory. Finally, case studies validate that optimizing the energy storage and energy dispatch of industrial users, base stations, and charging stations in different time periods can effectively leverage their complementarity, enhance the economic benefits of each entity, improve the utilization of idle flexible resources, and enhance the overall energy self-consistency of the system.

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    Structural Dynamic Response of Offshore Horizontal Axis Wind Turbine Subjected to Wake-Induced Action
    ZHU Yiqing, WU Feng, ZHOU Dai, HAN Zhaolong, ZHUO Yang, ZHU Hongbo, ZHANG Kai
    Journal of Shanghai Jiao Tong University    2025, 59 (8): 1081-1091.   DOI: 10.16183/j.cnki.jsjtu.2023.476
    Abstract2185)   HTML7)    PDF(pc) (12106KB)(347)       Save

    The study of the dynamic response of a horizontal axis twin wind turbine in tandem arrangement is crucial for ensuring the structural safety of the wind turbine. Based on the computational fluid dynamics (CFD) method, the characteristics of the wake flow field of the downstream turbine, located in the near wake region of the upstream turbine, are analyzed. The time course curves of the aerodynamic loads on the twin turbines are obtained. Structural dynamics and finite element numerical methods are then used to analyze the wind-driven dynamic effects of the upstream and downstream turbine structures. It is found that the wake velocity deficit in the near wake region is significant, causing a reduction in thrust and torque of the downstream turbine by 54.94% and 91.89% respectively. Additionly, the wake turbulence increases cyclic fluctuation of aerodynamic load on the downstream turbine. While the aerodynamic load volatility has a small effect on the dynamic response of the downstream wind turbine, the overall dynamic response is weaker, and the displacement of the downstream wind turbine tower top in the thrust direction is reduced by 50.79%. The results provide technical references for the analysis of aerodynamic response of wind turbine cluster structures in offshore wind farms.

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    Influence of DC-Bus Voltage on Synchronization Stability of Grid-Following Converters
    SI Wenjia, CHEN Junru, ZHANG Chenglin, LIU Muyang
    Journal of Shanghai Jiao Tong University    2025, 59 (3): 313-322.   DOI: 10.16183/j.cnki.jsjtu.2023.321
    Abstract2169)   HTML9)    PDF(pc) (2943KB)(355)       Save

    With the increasing penetration of new energy sources and the development of new power systems, grid-following converter (GFL) plays a crucial role in maintaining the stability of power systems. However, existing transient stability analyses of GFLs assume that the direct current (DC) side behaves as a constant-voltage source, neglecting the effects of DC-bus voltage control. This paper aims to investigate the transient instability mechanism of GFL considering DC-bus voltage control. First, a transient synchronous stability model considering DC voltage control is established, followed by an analysis of the transient synchronous stability of GFL under DC-bus voltage control. The findings indicate that DC voltage control increases the active current reference value and decreases the equivalent damping of the GFL, which in turn reduces its transient synchronous stability of GFL. By increasing the proportional coefficient or reducing the integral coefficient of DC-bus voltage control, transient synchronous stability can be appropriately improved. Finally, the theoretical analysis is validated through MATLAB/Simulink simulations.

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    Research Progress on High-Temperature Resistant Wave Transparent Silicon Nitride Based Ceramics
    YAO Dongxu, YU Xing, GU Hao, LI Jiahao, LIU Wen, LI Rui
    Air & Space Defense    2024, 7 (6): 46-57.  
    Abstract2133)      PDF(pc) (2858KB)(720)       Save
    Silicon nitride ceramics comprehensively have excellent properties such as high strength, high elastic modulus, high-temperature resistance, thermal shock resistance, and low dielectric constant. They are the major candidate materials for high-temperature wave transmitting radome. Currently, research in silicon nitride-based ceramics and composites is popular. This paper has reviewed the research status of silicon nitride ceramics, SiALON ceramics, silicon oxynitride ceramics, nitrogen oxide ceramics, and their composite materials in the past five years. Through the combination of material design and different molding processes, including 3D printing, chemical vapor infiltration (CVI), and precursor impregnation cracking (PIP), the preparation of high-strength-low dielectric silicon nitride-based ceramic materials was acquired, which enables the selection of materials and design support for wavetransparent components of high-Mach vehicles.
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    Research Progress on Lightweight Resin-Based Thermal Protection Materials
    LI Liang, REN Zhiyi, WANG Peng, LUO Yi, SU Zhe, CAI Hongxiang, TIAN Hao, NIU Bo, LONG Donghui
    Air & Space Defense    2024, 7 (6): 58-75.  
    Abstract2120)      PDF(pc) (5237KB)(850)       Save
    Thermal protection systems are significantly important in modern aerospace engineering. When the new generation of vehicles evolves towards higher Mach flight speeds, there is an increasing demand for thermal protection systems that could combine high-temperature resistance, lightweight construction, and integrated thermal protection and insulation. This paper has reviewed the research progress on lightweight resin-based thermal protection materials domestically and internationally and analyzed their development trends in enhanced oxidation resistance, nanoporous structures, and gradient designs. Besides, this study has introduced the thermal protection and insulation mechanisms as well as the mechanical failure mechanisms of nanoporous resin-based materials, thus providing valuable insights for effective design and fabrication.
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    A Review of Equivalent Model-Based State of Charge Estimation Algorithms of Lithium-Ion Battery
    TANG Diyin, WANG Yufu, ZHENG Wenjian, HUANG Xucong, XING Yalan
    Air & Space Defense    2024, 7 (6): 104-111.  
    Abstract2107)      PDF(pc) (1086KB)(1389)       Save
    Due to their high energy density and long life, Lithium-ion batteries are widely applied in fields such as aerospace and smart driving. Accurate estimation of the state of charge (SOC) of a battery is critical. In recent years, SOC estimation methods based on battery equivalent models have been widely used because oftheir advantages of accurate estimation and easy understanding. This paper has elaborated on the classification of battery equivalent models, SOC estimation algorithms, and factors affecting SOC estimation from three aspects. Firstly, the common types of battery models and their characteristics were analyzed; secondly, the commonly used SOC estimation techniques based on battery models were reviewed; finally, the factors affecting the accuracy of SOC estimation and possible solutions were analyzed. The summary of this paper provides references for future research.
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    Distributed Photovoltaic Power Outlier Detection Based on Quantile Regression Neural Network
    WANG Xiaoqian, ZHOU Yusheng, MAO Yuanjun, LI Bin, ZHOU Wenqing, SU Sheng
    Journal of Shanghai Jiao Tong University    2025, 59 (6): 836-844.   DOI: 10.16183/j.cnki.jsjtu.2023.412
    Abstract2097)   HTML3)    PDF(pc) (3885KB)(156)       Save

