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    Modeling and Sliding Mode Control for Chaotic Yawing Phenomenon of Large Oil Tanker
    ZHANG Xianku, HAN Xu
    Journal of Shanghai Jiao Tong University    2021, 55 (1): 40-47.   DOI: 10.16183/j.cnki.jsjtu.2019.104
    Abstract693)   HTML2)    PDF(pc) (1255KB)(551)       Save

    In order to explain and control the unexpected yawing phenomenon of large oil tankers, a pilot model is used to replace the original proportional model and is combined with the nonlinear ship responding model to construct a model of the whole closed-loop maneuvering system, which is found to be similar to the chaotic Duffing equation, and to be able to have a positive Lyapunov exponent after parameter adjustment, indicating that the chaotic theory can be used to explain this unexpected yawing phenomenon. In order to realize course keeping control with robustness to parameter uncertainty, based on the model built and the backstepping method, a sliding mode control scheme is proposed. The simulation illustrates that the static state rudder angle is smaller than 5° and course deviation is smaller than 0.07° when the chaotic yawing is at the theoretical maximum. Chaotic yawing is eliminated. The idea of establishing man-in-the-loop chaotic system is novel, and the method of solving backstepping parameter uncertainty through sliding mode is easy and effective.

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    Optimization of Subgrade Structure Parameters of Ballasted Track Passenger Dedicated Line
    WANG Wei, LU Sikui, YANG Chengzhong, FENG Qingsong
    Journal of Shanghai Jiao Tong University    2021, 55 (1): 48-55.   DOI: 10.16183/j.cnki.jsjtu.2019.235
    Abstract699)   HTML1)    PDF(pc) (1643KB)(290)       Save

    In order to improve the force condition of ballasted railway subgrade structure and reduce maintenance cost, it is necessary to study the influence of subgrade structure parameters on subgrade dynamic response under train load. Orthogonal test was designed and used to analyze the sensitive relationship between dynamic response of railway subgrade structure and parameters of each structural layer, and the optimal parameter combination of subgrade structure of ballasted railway was determined by combining analytic hierarchy process (AHP) and linear evaluation index. The parameters include elastic modulus of ballast bed, elastic modulus of surface and bottom layer of subgrade bed, thickness of ballast bed, thickness of surface and bottom layer of subgrade bed, and elastic modulus of foundation. The results show that the thickness of track bed is the main factor that affects dynamic stress of ballast bed, dynamic stress and vibration acceleration of surface layer of subgrade bed. The elastic modulus of foundation is the main factor that affects the vertical displacement of the sleeper. The mechanical optimum parameter combination of ballast track structure parameters is determined as the elastic modulus ballast bed is 250 MPa, elastic moduli of surface and bottom layer of subgrade bed are 120 MPa and 115 MPa, the thickness of ballast bed is 0.35 m, the thickness of surface and bottom layer of subgrade bed are 1.1 m and 2.3 m, and the elastic modulus of foundation is 70 MPa.

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    Design and Test of a Magneto-Rheological Mount Applied to Start/Stop Mode of Vehicle Powertrains
    DENG Zhaoxue, YANG Qinghua, CAI Qiang, LIU Tianqin
    Journal of Shanghai Jiao Tong University    2021, 55 (1): 56-66.   DOI: 10.16183/j.cnki.jsjtu.2019.192
    Abstract832)   HTML4)    PDF(pc) (6695KB)(394)       Save

    In order to overcome the disadvantage of vehicle ride comfort caused by large vibration and torque excitation of vehicle engine in start/stop mode, a flow mode magneto-rheological (MR) mount is designed for low frequency working conditions. Based on the analysis on the influence of exciting current on the viscosity of the MR fluid (MRF) and the relationship between the fluid resistance effect and the flow rate in the damping channel, the magnetic circuit and the damping performance of the MR mount model are analyzed. According to the mathematical model of the MR mount damping force, the multi-objective optimization function of the magnetic circuit is established. The co-simulation optimal platform is developed by using the Isight and ANSYS software. The non-dominated sorting genetic algorithm II (NSGA-II) is used to optimize magnetic circuit design. The dynamic performance test of the MR mount monomer and the vibration isolation performance test of the whole vehicle in start/stop mode are conducted respectively. The results show that the controllable damping force of the optimized MR mount increases by 111.71% and the restoring force increases by 21.99% compared with those before. When the vehicle is in start/stop mode and the excitation current is 1.0A, the peak vibration acceleration of the passive side (the side connected to the body) with the optimized MR mount decreases by 33.3% compared with that before. Besides, the peak vibration acceleration of driver’s seat rail decreases by 21.6%, which significantly improves the ride comfort of the vehicle.

