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Research on dynamic response prediction of semi-submersible wind turbine platform in real sea test model based on machine learning

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APPLIED OCEAN RESEARCH 2024年 142卷

作者： Jiang, Hairui Wang, Hehe Vaz, Murilo A. Bai, Xinglan Zhejiang Ocean Univ Sch Naval Architecture & Maritime Zhoushan 316022 Peoples R China Key Lab Offshore Engn Technol Zhejiang Prov Zhoushan 316022 Peoples R China Fed Univ Rio Janeiro Ocean Engn Program Rio De Janeiro Brazil

The motion response of floating offshore wind turbine (FOWT) platform is closely related to its safety, and model test is the most direct method to fully study its dynamic characteristic behavior. In this paper the dynamic response of intermediate-scale physical semi-submersible FOWT model test under real sea environmental loads is studied and compared with the numerical model dynamic response, demonstrating that some limitations of small-scale physical model tests can be overcome, such as the catenary effect of mooring lines. It is found that the nonlinear dynamic characteristics of the physical model under actual marine environmental loads can be captured by the numerical model, which can improve the fidelity of model test data for semi-submersible FOWT structures in the existing literature. The dynamic response database of semi-submersible FOWT under complex wind, wave and current loads was established by using a numerical model with high accuracy, and was used in the prediction research of different machine learning algorithm models such as Genetic Algorithm optimization Back Propagation neural network (GA-BP), Support Vector Machine (SVM) and Gaussian Process (GP). The research shows that the relationship between the environmental load and the dynamic response of FOWT can be established by using the machine learning model, in which the number of samples has a significant impact on the prediction of the mooring line tension, and the research on the three algorithm models shows that GP performs significantly better than GA-BP and SVM in predicting the mean value of surge, pitch and mooring line force. For the dynamic response prediction of mooring line tension, GP model can get better results. In the future, this method will become an important method to predict and monitor the dynamic response of FOWT.

关键词： Floating offshore wind turbines Machine learning Dynamic response prediction Intermediate-scale model test Numerical simulation

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Acquisition of Key Vacuum-Assisted Resin Transfer Molding Parameters through Reverse Scanning for Application in the Manufacturing of Large Fiber-Reinforced-Plastic Products

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INTERNATIONAL JOURNAL OF POLYMER SCIENCE 2023年第12023期2023卷 7927196-7927196页

作者： Luo, Guang-Min Chen, Kai-Lin Hsu, Chen-Ting Natl Kaohsiung Univ Sci & Technol Dept Naval Architecture & Ocean Engn Kaohsiung Taiwan Natl Kaohsiung Univ Sci & Technol Ph D Program Maritime Sci & Technol Kaohsiung Taiwan

Software-based mold flow analysis is often performed to confirm optimized resin pipe arrangements. In this study, the GeoDict software and reverse scanning were employed to develop a method for performing rapid porosity and permeability estimation. A comparison of the results from one-dimensional resin flow and Easyperm tests revealed a 10% variation in the porosity and permeability parameters obtained through the proposed rapid estimation method. In addition, the obtained parameters were substituted into a Moldex3D model to simulate the resin flow on the personal watercraft hull during vacuum-assisted resin transfer molding (VARTM). A comparison of simulation results and hull infusion results revealed that the integration of the proposed rapid estimation method with Moldex3D allowed for the accurate simulation of the resin flow in large fiber-reinforced-plastic (FRP) products (variation <8%). The proposed method can be applied to large wind turbine FRP parts and large FRP yacht components to increase process planning efficiency and product stability.

关键词： Resin transfer molding

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Environmental sustainability criteria in the multi-oriented shipbuilding industry in Indonesia

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Australian Journal of Maritime and Ocean Affairs 2024年第4期16卷 410-430页

作者： Azhar, Ali Harahab, Nuddin Putra, Fadilla Kurniawan, Andi Department of Naval Architecture and Ship Building Faculty of Engineering and Marine Science Hang Tuah University Surabaya Indonesia Postgraduate Environmental Science Doctorate Program Brawijaya University Malang Indonesia

Preliminary studies have highlighted the potential of Indonesia's geographical, suprastructural, and infrastructural conditions to develop a strong shipbuilding industry, which is crucial for the success of the world maritime axis program and sea toll. However, despite high expectations, the industry faces challenges that threaten business sustainability, leading to bankruptcies. To assess business sustainability, it is essential to establish criteria and sub-criteria, which previous studies have overlooked, focusing only on technical and economic factors. Therefore, this research generally aims to develop and analyze environmentally friendly sustainable criteria in the multi-oriented shipyard industry so that it develops in accordance with the vision, mission, goals and strategies. The criteria development process involves identifying and reviewing relevant articles, classifying and refining the criteria, conducting expert validity testing, Pearson Product Moment validity testing, and reliability testing using the Alpha (Cronbach) method. The expert validity testing indicates that ‘people' received the highest average score of 4.67 among the criteria, and ‘infrastructure' scored the highest in the sub-criteria, with a score of 4.75. The validity testing with the Pearson Product Moment method demonstrates that the criteria and sub-criteria are valid and the reliability of 32 sub-criteria indicating their influence on promoting multi-oriented and environmentally sustainable shipbuilding industries. © 2023 Informa UK Limited, trading as Taylor & Francis Group.