    The distributed photovoltaic power generation system is widely dispersed and lacks a scientific and standardized operation and maintenance management system. Due to the limited availability of data, it is difficult to accurately detect abnormal conditions in photovoltaic devices caused by fluctuations in weather. In this paper, according to the operation and maintenance status and data characteristics of distributed photovoltaic, a quantile regression neural network (QRNN)-based method is proposed for detecting photovoltaic power outliers. First, the solar irradiance characteristics of sunny days are analyzed, and the influence of rainy weather is excluded by using a sunny day screening method. Then, the power output correlation of different power stations is analyzed to identify the photovoltaic stations with high power output correlation, which is used as a horizontal reference. Subsequently, the curves of the power output of the stations tested on different sunny days are compared vertically to eliminate the interfering factors such as weather and environmental conditions. The measured active power data is fed into the QRNN model to establish the normal active power range for the photovoltaic system, whose threshold is used to detect photovoltaic power outliers. The simulation results of actual photovoltaic system data show that the method proposed can eliminate the meteorological influence, accurately identify the faulty photovoltaic system, and promote the fine operation and maintenance of distributed photovoltaic.

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    TSM-TLHS Prediction Method for Assembly Deformation of Large Curved Thin Plates in Shipbuilding
    JIN Xuancheng, HONG Ge, GAO Shuo, XIA Tangbin, HU Xiaofeng, XI Lifeng
    Journal of Shanghai Jiao Tong University    2025, 59 (8): 1092-1102.   DOI: 10.16183/j.cnki.jsjtu.2023.576
    Abstract2097)   HTML7)    PDF(pc) (17433KB)(379)       Save

    During the block assembly, large curved thin plates (such as outer plates) undergo deformation due to the force of gravity when they are placed on the jigs, which affects the accuracy and quality of the block assembly in shipbuilding. In order to predict the deformation of these large curved thin plates within a given jig layout, this paper introduces a Transformer-based surrogate model with two-stage Latin hypercube sampling (TSM-TLHS). Primarily, compared to traditional approaches, the two-stage Latin hypercube sampling (TLHS) method enables direct sampling of irregularly shaped thin plates. Simultaneously, this paper uses a Transformer-based surrogate model (TSM) incorporating multi-head attention modules and positional encoding to comprehensively consider the impact of jig positions and corresponding node displacements on thin plate deformation. Real case results demonstrate that the prediction error of this TSM-TLHS method is only 61 μm, meeting the on-site assembly precision requirements for predicting plate deformation. This facilitates timely anti-deformation compensation by block in shipyards, ensuring assembly quality.

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    Research and Development of High-Temperature Titanium Alloys for Hypersonic Aircraft
    CHEN Zhiyong
    Air & Space Defense    2024, 7 (6): 38-45.  
    Abstract2043)      PDF(pc) (1510KB)(1085)       Save
    High-temperature titanium alloys allow broad application prospects in hypersonic aircraft. They have ideal lightweight and heat-resistant metallic materials, enhancing the performance and reliability of hypersonic aircraft in extreme flight environments, thus achieving higher speeds and longer flight distances. Considering the services of thermal structures in China’s hypersonic aircraft, starting from the characteristics of high-temperature titanium alloys, this paper has reviewed the latest development status of high-temperature titanium alloys domestically and abroad. It focused on introducing China’s independent research, development and application of 550-650 °C high-temperature titanium alloys. To achieve higher operating temperature requirements, the research and development of a new 700-750 °C high-temperature titanium alloy Ti750S was proposed, and the respective application directions and prospects of high-temperature titanium alloys for future hypersonic aircraft were prospected.
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    Feature Extraction and Anomaly Identification Method for Power Customer Price in Power Market Enviroment
    ZHU Feng, SHAN Chao, WU Ning, CAI Qixin, ZHU Yunan, LIU Yunpeng, ZUO Qiang
    Journal of Shanghai Jiao Tong University    2025, 59 (7): 995-1006.   DOI: 10.16183/j.cnki.jsjtu.2023.448
    Abstract2037)   HTML6)    PDF(pc) (2218KB)(420)       Save

