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预测规则波浪中船舶运动和载荷的频域三维计算机程序

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哈尔滨工程大学学报（英文版） 2024年第1期23卷 64-73页

作者： Arash Abbasnia Serge Sutulo C.Guedes Soares Centre for Marine Technology and Engineering(centec) Instituto Superior TécnicoUniversidade de Lisboa1049-001 LisboaPortugal

The development of an in-house computer program for determining the motions and loads of advancing ships through sea waves in the frequency domain,is described in this *** code is based on the potential flow formulation and originates from a double-body code enhanced with the regular part of the velocity potential computed using the pulsing source Green *** code is fully developed in C++language with extensive use of the object-oriented *** code is capable of estimating the excitation and inertial radiation loads or arbitrary incoming wave frequencies and incidence *** hydrodynamic responses such as hydrodynamic coefficients,ship motions,the vertical shear force and the vertical bending moment are estimated.A benchmark container ship and an LNG carrier are selected for testing and validating the computer *** obtained results are compared with the available experimental data which demonstrate the acceptable compliance for the zero speed whereas there are some discrepancies over the range of frequencies for the advancing ship in different heading angles.

关键词： Frequency domain Advancing ships Diffraction theory Pulsing green’s function Boundary integral equation

RepDNet:A re-parameterization despeckling network for autonomous underwater side-scan sonar imaging with prior-knowledge customized convolution

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Defence Technology（防务技术） 2024年第5期35卷 259-274页

作者： Zhuoyi Li Zhisen Wang Deshan Chen Tsz Leung Yip Angelo P.Teixeira Department of Logistics and Maritime Studies The Hong Kong Polytechnic UniversityChina State Key Laboratory of Maritime Technology and Safety Wuhan University of TechnologyChina School of Transportation and Logistics Engineering Wuhan University of TechnologyChina National Engineering Research Center for Water Transport Safety Wuhan University of TechnologyChina Centre for Marine Technology and Ocean Engineering(centec) Instituto Superior TecnicoUniversidade de LisboaPortugal

Side-scan sonar(SSS)is now a prevalent instrument for large-scale seafloor topography measurements,deployable on an autonomous underwater vehicle(AUV)to execute fully automated underwater acoustic scanning imaging along a predetermined ***,SSS images often suffer from speckle noise caused by mutual interference between echoes,and limited AUV computational resources further hinder noise *** approaches for SSS image processing and speckle noise reduction rely heavily on complex network structures and fail to combine the benefits of deep learning and domain *** address the problem,Rep DNet,a novel and effective despeckling convolutional neural network is *** DNet introduces two re-parameterized blocks:the Pixel Smoothing Block(PSB)and Edge Enhancement Block(EEB),preserving edge information while attenuating speckle *** training,PSB and EEB manifest as double-layered multi-branch structures,integrating first-order and secondorder derivatives and smoothing *** inference,the branches are re-parameterized into a 3×3 convolution,enabling efficient inference without sacrificing *** DNet comprises three computational operations:3×3 convolution,element-wise summation and Rectified Linear Unit *** on benchmark datasets,a real SSS dataset and Data collected at Lake Mulan aestablish Rep DNet as a well-balanced network,meeting the AUV computational constraints in terms of performance and latency.

关键词： Side-scan sonar Sonar image despeckling Domain knowledge Re-parameterization

采用解析和数值方法分析浮动式矩形浮箱的波浪诱导载荷研究

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哈尔滨工程大学学报（英文版） 2024年第1期23卷 113-126页

作者： Sarat Chandra Mohapatra Iuri Baldaconi da Silva Bispo Yuchan Guo C.Guedes Soares Center for Marine Technology and Ocean Engineering(centec) Instituto Superior TécnicoUniversidade de LisboaLisboa 1049-001Portugal

A three-dimensional mathematical hydrodynamic model associated with surface wave radiation by a floating rectangular box-type structure due to heave,sway,and roll motions in finite water depth is investigated based on small amplitude water wave theory and linear structural *** analytical expressions for the radiation potentials,wave forces,and hydrodynamic coefficients are presented based on matched eigenfunction expansion method(MEFEM).The correctness of the analytical results of wave forces is compared with the construction of a numerical model using the open-source boundary element method code *** addition,the present result is compared with the existing published experimental results available in the *** effects of the different design parameters on the floating box-type rectangular structure are studied by analyzing the vertical wave force,horizontal wave force,torque,added mass,and damping coefficients due to the heave,sway,and roll motions,and the comparison analysis between the forces is also analyzed in ***,the effect of reflection and transmission coefficients by varying the structural width and drafts are analyzed.