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    Control Strategy for Electric Vehicle Range-Extender Based on Hybrid Excitation Generator
    HOU Jue, YAO Dongwei, WU Feng, LÜ Chenglei, WANG Han, SHEN Junhao
    Journal of Shanghai Jiao Tong University    2021, 55 (2): 206-212.   DOI: 10.16183/j.cnki.jsjtu.2019.203
    Abstract887)   HTML7)    PDF(pc) (2119KB)(612)       Save

    Based on a hybrid excitation generator, a novel electric vehicle range-extender was proposed and the control system structure and the working principle were described. The multi-speed point working area was determined, according to the overall efficiency characteristics of the hybrid excitation range-extender. Based on the flexible adjustable characteristics of the air-gap magnetic field of the hybrid excitation generator, a double-closed-loop generation control algorithm was designed by decoupling the speed-power around the working area of the range-extender. The control strategy model was built by using MATLAB/Simulink and verified based on the prototype of the self-developed hybrid excitation range-extender. The test results show that the hybrid excitation range-extender has fast-dynamic response of output power and small steady-state error of speed and power control. Further, the steady-state and transient operating conditions are both located in the set working area. Therefore the power generation control strategy is feasible.

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    Development of a Hybrid Solar and Wind-Powered Long-Range Unmanned Ocean Stereo Exploration Vessel
    YAO Tiancheng, ZHAO Yongsheng, WANG Hongyu, HE Yanping, DING Zilong, CHI Zheying, CAI Weikai
    Journal of Shanghai Jiao Tong University    2021, 55 (2): 215-220.   DOI: 10.16183/j.cnki.jsjtu.2020.352
    Abstract1088)   HTML11)    PDF(pc) (10222KB)(626)       Save

    Aimed at the problems of unmanned marine exploration vessels, such as the short voyage time and the limited sensing ability caused by sensor failure under complex marine environments, a long-range unmanned ocean-air stereo exploration vessel driven by wind and solar energy is developed. An elevating ducted wind turbine is designed for high efficiency and low starting wind speed, and a deployable solar photovoltaic power generation system is developed. Therefore, wind power and solar energy can be utilized to realize a hybrid system, which overcomes the instability of single energy power supply, and effectively ensures the endurance of unmanned exploration vessel. Then, a ship-borne tethered ummanned aerial vehicle (UAV) system is developed with an autonomous takeoff and landing control section. Finally, the information fusion technology of ship borne and airborne sensors is adopted to greatly improve the perception ability of the unmanned ship to the surrounding environment and the function of three-dimension detection of sea and air. The unmanned surface vessel (USV) proposed in this paper is permitted to perform the assigned task with different types of loading equipment according to the scenarios.

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    Research and Test Verification of Dynamic Characteristics of Deck V-Arch Bridge
    XIE Xiaoli, PANG Mulin, QIU Chen, QIN Shisheng
    Journal of Shanghai Jiao Tong University    2021, 55 (3): 276-289.   DOI: 10.16183/j.cnki.jsjtu.2019.284
    Abstract818)   HTML0)    PDF(pc) (11860KB)(264)       Save