    Identifying electricity price anomalies and exploring the underlying reasons in such a complex market environment, especially with incomplete data, is a key issue for promoting the orderly operation of power market and ensuring the reasonable interests of power customers. Therefore, a method is established for feature extraction and anomaly identification of electricity prices for power customers. First, an electricity price feature vector is constructed, and its dimensionality is reduced using a spectral clustering algorithm. Then, typical electricity price characteristics are extracted as the basic standard for determining price anomalies. Next, the similarity between each power customer and typical electricity price characteristics is calculated. Finally, electricity price anomalies are identified in two stages. The causes of anomalies are initially and rapidly identified based on electricity consumption and trading behavior, and then further identified in-depth. Case analysis shows that this method can quickly and effectively extract typical electricity price features and identify anomalies. The reasons behind these anomalies are further analyzed from both electricity consumption and trading behaviors, and corresponding improvement measures are proposed.

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    Automatic Filling Optimization Design of Filler Bodies in Umbilical Cross-Section Based on Quasi-Physical Algorithm
    YIN Xu, CAO Donghui, TIAN Geng, YANG Zhixun, FAN Zhirui, WANG Gang, LU Yucheng, WANG Hui
    Journal of Shanghai Jiao Tong University    2025, 59 (8): 1103-1113.   DOI: 10.16183/j.cnki.jsjtu.2023.588
    Abstract2034)   HTML15)    PDF(pc) (11198KB)(286)       Save

    As a key component in the subsea production system for oil and gas exploitation, a marine umbilical consists of optical cables, electrical cables, steel tubes, and filler bodies. The difference of materials and dimensions between the components leads to a great difference in their mechanical properties, and the different layouts cause a large gap in the performance of an umbilical. Considering the compactness, balance, and heat source dispersion of the cross-section, a multi-objective optimization model is established in this paper. Based on the quasi-physical algorithm, the layout design of cross-section of an umbilical containing equal-diameter components is conducted. Due to the mutual constraints between functional components, the optimized cross-section will have large gap. In order to meet the requirement of dense cross-sectional layout in the umbilical cable design specification, a strategy for automatically filling filler bodies based on image recognition is introduced, in combination with the layout optimization process. Finally, taking an umbilical as an example, the filling strategy is utilized to complete the design of cross-sectional filler bodies after obtaining the optimal layout through the quasi-physical algorithm. The algorithm is validated by comparison with the initial cross-sectional layout, demonstrating its effectiveness as a reference for the design of cross-sectional filler bodies of umbilicals.

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    Mode Transition Control of Parallel Gas-Electric Hybrid Power System with Uncertain Delay
    FU Shenglai, CHEN Li, CHEN Ziqiang
    Journal of Shanghai Jiao Tong University    2025, 59 (9): 1225-1236.   DOI: 10.16183/j.cnki.jsjtu.2023.473
    Abstract2025)   HTML11)    PDF(pc) (6267KB)(342)       Save

    Parallel gas-electric hybrid systems have broad application prospects in low-carbon ships due to their few emissions and dynamic performance. However, uncertain delays in multiple actuators during mode transition can cause violent fluctuations in the shaft speed along the power drive. In this paper, a cascaded internal mode control (IMC) consisting of filters with explicit nominal delay is proposed to improve speed tracking performance and eliminate the effect of delay. A dynamic model of the marine driveline is developed, and the cascade IMC is designed based on the driveline mechanism with the clutch serving as the separating component. The cascade IMC consists of an anti-saturation compensator, a two-stage tracking controller, and a two-stage anti-interference controller. Finally, the small-gain theorem is derived to ensure robust stability conditions, taking the upper bound of the uncertain delays into consideration. The results of simulation and dynamometer test show that the cascaded IMC has excellent robustness in handling uncertain delays, significantly reduces shaft jerk, and ensures smooth mode transition.

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    From Kill Chain to Kill Web: A Survey on Modeling, Evaluation, and Optimization
    WANG Chaochen, JIANG Hongru, WANG Buli, XIA Qiaowei, ZHANG Xianchun
    Air & Space Defense    2025, 8 (4): 1-8.  
    Abstract2010)      PDF(pc) (992KB)(377)       Save
    This paper comprehensively and systematically analyzed the theoretical evolution, model construction, effectiveness evaluation, and optimization methodologies of kill chains and webs. First, the fundamental distinctions between kill chains and kill webs were introduced via conceptual comparative analysis. Then, from the perspective of four key modeling challenges: structured information representation, cooperative system optimization, dynamic adaptability, and intelligent decision-making, the construction mechanisms and technological breakthroughs of various models were investigated. Quantitative evaluation methods for key dimensions, including survivability, resilience, and node importance, were summarized. Following this, strategies for dynamic reconstruction optimization and multi-objective conflict resolution were studied. Finally, future development trends of kill chains and kill webs were projected.
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    Physics-Informed Fast Transient Stability Assessment of Non-Fixed Length in Power Systems
    LI Xiang, CHEN Siyuan, ZHANG Jun, KE Deping, GAO Jiemai, YANG Huanhuan
    Journal of Shanghai Jiao Tong University    2025, 59 (7): 962-970.   DOI: 10.16183/j.cnki.jsjtu.2023.452
    Abstract2001)   HTML2)    PDF(pc) (1706KB)(930)       Save