关键词： Indonesia Shipyard Industry SPSS software sustainability

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Meshless generalized finite difference method with a domain-selection method for solving degenerate boundary problems

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Engineering Analysis with Boundary Elements 2023年第1期152卷 185-193页

作者： Huang, Ji Lyu, Hong-Guan Fan, Chia-Ming Chen, Jiahn-Horng Naval Architecture and Shipping College Guangdong Ocean University Zhanjiang524088 China School of Ocean Engineering and Technology Sun Yat-sen University Zhuhai519082 China Doctoral Degree Program in Ocean Engineering Technology National Taiwan Ocean University Keelung20224 Taiwan Department of Harbor and River Engineering National Taiwan Ocean University Keelung20224 Taiwan Shih Yen-Ping Center for Underwater Technology National Taiwan Ocean University Keelung20224 Taiwan National Academy of Marine Research Kaohsiung80661 Taiwan

This paper is dedicated to presenting a combined Generalized Finite Difference Method (GFDM) and Domain-Selection Method (DSM) approach for solving degenerate boundary problems which are usually encountered in engineering simulations. Compared with traditional Domain-Decomposition Method (DDM), the most critical advantage of the present GFDM-DSM is that it is entirely free from matching continuous boundary conditions for different parts of the fluid domain of interest, which is sometimes hard to perform for specific situations. Instead, the only prerequisite of the present GFDM-DSM is to identify which sub-domain each computational node belongs to, and then a linear algebraic system can be assembled according to the pattern of domain-selection. Four benchmarks are performed to validate the convergence and accuracy of the present GFDM-DSM. It is shown that the present GFDM-DSM holds satisfactory accuracy for solving degenerate boundary problems. In particular, the present DSM is a flexible strategy since it can be also combined with other localized domain-type meshless methods in practical applications. © 2023 Elsevier Ltd

关键词： Domain decomposition methods

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Wave interaction with multiple wavy porous barriers using dual boundary element method

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ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS 2021年 122卷 176-189页

作者： Vijay, K. G. Nishad, Chandra Shekhar Neelamani, S. Sahoo, T. IIT Kharagpur Dept Ocean Engn & Naval Architecture Kharagpur 721302 W Bengal India Pandit Deendayal Petr Univ Sch Technol Dept Math Gandhinagar 382007 Gujrat India Kuwait Inst Sci Res Environm & Life Sci Res Ctr Coastal Management Program POB 24885 Safat 13109 Kuwait

The gravity wave interaction with horizontally staggered multiple thin wavy porous barriers is analyzed under the assumption of potential flow theory. The dual boundary element method (DBEM) is used to solve the boundary value problem. The accuracy and reliability of the DBEM solutions are ascertained by comparing with known results in the literature and with an independently developed multi-domain boundary element method (MBEM) code. The study is focused on the scattering coefficients and vertical forces on an array of wavy barriers. The numerical results demonstrate that wave transmission by a horizontally staggered porous barrier is much better compared to a single horizontal plate. It is recommended to use plate porosity of 0.05 to 0.20, if transmission coefficient of less than 0.50 is needed, especially for relative water depth k(0)h > 2. With an increase in the number of ripples and ripple amplitude on the porous plates, it is possible to further reduce wave transmission by 5% to 10%. Also, an increase in the inclination of the plate from 0 to 10 degrees can reduce the wave transmission and increases the wave reflection to 5% to 10%. Further, a reduction of about 10% to 30% in the vertical force on the wavy plate is possible for k(0)h >= 1 with an increase in the relative ripple amplitude, the number of ripples and increased plate rotation. This essentially will help in the reduction of pile penetration length into the sea bed soil. The results of the present study can be used for the optimal design of wavy plate as a wave barrier for offshore and coastal engineering applications.

关键词： Submerged thin horizontal wavy porous barrier Darcy's law Quadratic pressure drop Scattering coefficients Dual boundary element method

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Component Criticality Rating of a Subsea Manifold using FMECA 32nd

Component Criticality Rating of a Subsea Manifold using FMEC...