    To solve the problem that the natural frequency of deck arch bridges would decrease rapidly when the span increases, a novel arch bridge structure named deck V-arch bridge is proposed. The V-shaped members are added between the main girders and the arch ribs to increase the stiffness of the arch bridge, thereby increasing the natural frequency of the structure. Through the timely conversion of the structural system, the first-phase dead load is carried by the arch ribs, while the second-phase dead load and live load are carried by the variable height truss with main girders as upper chords, arch ribs as lower chords, and V-shaped members as webs, with multi-point elastic constraints. The entire structure has the advantages of arch and truss. In order to verify the correctness of the research and calculation of the dynamic characteristics of the deck V-arch bridge, a test bridge with a span of 10 m is built. The first natural frequency of the vertical bending in the plane of the bridge is tested by utilzing the pulsation test. The stiffness and dynamic characteristics are calculated by utilizing the finite element software. The influence of V-shaped member stiffness on the natural frequency and that of the number of V-shaped members on the temperature stress of the structure are analyzed. The necessity of system transformation is studied. The results show that the difference between test value and calculated value of the first natural frequency of vertical bending in the plane is small. The mode shape is in good agreement with the finite element analysis. With little or no additional material, the natural frequency of the structure is significantly increased, especially the in-plane frequency. The stiffness of the V-shaped members has a reasonable setting range. When the inner angles of the triangle formed by the main girders or the arch ribs are between 45 ℃ and 60 ℃,the number of V-shaped web members is suitable. The structural stiffness of deck arch bridge with V-shaped members is greatly improved, and at the position of L/4 (L is the span of the bridge), the upward deflection generated by the static live load of the train is approximately zero. After the transformation of the structural system, the deck V-arch bridge can fully exert the superiority of the arch force.

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    Physics-Based Simulation of AUV Forced Diving by Self-Propulsion
    WU Lihong, FENG Xisheng, YE Zuolin, LI Yiping
    Journal of Shanghai Jiao Tong University    2021, 55 (3): 290-296.   DOI: 10.16183/j.cnki.jsjtu.2019.191
    Abstract647)   HTML6)    PDF(pc) (4426KB)(387)       Save

    It is necessary to predict accurately the maneuverability of autonomous underwater vehicle (AUV) diving by self-propulsion to improve its safety and stability. A method was presented to predict the vehicle’s forces and flow details in real time during forced diving motion. A full appended model was built, the propeller’s rotating motion was simulated, and coupled with user defined function (UDF), the Reynolds-averaged Navier-Stokes (RANS) equations were solved. This method can improve the accuracy and computation efficiency of the dynamic mesh method by using multi-block mesh with the moving zone method. The numerical method was validated by comparison of the computational and experimental results of AUV’s velocity in AUV self-propulsion test. The numerical results of AUV forced diving by self-propulsion showed that, at the initial time, the AUV had a large acceleration which resulted in a large resistance. When the pitch changed, the vertical force oscillated. The wake of the propeller twisted and the thrust of the propeller varied. In steady diving, the thrust and resistance became steady.

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    Heterogeneous Tramp Ship Scheduling and Speed Optimization with Fuzzy Time Window
    FAN Houming, YU Jiaqi, MA Mengzhi, JIANG Xiaodan, CI Jili, ZHAI Zhiwei
    Journal of Shanghai Jiao Tong University    2021, 55 (3): 297-310.   DOI: 10.16183/j.cnki.jsjtu.2019.215
    Abstract664)   HTML1)    PDF(pc) (1672KB)(316)       Save

    In order to improve the cargo owner’s satisfaction and obtain better economic benefits for shipping companies, the ship deployment along routes and speed optimization of tramp ships are studied, considering the influencing factors of ship scheduling with the configuration and speed of self-owned ships and chartered ships. A goal is developed by minimizing sailing cost, fuel, and waiting cost at ports, penalty cost for late arrival at ports, time cost, and voyage ship chartering cost by applying fuzzy time window to characterize the cargo owner’s satisfaction. The model of scheduling and speed optimization with fuzzy time window for heterogeneous tramp ships is established. A variable neighborhood genetic simulated annealing (VNGSA) algorithm is presented to solve the problem. First, the ship type is matched with the cargo. Then the route is generated according to the time constraint. Finally, the neighborhood search strategy is adopted to improve the solution quality. Computational results indicate that integrated planning for ship scheduling and speed can reduce sailing cost; considering time requirement of cargo owners can increase their satisfaction. This paper can enrich tramp ship routing and speed optimization problems and provide a theoretical tool for shipping companies to make related decisions.