    Against the backdrop of “dual carbon” goals, the construction of a new power system with new energy as the main component is the main direction and key way for the transformation and upgrading of the power industry. Research into fast and accurate evaluation of transient power angle stability in the context of new power systems is of great significance. To address this, a new transient power angle stability evaluation method is proposed for power systems with grid-forming new energy based on the physics-informed sequence-to-sequence (PI-seq2seq) neural networks and cascaded convolutional neural networks models. First, the PI-seq2seq network structure is used to predict the future power angle trajectory, and a loss function with physical loss terms is constructed to guide the model training process, which avoids the long-duration time-domain simulation to ensure fast transient evaluation. Then, predicted power angle trajectory is taken as input by the cascade convolutional neural networks to evaluate the transient stability and its confidence level. A threshold judgment mechanism for the evaluation confidence level is configured to realize the transient stability judgment of the non-fixed evaluation length, which overcomes the impact of the fixed power angle curve length on the evaluation results. Finally, the method proposed is verified in the Kundur system, and the simulation results show that it has obtained satisfactory results in both the power angle curve prediction and the stability evaluation.

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    Optimal Scheduling Strategy of Newly-Built Microgrid in Small Sample Data-Driven Mode
    CHEN Shi, YANG Linsen, LIU Yihong, LUO Huan, ZANG Tianlei, ZHOU Buxiang
    Journal of Shanghai Jiao Tong University    2025, 59 (6): 732-745.   DOI: 10.16183/j.cnki.jsjtu.2023.394
    Abstract1999)   HTML10)    PDF(pc) (4880KB)(388)       Save

    Newly built microgrids lack historical operation data, making it challenging to predict renewable power output accurately using conventional data-driven methods, which in turn affects the accuracy of scheduling plans. To address this problem, an optimal scheduling method for newly built microgrids in scenarios with limited sample data is proposed. First, an improved network structure integrating a domain adversarial neural network with a long-short-term memory network is designed. The domain adversarial approach and gradient inversion mechanism are incorporated into transfer learning to improve the generalization ability of the model. This reduces the domain distribution discrepancy in the data, and uses the rich operation data of power stations with similar output characteristics to predict the output of the target station, which overcomes the challenge of poor accuracy under the conditions of small samples. Additionally, the optimal scheduling model is transformed into a Markov decision process and solved using double-delay deep deterministic policy gradient algorithm. Finally, the effectiveness of the proposed method is validated through a case study involving an improved CIGRE 14-node microgrid.

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    Unit Commitment Optimization Model Considering Impact of Multiple Operating Conditions on Unit Life Loss
    LUO Yifu, HU Qinran, QIAN Tao, CHEN Tao, ZHANG Yuanshi, ZHANG Fei, WANG Qi
    Journal of Shanghai Jiao Tong University    2025, 59 (6): 768-779.   DOI: 10.16183/j.cnki.jsjtu.2023.401
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    Thermal power units face a dilemma of accelerated lifespan degradation and extended service duration. On one hand, large-scale integration of new energy sources has increased peak shaving conditions and accelerated losses of the units. On the other hand, service units will reach designed lifespan before carbon neutrality is achieved, while flexible operation of the power system necessitates extending their service life of units. Therefore, it is of great significance to consider the losses caused by varicus operating conditions on the lifespan of the unit and optimize the operating structure of the unit in scheduling simulation for unit longevity and carbon reduction efforts. To make unit life losses in theoretical research more practical, the traditional model that averages the losses in deep peak shaving conditions has been discarded. Instead, new judgment criteria for conventional and various special operating conditions of thermal power units are established. The lifespan loss cost of the unit is integrated into the operating objective function and the corresponding constraint conditions are modified. Finally, a unit commitment model considering the multi-operating condition lifespan losses of thermal power units is constructed. Example simulations indicate that the conventional model underestimates the actual loss cost of the units. In constrast, the proposed model can not only reduce the operating cost and unit life loss by considering the lifespan impacts of multi-operating conditions, but also enhance the peak shaving capacity of thermal power units and promote wind power consumption.

