Applied Ocean Research最新文献

英文中文

Real-time synthesis of the dynamic responses of floating bodies to waves for maritime simulators

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104393

Luca Donatini , Jeroen Verwilligen , Guillaume Delefortrie , Marc Vantorre , Evert Lataire

A new implementation of the Fourier approach to synthesize spectral waves in real-time was recently published by the authors, based on an efficient GPU implementation and on a very flexible definition of the wave inputs. This paper presents an extension of the method to deal with the time-domain synthesis of frequency-domain responses of floating bodies, which can be calculated offline with a linear seakeeping solver. The frequency-domain responses are mapped from frequency/direction space to wavenumber space in order to match the same wave components used by the synthesis of the ocean surface, and they are transformed into time-domain responses by means of Inverse Discrete Fourier Transforms. Given the large number of elementary wave components required for a realistic visualization of the ocean surface, the synthesis of dynamic responses becomes computationally expensive and was implemented on GPUs relying on parallel reduction algorithms to speed up the summations. The performance of the GPU implementation was investigated, showing how the present method can synthesize multiple dynamic responses in real-time even when dealing with many elementary wave components. The physical accuracy of the technique proposed in the paper was assessed by simulating a virtual wave measurement buoy: the frequency-domain responses of the buoy were calculated with a linear seakeeping solver and then synthesized according to the proposed method. Then, the timeseries of buoy motions were used to reconstruct directional wave spectra, which proved to be in very good agreement with the wave spectra provided as inputs for the simulations.

{"title":"Real-time synthesis of the dynamic responses of floating bodies to waves for maritime simulators","authors":"Luca Donatini , Jeroen Verwilligen , Guillaume Delefortrie , Marc Vantorre , Evert Lataire","doi":"10.1016/j.apor.2024.104393","DOIUrl":"10.1016/j.apor.2024.104393","url":null,"abstract":"<div><div>A new implementation of the Fourier approach to synthesize spectral waves in real-time was recently published by the authors, based on an efficient GPU implementation and on a very flexible definition of the wave inputs. This paper presents an extension of the method to deal with the time-domain synthesis of frequency-domain responses of floating bodies, which can be calculated offline with a linear seakeeping solver. The frequency-domain responses are mapped from frequency/direction space to wavenumber space in order to match the same wave components used by the synthesis of the ocean surface, and they are transformed into time-domain responses by means of Inverse Discrete Fourier Transforms. Given the large number of elementary wave components required for a realistic visualization of the ocean surface, the synthesis of dynamic responses becomes computationally expensive and was implemented on GPUs relying on parallel reduction algorithms to speed up the summations. The performance of the GPU implementation was investigated, showing how the present method can synthesize multiple dynamic responses in real-time even when dealing with many elementary wave components. The physical accuracy of the technique proposed in the paper was assessed by simulating a virtual wave measurement buoy: the frequency-domain responses of the buoy were calculated with a linear seakeeping solver and then synthesized according to the proposed method. Then, the timeseries of buoy motions were used to reconstruct directional wave spectra, which proved to be in very good agreement with the wave spectra provided as inputs for the simulations.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104393"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of current on the hydroelastic behaviour of floating flexible circular structure

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104387

P. Amouzadrad, S.C. Mohapatra, C. Guedes Soares

An analytical model of wave-current interaction with a moored floating circular structure has been developed using Timoshenko-Mindlin beam theory. The analytical solution is derived utilising the matched eigenfunction expansion method, combined with orthogonal relations and Bessel functions. The convergence study of the analytical solution for different current speeds on the deflection amplitude, bending moment, and shear forces is demonstrated. Further, the correctness of the current solution is validated against existing published numerical results and experimental datasets and multiple outcomes of vertical displacement, bending moment, shear force, reflection and transmission coefficients on the current speed, and various design and physical parameters are examined. It has been noted that the current speed influences the structural responses significantly, and the present analysis may help understand the design parameters needed to model a VLFS application for ocean space utilisation.