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    Ice Floe Trajectory Under the Action of Propeller Pumping
    WANG Chao, YANG Bo, WANG Chunhui, GUO Chunyu, XU Pei
    Journal of Shanghai Jiao Tong University    2021, 55 (5): 505-512.   DOI: 10.16183/j.cnki.jsjtu.2019.365
    Abstract616)   HTML9)    PDF(pc) (8916KB)(284)       Save

    In order to study the influence of propeller pumping action on ice trajectory during the process of ice propeller interference, this paper built a motion trajectory measurement platform based on circulating water tank, combining high-speed camera and the Photron FASTCAM Analysis (PFA) method, and tested and analyzed the trajectory of ice at different propeller rotation speeds. After systematic analysis of the test results, it is found that when the propeller rotates at a high speed and the flow velocity is small, the pumping action effect is obvious, which apparently changes the model ice trajectory and even makes the ice and propeller collide. When the model ice volume is large and the water flow velocity is fast, the propeller pumping action effect is small, and it is difficult for the pumping action effect to change the ice trajectory because of the influence of the water flow velocity, which has little effect on the model ice motion trajectory.

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    Simulation of Undercooling Influence on Shape and Velocity of Seawater Freezing Process Using Phase Field Method
    BAI Xu, YANG Sujie
    Journal of Shanghai Jiao Tong University    2021, 55 (5): 513-520.   DOI: 10.16183/j.cnki.jsjtu.2020.077
    Abstract741)   HTML11)    PDF(pc) (4210KB)(456)       Save

    In order to study the microcosmic mechanism of ice formation in ship structure, a numerical simulation is conducted. Based on the Wheeler phase field model, the finite difference method is used to simulate the solidification shape of seawater at different undercoolings. In the process of simulation, sea water is regarded as the binary mixture of salt and pure water, and the authenticity of ice crystal growth is ensured by setting ice physical parameters and introducing crystal nucleus. In the calculation, four nuclei are set up to simulate the ice crystal growth, and the influence of different undercoolings on the ice crystal growth is discussed. The results show that the growth rate of ice crystal increases with the increase of undercooling, and it is linear with the change of undercooling. When the dimensionless undercooling is less than 0.85, the dendrite has only a few branches which are thin. When the dimensionless undercooling is higher than 0.85, the ice crystal has more than two-stages of branches which are obviously thicker. When the dimensionless undercooling reaches 1.0, the branches are squeezed by the main branches and lessned, and the crystal cores are finally filled.

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    Numerical Investigation of Three-Dimensional Shallow-Water Sloshing Based on High Accuracy Boussinesq Equations
    YUAN Xinyi, SU Yan, LIU Zuyuan
    Journal of Shanghai Jiao Tong University    2021, 55 (5): 521-526.   DOI: 10.16183/j.cnki.jsjtu.2020.053
    Abstract598)   HTML9)    PDF(pc) (1430KB)(481)       Save

    Highly accurate Boussinesq-type equations in terms of velocity potential are used for the simulation of shallow-water sloshing in a three-dimensional tank under the framework of the potential flow theory. The total velocity potential is separated into two parts: one part is a particular solution which satisfies the Laplace equation in the fluid domain and the no-flow condition on the walls while the other part is solved by the Boussinesq-type model. In the process of numerical calculation, the finite difference method is used for spatial derivative discretization and the 4th Runge-kutta method is used for time iteration. To verify the numerical model, the aspect ratio of the tank is set to be much less than 1 for simulation of 2D cases and is compared with the results published. In the 3D cases, four different sloshing motion forms are observed at each external excitation frequency, and a corresponding number of traveling waves are observed on the free surface. Moreover, the effects of external excitation frequency and coupling excitation on the sloshing motion in the tank are discussed.