关键词： Mathematical model MEFEM Box-type structure BEM code NEMOH Wave forces

Modified Joint Distribution of Wave Heights and Periods

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China Ocean Engineering 2016年第3期30卷 359-374页

作者： H.D.Zhang C.Guedes Soares Centre for Marine Technology and Ocean Engineering (centec) Instituto Superior Técnico Universidade de Lisboa

The modified versions of the linear theoretical model of Longuet-Higgins （1983） are derived in this work and also compared with the laboratory experiments carried out in MAR1NTEK. The main feature of modifications is to replace the mean frequency in the formulation with the peak frequency of the wave spectrum. These two alternative forms of joint distributions are checked in three typical random sea states characterized by the initial wave steepness. In order to further explore the properties ＆these models, the associated marginal distributions of wave heights and wave periods are also researched with the observed statistics and some encouraging results are obtained.

关键词： Longuet-Higgins joint distribution mixed sea state nonlinear wave series wave height wave period

Spudcan Penetration Simulation Using the Coupled Eulerian-Lagrangian Method with Thermo-Mechanical Coupled Analysis

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Journal of Ocean University of China 2019年第2期18卷 317-327页

作者： YIN Qilin DONG Sheng JIANG Fengyuan GUEDES SOARES Carlos College of Engineering Ocean University of China Centre for Marine Technology and Ocean Engineering (centec) Instituto Superior Técnico

A novel modeling technique based on the coupled Eulerian-Lagrangian(CEL) method is provided to solve the geotechnical problems with large deformations. The technique is intended to solve the update problem of soil mechanical properties during spudcan penetration in normally consolidated clay soil. In the CEL model, the normal method of assigning an increasing shear strength profile with depth(NA) is defective due to its Eulerian framework. In this paper, a new technique is proposed to update soil material properties by introducing thermo-mechanical coupled analysis(TMCA) to the CEL models. During establishment of the CEL models, the optimal penetration velocity and minimum mesh size are determined through parametric studies. Reasonability and accuracy are then verified through comparison of the preliminary results with the soil flow configuration and penetration resistance(Fv) of a centrifuge test, and the results of the proposed method are compared with those of the remeshing and interpolation technique with small strain(RITSS) method. To achieve a CEL model with satisfactory accuracy, the NA and TMCA methods implemented in the CEL models and the RITSS method are first adopted in weightless soil. Comparison of the findings with those obtained in previous studies shows that the TMCA method can update material properties and predict Fv. The TMCA method is then applied to soils with self-weight and different shear strength profiles. Results show that the proposed method is capable of accurately modeling the large deformation problem of spudcan penetration in non-homogeneous clay.

关键词： thermo-mechanical coupled analysis non-homogeneous clay spudcan penetration CEL RITSS

Interaction between surface gravity wave and submerged horizontal flexible structures

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Journal of Hydrodynamics 2018年第3期30卷 481-498页

作者： Sarat Chandra Mohapatra Trilochan Sahoo C.Guedes Soares Centre for Marine Technology and Ocean Engineering (centec) Instituto Superior TécnicoUniversidade de Lisboa Department of Ocean Engineering and Naval Architecture Indian Institute of Technology

Interactions between surface gravity wave and submerged horizontal flexible structures are studied under the assumption of small amplitude water wave theory and structural response. The generalized dispersion relation associated with surface gravity wave interaction with submerged horizontal flexible plate is analyzed to understand the characteristics of the two propagating modes due to the presence of the free surface and submerged horizontal plate. The phase and group velocities are studied in order to analyze the effect of submerged flexible plate on gravity wave motion. The expansion formulae based on Green’s function technique and eigenfunction expansion method using Fourier transform with appropriate orthogonal mode-coupling relation associated with surface gravity wavemaker problems are derived and compared in both the cases of water of finite and infinite depths. The usefulness of the expansion formulae is demonstrated by deriving the solution for surface gravity wave interaction with submerged articulated flexible plate in water of finite depth. Several numerical results on reflection and transmission coefficients related to submerged flexible plate are presented in order to understand the effect of submerged flexible structure on surface wave motion in different cases.