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    Optimization Model for Safeguarding Vulnerable Components in Integrated Energy Systems Based on Weighted Betweenness
    ZHANG Chenwei, WANG Ying, LI Yaping, ZHANG Kaifeng
    Journal of Shanghai Jiao Tong University    2025, 59 (7): 923-937.   DOI: 10.16183/j.cnki.jsjtu.2023.403
    Abstract1987)   HTML3)    PDF(pc) (3112KB)(225)       Save

    Utilizing the complex network theory to mitigate vulnerabilities mitigation in integrated energy systems is significant for enhancing the resilience of sustained energy supply, especially against deliberate physical attacks and natural disasters. To implement more precise preventive measures for vulnerable components in integrated energy systems, this paper proposes a weighted betweenness-based protection optimization model for safeguarding vulnerable segments. The model aims to minimize the weighted betweenness loss incurred post attacks and damages, while simultaneously considering strategies such as establishing backup nodes and backup lines, enhancing physical protection of nodes and lines, and adding new lines. These strategies are subject to constraints such as protection requirements, budget limitations, and constraints on the types and quantities of new lines. The model optimization provides the optimal protection strategies within the allocated budget. To address the complex betweenness computations and non-linear objective functions, the model is formulated as a bilevel structure based on the nature of protection measures first. Then, the lower-level model is solved using a local linearization technique, and a “genetic-mixed integer linear programming” algorithm is proposed for solving the model with high precision and efficiency. The simulation results demonstrate that under conditions of equivalent attack and damage, the system with the optimal protection strategy achieves reduction of 45.37% in weighted betweenness loss compared with that without protection. The optimal strategy outperforms the other five protection strategies considered within the allocated protection budget.

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    Energy Services Demand Forecasting Combined with Feature Preferences and Bidirectional Long- and Short-Term Memory Networks
    KANG Feng, TAN Huochao, SU Liwei, JIAN Donglin, WANG Shuai, QIN Hao, ZHANG Yongjun
    Journal of Shanghai Jiao Tong University    2025, 59 (7): 1007-1018.   DOI: 10.16183/j.cnki.jsjtu.2023.458
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    Accurate and efficient demand forecasting of customer energy services is crucial for quality and risk management in grid customer service. Therefore, this paper proposes a user energy service demand prediction model based on feature selection. The methodology includes introducing a sampling algorithm to solve the class imbalance problem in the data on the basis of analysing the user energy service data, reducing the dimensionality of the data based on an autoencoder to ensure efficient clustering of the K-mean algorithm, constructing a feature selection algorithm based on a lightweight gradient lifting machine to filter the effective features and improve the training efficiency of the prediction model, and establishing a bidirectional long- and short-term memory neural network multi-label predicting model based on an attentional mechanism to refine the user’s energy service demand. Through the analysis of 720 000 work order data from Guangdong Power Grid over three years, showing that the model proposed can effectively improve the prediction accuracy and speed.

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    Preparation and Electromagnetic Properties of ZIF-67 Derived Carbon Spheres Loaded on Graphene
    LIU Zhenglin, ZHA Borui, WEI Bo, ZHOU Jintang, TAO Jiaqi, CHENG Zhenyu, LIU Jun, WU Fan
    Air & Space Defense    2024, 7 (6): 120-127.  
    Abstract1947)      PDF(pc) (2413KB)(789)       Save
    With the arrival of the 5G era, electromagnetic pollution has also become a new public concern, which has already received extensive attention from the social and scientific communities. Thus, it’s significant to develop materials with efficient microwave absorption properties. In this paper, a simple preparation method was used to uniformly load spherical ZIF-67 on graphene nanosheets, and a novel electromagnetic wave absorbing material consisting of twodimensional (2D) and three-dimensional (3D) materials was achieved after high-temperature annealing (spherical ZIF-67 derived carbon spheres loaded on graphene, Co@C/GNs ). Conductivity loss, natural resonance and exchange resonance in the low and middle-frequency bands, as well as polarization loss and eddy current loss in the high-frequency band, can together enhance the effective absorption of electromagnetic waves. Among them, wave absorbers with 5% graphene by mass of ZIF-67 have the best wave absorbing performance, with the minimum reflection loss value of − 31.66 dB at a matching thickness of 2.5 mm and the effective bandwidth up to 5.56 GHz at a matching thickness of 1.5 mm. This work provides an alternative option for the preparation of electromagnetic absorbing composites.
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    Reliability Allocation Method for Electric Aircraft Lightweight Propulsion System
    LI Jinghao, LI Ran, HUA Hao, HUANG Wentao, GAO Fei, TAI Nengling
    Journal of Shanghai Jiao Tong University    2025, 59 (6): 867-876.   DOI: 10.16183/j.cnki.jsjtu.2023.425
    Abstract1943)   HTML5)    PDF(pc) (2862KB)(384)       Save

    In order to solve the contradiction between lightweight and high reliability in the electric aircraft electric propulsion system, a reliability allocation method considering lightweight constraint is proposed for the first time. An analytical expression between weight and reliability is integrated into the electric propulsion system design model as constraints, and a flexible “weight-reliability” optimization method is proposed, considering the uncertainty of the operating conditions of electric aircraft. This method achieves minimum weight under reliability constraints and maximum reliability under weight constraints. Taking the “Spirit of Innovation” electric aircraft as an example, the results show that the proposed method can reduce the total weight of the power system of the electric aircraft by 3.5% while ensuring the reliability of the system. The applicability of the proposed method is verified in different scenarios designed, providing technical support for the development of high power-to-weight ratio in electric aircrafts.