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    Method for Plate Crack Damage Detection Based on Long Short-Term Memory Neural Network
    ZHANG Songlin, MA Dongliang, WANG Deyu
    Journal of Shanghai Jiao Tong University    2021, 55 (5): 527-535.   DOI: 10.16183/j.cnki.jsjtu.2020.095
    Abstract624)   HTML15)    PDF(pc) (1411KB)(286)       Save

    Aimed at the problem of intelligent classification of crack damage in different positions of the plate, a method for plate crack damage detection based on long short-term memory (LSTM) neural network is proposed. The Abaqus secondary development is used to build the plate crack damage model and calculate the acceleration response of the plate under Gaussian white noise excitation. The data set is generated by data augmentation, and the influence of noise on damage detection is considered. An intelligent crack detection model based on LSTM is established, which directly takes the acceleration response of the plate as the input and does not require additional damage feature extraction. With the goal of minimizing prediction error, the hyperparameter of the model is selected and the model configuration is optimized. The comparison of the multi-layer perceptron model and the multi-layer perceptron model based on wavelet packet transform shows that the LSTM model proposed in this paper has a higher damage location accuracy and a better applicability in plate crack detection.

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    Multi-Scale Reliability-Based Design Optimization of Three-Dimensional Orthogonal Woven Composite Fender
    TAO Wei, LIU Zhao, XU Can, ZHU Ping
    Journal of Shanghai Jiao Tong University    2021, 55 (5): 615-623.   DOI: 10.16183/j.cnki.jsjtu.2019.283
    Abstract618)   HTML8)    PDF(pc) (7652KB)(325)       Save

    Three-dimensional orthogonal woven composites have excellent mechanical properties and delamination resistance, which have a bright future in the application of automotive lightweight. A prediction model of elastic properties for three-dimensional orthogonal woven composites was established based on the analytical micromechanical method. The macro-scale performances of the fender were analyzed by using the finite element method. The Monte Carlo reliability analysis method, the Kriging surrogate mode, and the particle swarm optimization algorithm were adopted to conduct multi-scale reliability-based design optimization of a composite structure, which involves the uncertainties of material and structural design variables. The results show that the optimized fender meets the requirments of structural stiffness and reliability, and it also achieves a weight reduction of 21.93%.

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    Design of Light Fireproof Enclosure Bulkheads Based on Topography Optimization for Cruise Ships
    ZHANG Fan, YANG Deqing, QIU Weiqiang
    Journal of Shanghai Jiao Tong University    2021, 55 (10): 1175-1187.   DOI: 10.16183/j.cnki.jsjtu.2020.201
    Abstract844)   HTML571)    PDF(pc) (19957KB)(839)       Save

    In order to develop a new lightweight enclosure structure with an excellent fireproof and bearing performance, and to replace the traditional stiffened fire enclosure bulkheads in the superstructure area, a design method of light fireproof enclosure bulkheads for cruise ship based on the topography optimization technology was proposed. The location and numbers of corrugated beads in lightweight wall designed by this method were generated according to the requirements of load bearing capacity and manufacturing process, and this method overcomes the disadvantages that the location and numbers of beads in the design of conventional corrugated wall have to be determined in advance. Aimed at the specified design regions, the lightweight of cruise fireproof enclosure bulkheads (CFEB) structure was taken as the objective function while the stress in the weld zone, the stress in the nonweld zone, and the first-order buckling factor of CFEB were taken as constraints. Then, the topography design models of CFEB were established and solved. Feasible configurations were obtained by topography optimization, and the final configurations of CFEB were formed by secondary design. The mechanical properties of the final configurations were compared with the traditional stiffened fireproof bulkheads. It is concluded that the new CFEB has advantages of lightweight and good strength compared with the traditional stiffened fireproof bulkheads.