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32nd European Safety and Reliability Conference, ESREL 2022

作者： Nicolau, Andressa S. Martins, Maximiano C. Paulo, Fernando F. Melo, Frutuoso E. Schleder, Adriana M. Martins, Marcelo R. De Barros, Leonardo O. Orlowski, Rene Thiago C. COPPE Graduate Program of Nuclear Engineering Federal University of Rio de Janeiro Rio de Janeiro Brazil LabRisco Analysis Evaluation and Risk Management Laboratory Naval Architecture and Ocean Engineering Department University of Sao Paulo Sao Paulo Brazil CENPES Research and Development Center of Petrobras Petrobras Brazil

ISBN: (纸本)9789811851834

Subsea manifold is a metallic structure fixed to the seabed, in which valves and accessory equipment are installed that make it possible to couple Wet Christmas Trees and other production systems (such as Pipeline End Manifold, Pipeline End Termination and risers);it is required during the completion and production of oil and gas wells. The failure of the subsea manifold can cause serious damage to the environment and human health, as well as stop production causing the loss of large foreign exchange, so ensuring its integrity is extremely important for the sector. In this article a Failure Mode, Effects and Criticality Analysis is presented for the criticality classification of the components of a typical subsea manifold cluster, Pipeline end manifold and Pipeline end termination. The final effect of equipment failure in the manifold was evaluated as a function of production interruption, production reduction, rupture, environmental pollution, plugging, leakage and structural collapse. Different means of detection were considered. The results of this study provide information about the weakness of the subsea manifold equipment. It is expected that this paper can contribute to future analysis of similar equipment and means to contribute to future work involving risk analysis, and inspection maintenance plan. © 2022 ESREL2022 Organizers. Published by Research Publishing, Singapore.

关键词： Christmas trees (wellheads)

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Point Set Voting for Partial Point Cloud Analysis

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IEEE ROBOTICS AND AUTOMATION LETTERS 2021年第2期6卷 596-603页

作者： Zhang, Junming Chen, Weijia Wang, Yuping Vasudevan, Ram Johnson-Roberson, Matthew Univ Michigan Dept Elect Engn & Comp Sci Ann Arbor MI 48109 USA Univ Michigan Robot Program Ann Arbor MI 48109 USA Univ Michigan Dept Mech Engn Ann Arbor MI 48109 USA Univ Michigan Dept Naval Architecture & Marine Engn Ann Arbor MI 48109 USA

The continual improvement of 3D sensors has driven the development of algorithms to perform point cloud analysis. In fact, techniques for point cloud classification and segmentation have in recent years achieved incredible performance driven in part by leveraging large synthetic datasets. Unfortunately these same state-of-the-art approaches perform poorly when applied to incomplete point clouds. This limitation of existing algorithms is particularly concerning since point clouds generated by 3D sensors in the real world are usually incomplete due to perspective view or occlusion by other objects. This paper proposes a general model for partial point clouds analysis wherein the latent feature encoding a complete point cloud is inferred by applying a point set voting strategy. In particular, each local point set constructs a vote that corresponds to a distribution in the latent space, and the optimal latent feature is the one with the highest probability. This approach ensures that any subsequent point cloud analysis is robust to partial observation while simultaneously guaranteeing that the proposed model is able to output multiple possible results. This paper illustrates that this proposed method achieves the state-of-the-art performance on shape classification, part segmentation and point cloud completion.

关键词： Three-dimensional displays Training Task analysis Solid modeling Analytical models Shape Decoding Deep learning methods

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Flexible cylinder flow-induced vibration

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PHYSICS OF FLUIDS 2022年第1期34卷 1-22页

作者： Ma, Leixin Lin, Ke Fan, Dixia Wang, Jiasong Triantafyllou, Michael S. MIT Dept Mech Engn Cambridge MA 02139 USA Shanghai Jiao Tong Univ Sch Naval Architecture Ocean & Civil Engn Dept Engn Mech Shanghai 200240 Peoples R China Queens Univ Dept Mech & Mat Engn Kingston ON K7M 3N9 Canada Westlake Univ Sch Engn Hangzhou 310024 Zhejiang Peoples R China MIT Sea Grant Coll Program Cambridge MA 02139 USA