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    Detection of Foreign Bodies in Transmission Line Channels Based on Fusion of Swin Transformer and YOLOv5
    XUE Ang, JIANG Enyu, ZHANG Wentao, LIN Shunfu, MI Yang
    Journal of Shanghai Jiao Tong University    2025, 59 (3): 413-423.   DOI: 10.16183/j.cnki.jsjtu.2023.301
    Abstract1940)   HTML9)    PDF(pc) (26717KB)(646)       Save

    To address the challenges of complex detection background and poor detection performance for small targets, a transmission line channel security detection algorithm based on the fusion of window self-attention network and the YOLOv5 model is proposed. First, the Swin Transformer (S-T) is employed to optimize the backbone network, expanding the perception field of the model and enhancing its ability to extract effective information. Then, the adaptive spatial feature fusion (ASFF) module is improved to enhance the feature fusion ability of the model. Finally, considering the mismatch between the real frame and the predicted frame, the structural similarity intersection over union (SIoU) is introduced to optimize the boundary errors and improve the generalization ability of the model. The experimental results show that the model proposed achieves a multi-target intrusion detection accuracy of 90.2%, and with significant improvements in the detection of small targets. This approach better meets the requirements of foreign object detection in transmission line channels compared to other object detection algorithms.

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    Digital Parallel Battlefield: A Review of Theory and Development Prospects
    ZHANG Sipei, XU Tianyang, KANG Chuanhua, CI Huipeng, LIU Rui
    Air & Space Defense    2025, 8 (3): 29-39.  
    Abstract1919)      PDF(pc) (1035KB)(360)       Save
    With the rapid development of information technology, modern warfare is transforming towards digitalisation, networking, and intelligence. As an advanced stage of the digital battlefield, the digital parallel battlefield leverages physical and virtual systems integration to provide innovative solutions for situational awareness, element coordination, and decision optimisation. This paper systematically reviewed the latest research on the digital parallel battlefield, analysing its theoretical foundations, military value, technical architecture, and practical applications. Key challenges within the field were identified, and future development trends were explored. The study highlighted the significant role of the digital parallel battlefield in enhancing joint operational capabilities, optimising command and control efficiency, and innovating military training models. In addition, challenges such as a lack of unified theoretical frameworks, delayed technical standards, and insufficient cross-domain coordination were given. In conclusion, with the continuous integration of artificial intelligence, big data, and other emerging technologies, the digital parallel battlefield will achieve broader applications in intelligence, collaboration, and service-oriented development.
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    Oscillatory Stability Assessment of Renewable Power Systems Based on Frequency-Domain Modal Analysis
    GAO Lei, MA Junchao, LÜ Jing, LIU Jianing, WANG Chenxu, CAI Xu
    Journal of Shanghai Jiao Tong University    2025, 59 (6): 821-835.   DOI: 10.16183/j.cnki.jsjtu.2023.358
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    The increasing penetration of the renewable energy has increased the risks of sub/super synchronous oscillations in power systems. Therefore, it is critical to accurately evaluate the oscillatory stability of renewable power systems ensuring the safe and stable operation of the systems. In this paper, a method for evaluating the oscillatory stability of renewable power systems based on frequency-domain modal analysis is investigated. First, the frequency-domain impedance or admittance models of key equipment and stations are established, including the renewable power generators and stations, transmission lines, synchronous generators, transformers, etc. Next, a system-level frequency-domain network model is constructed based on the actual system topology. Then, the oscillatory stability of the renewable power system is evaluated by solving the zeros of the determinant of the loop impedance matrix or the node admittance matrix of the system. The weak points of the system are identified using the participated matrix of the weak oscillation mode, which provides reference for implementation of oscillation suppression measures. Taking the practical renewable power system in East China as an example, the oscillatory stability of the system considering the varying access capacity of renewables under different grid operating conditions is assessed using the frequency-domain modal analysis method. Finally, the time-domain simulation model of the actual renewable power system is built in PSCAD/EMTDC to verify the theoretical analysis.

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    Reactive Power-Voltage Droop Gain Online Tuning Method of Photovoltaic Inverters for Improvement of Stable Output Power Capability in Weak Grids
    WANG Yuyang, ZHANG Chen, ZHANG Yu, WANG Yiming, XU Po, CAI Xu
    Journal of Shanghai Jiao Tong University    2025, 59 (6): 845-856.   DOI: 10.16183/j.cnki.jsjtu.2023.353
    Abstract1883)   HTML5)    PDF(pc) (7800KB)(1784)       Save

    The active power output capability and small signal stability in weak grids are key factors that limit stable photovoltaic (PV) power generation. To improve stably generating PV power in weak grids, an adaptive control method for PV inverters based on online tuning of the reactive power-voltage (Q-V) droop gain is proposed. First, to ensure active power output capability in weak grids, a “first optimization” method for the Q-V droop gain is proposed, considering voltage and current constraints. Then, to address stability constraints in weak grids, impedance modeling and stability analysis of the PV inverter system are conducted. A mapping relationship between the “parameter-weakest pole” is established with the weakest pole of the closed-loop system as a stability constraint based on the artificial neural network. A “second adjustment” method for the Q-V droop gain is developed at stably generating active power. Combined with the extended Kalman-filter-based grid impedance estimation, the proposed Q-V droop gain adaptive tuning method is realized. The effectiveness of the proposed adaptive control method is validated on the Modeling Tech real-time simulation platform.