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    Surge-Suppression Power Supply System for Ship High Power Pulse Loads
    PANG Yu, HUANG Wentao, WU Jun, TAI Nengling, SUN Guoliang
    Journal of Shanghai Jiao Tong University    2021, 55 (10): 1197-1209.   DOI: 10.16183/j.cnki.jsjtu.2020.358
    Abstract793)   HTML185)    PDF(pc) (2640KB)(616)       Save

    This paper analyzes the characteristics and influences of new pulse loads of ships. The surge-suppression power supply system for high power and multi-mode pulse loads, the capacitance and inductance calculation methods for the energy buffer unit are proposed, which can realize the power suppression, energy grouping, harmonic control and support backup, so that the safety of the ship power station and high precision power supply for loads can be ensured. The integrated power system simulation model of a new survey ship with high power radar loads is established in MATLAB/Simulink to verify the effectiveness of the surge-suppression power supply system at different modes. The system can not only reduce the impact of impulse load on the system, but also effectively suppress the system voltage harmonics, thus solving the key technical difficulties in the application of high power pulse loads to the independent power system.

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    Structural Impact Dynamic Response Characteristics of Offshore Platform Blast Wall in High Temperature Environment
    WANG Rui, XUE Hongxiang, YUAN Yuchao, TANG Wenyong
    Journal of Shanghai Jiao Tong University    2021, 55 (8): 968-975.   DOI: 10.16183/j.cnki.jsjtu.2019.249
    Abstract534)   HTML7)    PDF(pc) (7696KB)(268)       Save

    The blast wall is an important protection facility for offshore platforms, whose anti-explosion performance needs to be focused on. Based on the nonlinear finite element method, the structural dynamic response of the blast wall under the explosion at normal temperature was studied. The applicability of the quasi-static and dynamic algorithms was compared with the experimental data, and the structural impact deformation forms at room temperature were analyzed. Considering the effects of high temperature on materials and structures, the structural dynamic response characteristics of the blast wall were analyzed. The study shows that the high temperature has a significant aggravating effect on structural response. That is, given the load level, the maximum displacement can reach 5 times of that at normal temperature. Under the impact of normal temperature load, the structural strain is elastic with no permanent deformation or with small deformation, but it may aggravate to huge permanent deformation at a high temperature. The effect of high temperature will change the response pattern of the structure. This research can provide reference for the design of blast wall.

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    Numerical Simulation of Propeller Cavitation in Non-Uniform Flow
    LIU Heng, WU Rui, SUN Shuo
    Journal of Shanghai Jiao Tong University    2021, 55 (8): 976-983.   DOI: 10.16183/j.cnki.jsjtu.2020.211
    Abstract653)   HTML10)    PDF(pc) (20891KB)(512)       Save

    Taking a certain oil tanker propeller as the research object, and using Schnerr-Sauer cavitation model based on Rayleigh-Plesset equation and the realizable k-ε two-layer turbulence model, the cavitation pattern around the propeller in non-uniform flow conditions is simulated by using the computational fluid dynamics (CFD) software STAR-CCM+. Through effective and reasonable mesh densification of the propeller blade tip area, the tip vortex cavitation is successfully captured with a small number of meshes. The comparison between numerical calculation and test results shows that the whole process of cavitation inception, development, and collapse in wake flow can be accurately reproduced. The back-sheet cavitation pattern at each phase angle is in good agreement with the test results and the difference of cavitation area between calculation and the experiment is within 5%. Although the numerical method can capture the tip vortex cavitation, it cannot accurately predict the unsteady characteristics and spatial structure of the tip vortex cavitation. Based on the above results, it can be concluded this numerical methodology is suitable for simulating cavitation flows around propeller in non-uniform flow.

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    Extreme Response Analysis of Parametric Roll of C11 Container Ship
    ZHOU Xiaoyu, LI Hongxia, HUANG Yi
    Journal of Shanghai Jiao Tong University    2021, 55 (8): 984-989.   DOI: 10.16183/j.cnki.jsjtu.2020.085
    Abstract588)   HTML8)    PDF(pc) (830KB)(329)       Save