关键词： Submerged flexible structures Green’s function expansion formulae articulated submerged plate reflection and transmission coefficients

Review of Ship Slamming Loads and Responses

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Journal of Marine Science and Application 2017年第4期16卷 427-445页

作者： Shan Wang C.Guedes Soares Centre for Marine Technology and Ocean Engineering(centec) Instituto Superior TécnicoUniversidade de LisboaLisboa 1049-001Portugal

The paper presents an overview of studies of slamming on ship structures. This work focuses on the hull slamming, which is one of the most important types of slamming problems to be considered in the ship design process and the assessment of the ship safety. There are three main research aspects related to the hull slamming phenomenon, a) where and how often a slamming event occurs, b) slamming load prediction and c) structural response due to slamming loads. The approaches used in each aspect are reviewed and commented, together with the presentation of some typical results. The methodology, which combines the seakeeping analysis and slamming load prediction, is discussed for the global analysis of the hull slamming of a ship in waves. Some physical phenomena during the slamming event are discussed also. Recommendations for the future research and developments are made.

关键词： review slamming probability ship slamming hydroelasticity

System Reliability Analysis of an Offshore Jacket Platform

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Journal of Ocean University of China 2020年第1期19卷 47-59页

作者： ZHAO Yuliang DONG Sheng JIANG Fengyuan GUEDES SOARES Carlos College of Engineering Ocean University of ChinaQingdao 266100China Centre for Marine Technology and Ocean Engineering(centec Instituto Superior TécnicoLisboa 1049-001Portugal

This study investigates strategies for solving the system reliability of large three-dimensional jacket *** structural systems normally fail as a result of a series of different components *** failure characteristics are investigated under various environmental conditions and direction ***β-unzipping technique is adopted to determine critical failure components,and the entire system is simplified as a series-parallel system to approximately evaluate the structural system ***,this approach needs excessive computational effort for searching failure components and failure *** on a trained artificial neural network(ANN),which can be used to approximate the implicit limit-state function of a complicated structure,a new alternative procedure is proposed to improve the efficiency of the system reliability analysis *** failure probability is calculated through Monte Carlo simulation(MCS)with Latin hypercube sampling(LHS).The features and applicability of the above procedure are discussed and compared using an example jacket platform located in Chengdao Oilfield,Bohai Sea,*** study provides a reference for the evaluation of the system reliability of jacket structures.

关键词： system reliability jacket platform β-unzipping technique artificial neural network latin hypercube sampling response surface

Hydroelastic Analysis of a Rectangular Plate Subjected to Slamming Loads

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Journal of Marine Science and Application 2017年第4期16卷 405-416页

作者： Shan Wang C.Guedes Soares Centre for Marine Technology and Ocean Engineering(centec) Instituto Superior TécnicoUniversidade de LisboaLisboa 1049-001Portugal

A hydroelastic analysis of a rectangular plate subjected to slamming loads is presented. An analytical model based on Wagner theory is used for calculations of transient slamming load on the ship plate. A thin isotropic plate theory is considered for determining the vibration of a rectangular plate excited by an external slamming force. The forced vibration of the plate is calculated by the modal expansion method. Analytical results of the transient response of a rectangular plate induced by slamming loads are compared with numerical calculations from finite element method. The theoretical slamming pressure based on Wagner model is applied on the finite element model of a plate. Good agreement is obtained between the analytical and numerical results for the structural deflection of a rectangular plate due to slamming pressure. The effects of plate dimension and wave profile on the structural vibration are discussed as well. The results show that a low impact velocity and a small wetted radial length of wave yield negligible effects of hydroelasticity.

关键词： slamming load hydroelastic analysis vibration of plates modal expansion method finite element method