In this paper, we conducted a selective review on the recent progress in physics insight and modeling of flexible cylinder flow-induced vibrations (FIVs). FIVs of circular cylinders include vortex-induced vibrations (VIVs) and wake-induced vibrations (WIVs), and they have been the center of the fluid-structure interaction (FSI) research in the past several decades due to the rich physics and the engineering significance. First, we summarized the new understanding of the structural response, hydrodynamics, and the impact of key structural properties for both the isolated and multiple circular cylinders. The complex FSI phenomena observed in experiments and numerical simulations are explained carefully via the analysis of the vortical wake topology. Following up with several critical future questions to address, we discussed the advancement of the artificial intelligent and machine learning (AI/ML) techniques in improving both the understanding and modeling of flexible cylinder FIVs. Though in the early stages, several AL/ML techniques have shown success, including auto-identification of key VIV features, physics-informed neural network in solving inverse problems, Gaussian process regression for automatic and adaptive VIV experiments, and multi-fidelity modeling in improving the prediction accuracy and quantifying the prediction uncertainties. These preliminary yet promising results have demonstrated both the opportunities and challenges for understanding and modeling of flexible cylinder FIVs in today's big data era.

关键词： Circular cylinders

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Estimation of ship operational efficiency from AIS data using big data technology

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INTERNATIONAL JOURNAL OF naval architecture AND OCEAN ENGINEERING 2020年 12卷 440-454页

作者： Kim, Seong-Hoon Roh, Myung-Il Oh, Min-Jae Park, Sung-Woo Kim, In-Il Seoul Natl Univ Dept Naval Architecture & Ocean Engn Seoul South Korea Seoul Natl Univ Res Inst Marine Syst Engn Dept Naval Architecture & Ocean Engn 1 Gwanak Ro Seoul 08826 South Korea Univ Ulsan Sch Naval Architecture & Ocean Engn Ulsan South Korea Seoul Natl Univ Interdisciplinary Program Offshore Plant Engn Seoul South Korea Daewoo Shipbldg & Marine Engn Co Ltd Smartship Dept R&D Inst Seoul South Korea

To prevent pollution from ships, the Energy Efficiency Design Index (EEDI) is a mandatory guideline for all new ships. The Ship Energy Efficiency Management Plan (SEEMP) has also been applied by MARPOL to all existing ships. SEEMP provides the Energy Efficiency Operational Indicator (EEOI) for monitoring the operational efficiency of a ship. By monitoring the EEOI, the shipowner or operator can establish strategic plans, such as routing, hull cleaning, decommissioning, new building, etc. The key parameter in calculating EEOI is Fuel Oil Consumption (FOC). It can be measured on board while a ship is operating. This means that only the shipowner or operator can calculate the EEOI of their own ships. If the EEOI can be calculated without the actual FOC, however, then the other stakeholders, such as the shipbuilding company and Class, or others who don't have the measured FOC, can check how efficiently their ships are operating compared to other ships. In this study, we propose a method to estimate the EEOI without requiring the actual FOC. The Automatic Identification System (AIS) data, ship static data, and environment data that can be publicly obtained are used to calculate the EEOI. Since the public data are of large capacity, big data technologies, specifically Hadoop and Spark, are used. We verify the proposed method using actual data, and the result shows that the proposed method can estimate EEOI from public data without actual FOC. (C) 2020 Society of naval Architects of Korea. Production and hosting by Elsevier B.V.

关键词： Ship operational efficiency Energy Efficiency Operational Indicator (EEOI) Fuel Oil Consumption (FOC) Automatic Identification System (AIS) Big data

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Applying reverse engineering principles on analysis of failures occurred in ship production

Applying reverse engineering principles on analysis of failu...

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SNAME Maritime Convention 2021, SMC 2021

作者： Karahan, Canberk Helvacioglu, Sebnem Helvacioglu, Ismail H. Türk Loydu Conformity Assessment Services Co. Istanbul Turkey Marine Engineering Program Istanbul Turkey Piri Reis University Faculty of Engineering Department of Naval Architecture and Marine Engineering Istanbul Turkey

In the current work, a new error evaluation methodology is introduced based on error analysis in ship production with reverse engineering data. The aim is to determine the errors and prevent or reduce the occurrence in other projects. First step is to compose a database of the errors;then, group the similar errors and calculate the Error Priority Number (EPN) by the evaluation of the predetermined criteria. The radar diagrams, which are suitable for representing a number of parameters having the same variables, were used to present the error groups in a simple way. The error groups were created on the diagram with the scores taken from the specific criteria. With the aid of the radar diagram, valuable information is given by presenting similarities and dissimilarities of these errors with other error groups. After examining the radar diagrams and evaluating the results, the cause and effect diagrams were prepared for these error groups from the field experts. Thus, the methodology should be customized for the shipyard to ensure maximum efficiency. © 2021 Society of naval Architects and Marine Engineers (SNAME)

关键词： Shipyards

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