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    Research Progress of Resin Matrix Composites for Air Defense Missiles
    CHEN Xue, ZHU Longyu, XUE Qinyang, WANG Kexiang, HAN Zhilin, LUO Chuyang
    Air & Space Defense    2024, 7 (6): 76-95.  
    Abstract1871)      PDF(pc) (3146KB)(2344)       Save
    Lightweight design is a dominant development trend in advanced air defense missile systems. Resin matrix composites, with the advantages of being lightweight, high strength, high-temperature resistant, corrosion-resistant, and designable, play a key role in promoting the lightweight design of missiles. This paper has reviewed the research progress and current applications of thermoset and thermoplastic composites in air defense missiles. It comprehensively provides an overview of the application progress and development prospects of resin matrix composites in typical missile components, offering insights into the future development of these materials.
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    DC-Bus Voltage Oscillation Suppressor Based on Active Capacitor and Its Control Method
    YANG Jipei, YANG Ling, WEI Maohua
    Journal of Shanghai Jiao Tong University    2025, 59 (3): 303-312.   DOI: 10.16183/j.cnki.jsjtu.2023.327
    Abstract1870)   HTML21)    PDF(pc) (8081KB)(289)       Save

    The constant power load (CPL) in a DC microgrid can reduce the effective damping of the system, resulting in high frequency voltage oscillations on the DC bus, which threatens the safe and stable operation of the system. To address this issue, this paper proposes a DC-bus voltage oscillation suppressor based on an active capacitor and its control method. The oscillation suppressor is connected in parallel to the DC bus, enabling direct interaction with the DC bus. The energy storage capacitor in the oscillator suppressor effectively stores the transient energy generated by voltage oscillations, thereby reducing the amplitude of voltage oscillation and improving the voltage stability of the bus. The voltage of the power supply in the oscillation suppressor adapts to the voltage of the DC bus, allowing for stable operation in the face of load changes in the system. The design offers advantages such as plug-and-play functionality, strong applicability, and flexible control. In addition, by analyzing the operating mode and mechanism of the oscillation suppressor, a small signal model is established, and the influence of controller parameters on the stability and dynamic performance of the suppressor is analyzed, based on which the controller parameter optimization scheme is proposed. Finally, the effectiveness of the oscillatory suppressor is validated through the experimental results.

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    Multi-Objective Optimization Design of Micro-Site Selection of Complex Terrain Wind Farms Assisted by Proxy Model
    LIU Jiahui, WANG Cong, ZHANG Hongli, MA Ping, LI Xinkai, DONG Yingchao
    Journal of Shanghai Jiao Tong University    2025, 59 (9): 1315-1326.   DOI: 10.16183/j.cnki.jsjtu.2023.486
    Abstract1868)   HTML5)    PDF(pc) (5456KB)(1175)       Save

    To tackle the challenges of high difficulty and time-consuming micro-site optimization of wind farms in complex terrains, a multi-objective optimization method for micro-site selection is proposed, assisted by proxy model. First, considering the geographical features of complex terrains with significent undulations, the ruggedness index is calculated and the ground flatness is numerically quantified, constraining the points with excessive ruggedness. Then, a mathematical model for three-dimensional windy downward wake superposition calculation of power generation is established, a three-dimensional terrain collector line topology optimization agent model is constructed, and the prediction accuracy of the proxy model is verified, demonstrating the ability to replace numerous calculations in collector line topology optimization and effectively improving the computing efficiency. Finally, taking a real complex terrain wind farm in Xinjiang Uygur Autonomous Region, China as an example, multi-objective micro-site selection of complex terrain wind farm is realized, and the results are compared with those obtained through the single-objective optimization. The simulation results show that the multi-objective discrete state transfer algorithm assisted by the proxy model can reduce the total cable laying length, decrease the construction costs, and provide more feasible layout schemes while optimizing the annual power generation.