    Based on the narrow-band stochastic processes theory and Hermite transform, this paper proposed a method to study the extreme dynamic response of the parametric roll of ships. Taking the C11 container ship as an example, the average extremum of the stochastic parametric roll of the ship was estimated. A comparison of the results of Monte Carlo simulation indicates that the estimation error is lower than 1%, which proves that the proposed method is valid. Meanwhile, the prediction accuracy of the proposed method in this paper by using 20 time history samples is the same as that of the Monte Carlo method by using 104 time history samples, which proves the efficiency of the proposed method. Then, the conventional Gumbel model was used to estimate the extremum of the C11 parametric roll. A comparison of the results shows that the estimation error of the conventional Gumbel model is quite large, proving that the conventional Gumbel model is not appropriate to estimate the extreme responses of strong non-linear motions, such as the parametric roll of ships. However, even if the proposed method is used to predict extreme values, there is a certain deviation from the model test results. The analysis indicates that this prediction error is caused by ignoring the correlation between the maximum values.

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    Influence of Free-State Ice Size and Initial Position on Coupled Hydrodynamic Performance of Ice Propeller
    WANG Chao, LIU Zheng, LI Xing, WANG Chunhui, XU Pei
    Journal of Shanghai Jiao Tong University    2021, 55 (8): 990-1000.   DOI: 10.16183/j.cnki.jsjtu.2019.262
    Abstract501)   HTML5)    PDF(pc) (10307KB)(312)       Save

    In order to simulate the effect of free-moving ice on the hydrodynamic performance of the propeller, a non-contact model of ice-impeller interaction was established by using the overlapping grid method. In the calculation process, the hexahedral mesh was used to conduct mesh division of the computational domain, and the dynamic fluid body interaction (DFBI) method was used to simulate the motion of ice blocks under the propeller suction effect. The accuracy of the numerical method is verified by the experimental study on the action of the ice under the influence of the ice propeller. On this basis, the influences of different parameters such as ice size, the initial radial position of ice, and the initial axial position on the hydrodynamic performance of the propeller are obtained. The results show that there are a certain accelerating area and a certain blocking area behind the moving ice block. The size of ice block has a direct influence on the hydrodynamic performance of the propeller.

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    Energy Management of Parallel Ship Power System Based on Improved Fuzzy Logic Control
    WANG Ruichang, CHEN Zhihua, MING Xinguo
    Journal of Shanghai Jiao Tong University    2021, 55 (10): 1188-1196.   DOI: 10.16183/j.cnki.jsjtu.2020.043
    Abstract553)   HTML186)    PDF(pc) (1546KB)(454)       Save

    In order to alleviate the environmental pollution caused by ship transportation, an energy management strategy of parallel ship power system based on improved fuzzy logic control is proposed for the parallel hybrid power system with diesel engines as the main propulsion device. Based on the fuzzy logic control strategy, the error between required power and output power is used as a modification item and the sum of modification item, and demand power is taken as the input of the fuzzy logic control. By changing the fuzzy rules of excitation, the output power of the diesel engine and the output power of the battery pack are redistributed, so that the error between the total output power and the actual demand power is reduced. Energy management decisions can be made easily and quickly under different conditions by using this method which provides a new solution for energy management of high-power ship power systems.

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    Adaptive Internal Model Control for Automotive Steer-by-Wire System with Time Delay
    LIU Wentong, CHEN Li, CHEN Jun
    Journal of Shanghai Jiao Tong University    2021, 55 (10): 1210-1218.   DOI: 10.16183/j.cnki.jsjtu.2020.182
    Abstract582)   HTML17)    PDF(pc) (3780KB)(380)       Save

    Aimed at the unknown and uncertain time delay in the steer-by-wire system, an adaptive control strategy is designed based on the internal model control framework to improve the tracking accuracy of the steering angle. Without inducing non-minimum terms, a novel nominal model is established by connecting the model of the steer-by-wire system and the linearized delay model using the all pole approximation method. The Kalman filter algorithm is designed to identify the nominal model parameters and to update in real time. Thereafter, the parameters in the inverse controller of internal model controller are tuned online. The simulation and bench test results show that compared with the traditional internal model control whose inverse control discards time delay and the classical proportion integration differentiation (PID) control, the proposed adaptive internal model control considering time delay can obtain a better tracking accuracy and has a stronger adaptability to the change of time delay.

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    Design of Three-Dimensional Layout of Ship Engine Room Equipment Based on Knowledge Based Engineering
    WANG Yunlong, JIANG Yunbo, GUAN Guan, XING Jiapeng, YU Guangliang
    Journal of Shanghai Jiao Tong University    2021, 55 (10): 1219-1227.   DOI: 10.16183/j.cnki.jsjtu.2020.136
    Abstract855)   HTML25)    PDF(pc) (5639KB)(557)       Save

    The layout design of ship engine room equipment belongs to the multi-objective optimization design problem of confined limited space. As the heart of the ship, the layout of engine room equipment will affect the performance of all aspects of the entire ship. By using CATIA software and knowledge based engineering module, the 3D layout design of the engine room of a multi-purpose cargo ship was studied. Ship engine room classification rules were established to improve the efficiency of knowledge acquisition, equipment virtual area increase rules were established to control equipment spacing, and parameterized assembly were used to complete knowledge reasoning. Finally, the generated layout scheme was verified by experts through three rules of roll torque, interference inspection, and escape time. The results are in line with expectations, and the feasibility and effectiveness of knowledge based engineering in the 3D layout design of ship engine room are verified.

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    Analysis of Cross-Platform Coupling Vibration of Ultra-High-Speed Maglev Track Beam System
    CAI Wentao, WANG Chunjiang, TENG Nianguan, WEN Quan
    Journal of Shanghai Jiao Tong University    2021, 55 (10): 1228-1236.   DOI: 10.16183/j.cnki.jsjtu.2020.101
    Abstract544)   HTML14)    PDF(pc) (1581KB)(269)       Save

    Track beam is an important structural component in maglev transportation. The analysis of its structural performance is quite critical, especially for the coupled dynamic analysis under the action of high-speed moving train, which is directly related to the operation safety and stability of the train. The dynamic coupling of the 600 km/h ultra-high-speed maglev track beam was studied, the train model was based on 5 rigid bodies and 30 degrees of freedom system, and the spatial coupling analysis model of the maglev track beam was established by using the Timoshenko beam element model with shear effect considered. For the specific implementation of the coupling analysis in the cross platform framework, the multi-body dynamics software Simpack, the large-scale finite element software ANSYS and the visual simulation tool MATLAB/Simulink modeling method were used, and the PID controller was introduced to actively control the whole suspension control system. The whole coupling system was divided into the main vehicle master system, the controller subsystem, and the track beam-pier subsystem. Besides, a coupled vibration model of maglev vehicle-controller-track beam was established. Taking a simply supported bridge with a span of 24.768 m as an example, the vertical dynamic response of the following cars and track beams of ultra-high-speed maglev vehicle running was studied, and the dynamic performance of the control system was evaluated. In addition, the change law of multi-parameter dynamic response considering the influence of bridge pier parametric vibration is given, which will provide technical support for the construction of ultra-high-speed maglev projects in the future.

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    A Structural Reconstruction Method of Large Ship Based on Grey Theory
    WANG Zhikai, CHEN Jin, YAO Xiongliang, JIANG Zifei
    Journal of Shanghai Jiao Tong University    2021, 55 (11): 1429-1437.   DOI: 10.16183/j.cnki.jsjtu.2020.056
    Abstract461)   HTML10)    PDF(pc) (3978KB)(275)       Save

    Aimed at the reconstruction problem of foreign large-scale warships, the spacing and minimum plate thickness of some profiles of large-scale warships are obtained by adopting the grey theory method and taking the data in the design code of warships as samples. Based on the advantages of the grey theory in dealing with small data and uncertainties, the grey models of different captains and their corresponding profile parameters are built and compared with the data of foreign large ships. The results show that the method has a high accuracy in calculating structural parameters with a strong correlation with the total longitudinal strength. The reason for the deviation in calculating structural parameters with local strength as the main consideration factor lies in the fact that the captain parameters as the reference for modeling are highly correlated with the total longitudinal strength. The magnitude of the deviation by calculating the grey relational degree between the structural parameters and the captain is described, and the results obtained are of engineering application value.

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