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    Optimal Design Method of Complex System Based on Resource Optimization
    ZHANG Rongfu, WANG Jinqiang, LIU Minxia
    Air & Space Defense    2025, 8 (3): 86-94.  
    Abstract1867)      PDF(pc) (991KB)(60)       Save
    To solve the resource optimisation problem in the modular design of complex systems, a hybrid optimisation method combining fuzzy C-means clustering, genetic algorithm, simulated annealing, and immune selection mechanism was proposed in this study. This method first used the fuzzy C-means clustering algorithm to analyse the correlation between component functional structures, generating initial module partitions. Then, it optimised the module partitions using an improved genetic algorithm. The integration of simulated annealing significantly enhanced the local search ability of the algorithm. At the same time, the immune selection mechanism maintained population diversity through operations including elite retention, gene exchange, and insertion mutation, further improving the algorithm's global search ability and stability. The results show that the proposed method significantly optimises the cohesion and coupling of modules and can effectively improve the quality and efficiency of modular design. In addition, the process presents an ideal balance between calculation speed and optimisation accuracy, which is particularly suitable for industrial scenarios having high requirements for independence, scalability and cost control.
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    Damage Monitoring Method for Deep-Sea Net Cage Rope Structure Based on Tension Signal
    YANG Mengjie, REN Haojie, REN Hao, XU Yuwang, ZHANG Mengmeng
    Journal of Shanghai Jiao Tong University    2025, 59 (4): 550-560.   DOI: 10.16183/j.cnki.jsjtu.2023.372
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    The net system is an important component of the deep-sea net cages. As the bone structure of the net system, the rope structure bears the main hydrodynamic load of the net system, making the monitoring its health status essential. Aiming at the online damage monitoring of the rope structure, a finite element numerical model of the rope structure is developed, and the mechanical properties of the rope structure under intact and damaged conditions are compared and analyzed. The results show that when the rope is damaged, the end tension load of the damaged rope decreases sharply, while the end tension load of the adjacent rope increases. Based on the characteristics of these sudden tension changes and the influence of the damaged rope on the load of undamaged rope, three damage identification parameters are defined as the tension correlation coefficient, the total influence value, and the tension variation coefficient of the rope structure. Additionly, an online damage monitoring method based on rope tension signal is proposed. This method identifies the damaged rope by detecting an extremum step in the tension variation coefficient, and determines the specific damaged position by analyzing the proportion relationship between the tension change coefficient and the distance from the end to the damaged position. The research provides a reliable method for online monitoring of rope structure damage for the healthy operation and maintenance of deep-sea net cages.

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    Multi-Objective Optimization Design of Ship Propulsion Shafting Based on Response Surface Methodology and Genetic Algorithm
    ZHANG Cong, SHU Bingnan, ZHANG Jiangtao, JIN Yong
    Journal of Shanghai Jiao Tong University    2025, 59 (4): 466-475.   DOI: 10.16183/j.cnki.jsjtu.2023.318
    Abstract1833)   HTML11)    PDF(pc) (9630KB)(837)       Save

    In order to reduce the power loss of the transmission equipment, enhance the transmission efficiency of the propulsion shafting, and improve the vibration performance of the shafting, a multi-objective optimization design of a ship shafting experimental platform is performed based on the response surface model and genetic algorithm. The central composite design (CCD) method is used to select appropriate experimental points in the optimized design space, and the response surface model is developed with minimum total power consumption and vibration response amplitude. Based on the genetic algorithm, the Pareto optimal solution of response surface model regression function is solved through MATLAB software. The optimal design scheme is obtained by comparing and analyzing several groups of optimization results. The results show that the combined method can reduce the power loss of shafting by approximate 7.10% and reduce the vibration amplitude of shafting by 2.30%, while significantly improving the shafting transmission efficiency and effectively suppressing the vibration problem of propulsion shafting. The fiudings validate the feasibility of the multi-objective optimization method for the ship propulsion shafting.

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    Irregular Wave Groups Simulation Based on Semi-Mixed Eulerian-Lagrangian Boundary Element Method
    XUE Wen, GAO Zhiliang
    Journal of Shanghai Jiao Tong University    2025, 59 (4): 435-446.   DOI: 10.16183/j.cnki.jsjtu.2023.302
    Abstract1830)   HTML13)    PDF(pc) (3375KB)(204)       Save

    In order to effectively simulate irregular wave groups that better represent the characteristics of real waves, a numerical wave tank based on a semi-mixed Eulerian-Lagrangian algorithm combined with boundary element method was developed in conjunction with a theoretical generation method for irregular wave groups. First, the impact of model parameters on the numerical solution was analyzed. The results showed that the accuracy of wave simulation improved with an increase in damping layer length or a decrease in the time step. Additionly, selecting appropriate deviation distance, distribution range, and the number of source points can balance computation accuracy and stability. Then, unidirectional irregular wave groups were simulated based on the verified model parameters. The numerical results were compared with the physical test data and theoretical values to validate the performance of the numerical tank in simulating irregular wave groups. The findings indicated that the developed numerical wave tank can effectively simulate the generation and propagation of irregular wave groups.

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    A Fault Diagnosis Method for Wind Turbines Based on Zero-Shot Learning
    PAN Meiqi, HE Xing
    Journal of Shanghai Jiao Tong University    2025, 59 (5): 561-568.   DOI: 10.16183/j.cnki.jsjtu.2023.375
    Abstract1828)   HTML14)    PDF(pc) (1123KB)(1293)       Save

    In engineering practice, wind turbine fault diagnosis encounters situations where the fault category in the training data is different from the actual one. To diagnose unknown wind turbine faults, it is necessary to transfer the fault feature information learned during training to the unknown fault category. Unlike traditional methods that directly establish mapping between fault samples and fault categories, a zero-shot learning (ZSL) method for wind turbine fault diagnosis based on fault attributes is proposed to enable fault feature migration. A fault attribute matrix is established by describing the attributes of each fault, which is embedded into the fault sample space and fault category space. Then, a fault attribute learner is developed based on convolutional neural network (CNN), and a fault classifier is established based on Euclidean distance, forming the diagnosis process where fault attributes are predicted from fault samples and then classified. Finally, the effectiveness and superiority of the proposed fault diagnosis method are validated by comparing it with other zero-shot learning methods.

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