引用次数: 0

Linear stability and numerical analysis of gas hydrate dissociation in hydrate bearing sediments

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104394

Yan Zhang , Jiangong Wei , Xuhui Zhang , Wanlong Ren , Xiaobing Lu , Hongsheng Guo , Tianju Wang

The stability of gas hydrate (GH) dissociation is crucial for understanding and predicting various hazards triggered by GH dissociation, such as landslides and gas blowouts. This study employs linear stability analysis and numerical simulation approaches to investigate the dynamics of GH dissociation under depressurization and heating. An instability criterion is derived, emphasizing conditions where the environmental heat supply exceeds the heat absorption by GH. We analyze the spatial and temporal evolution of key parameters, such as pore pressure, GH volume fraction, temperature, and strength, across different dissociation zones within the sediment. It is observed that pore pressure and temperature increase rapidly over time in unstable conditions, resulting in GH dissociation completing in approximately 10 s and a sharp decrease in the strength of hydrate-bearing sediments (HBS). Our findings offer insights into the behavior of HBS during GH dissociation and elucidate the formation mechanism of potential hazards associated with GH dissociation.

{"title":"Linear stability and numerical analysis of gas hydrate dissociation in hydrate bearing sediments","authors":"Yan Zhang , Jiangong Wei , Xuhui Zhang , Wanlong Ren , Xiaobing Lu , Hongsheng Guo , Tianju Wang","doi":"10.1016/j.apor.2024.104394","DOIUrl":"10.1016/j.apor.2024.104394","url":null,"abstract":"<div><div>The stability of gas hydrate (GH) dissociation is crucial for understanding and predicting various hazards triggered by GH dissociation, such as landslides and gas blowouts. This study employs linear stability analysis and numerical simulation approaches to investigate the dynamics of GH dissociation under depressurization and heating. An instability criterion is derived, emphasizing conditions where the environmental heat supply exceeds the heat absorption by GH. We analyze the spatial and temporal evolution of key parameters, such as pore pressure, GH volume fraction, temperature, and strength, across different dissociation zones within the sediment. It is observed that pore pressure and temperature increase rapidly over time in unstable conditions, resulting in GH dissociation completing in approximately 10 s and a sharp decrease in the strength of hydrate-bearing sediments (HBS). Our findings offer insights into the behavior of HBS during GH dissociation and elucidate the formation mechanism of potential hazards associated with GH dissociation.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104394"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Greedy dynamic reward algorithm-based coverage path planning for unmanned sailboats in non-stationary wind environments

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104382

Jinkun Shen , Zhongben Zhu , Guiqiang Bai , Zhongchao Deng , Yifan Xue , Xiaojian Cao , Xiaokai Mu , Hongde Qin

Unmanned sailboats, powered by wind, are well-suited for long-term island patrols but face challenges in maneuverability due to wind constraints, limiting route flexibility. This study addresses the issue of coverage path planning by proposing a Greedy Dynamic Reward Algorithm that incorporates wind conditions and sailboat kinematic constraints. A sailboat movement model is developed using a velocity prediction program. With dynamic rewards assigned to map grids based on wind direction, trajectory, and obstacles, the sailboat selects the grid with the highest reward among the available options for its next move. In cases of deadlock, a Breadth-First Search algorithm identifies the nearest uncovered node, and an improved artificial potential field method is employed to navigate to that node. Key strategies, including occupying the relatively most upwind position and disabling movement directions based on the sailed path, effectively minimize overlap and enhance the trackability of the path. Simulation results demonstrate the algorithm's robustness and adaptability in both single-island and archipelago environments, even under changing wind conditions. Furthermore, the study discusses potential directions for algorithm optimization.

{"title":"Greedy dynamic reward algorithm-based coverage path planning for unmanned sailboats in non-stationary wind environments","authors":"Jinkun Shen , Zhongben Zhu , Guiqiang Bai , Zhongchao Deng , Yifan Xue , Xiaojian Cao , Xiaokai Mu , Hongde Qin","doi":"10.1016/j.apor.2024.104382","DOIUrl":"10.1016/j.apor.2024.104382","url":null,"abstract":"<div><div>Unmanned sailboats, powered by wind, are well-suited for long-term island patrols but face challenges in maneuverability due to wind constraints, limiting route flexibility. This study addresses the issue of coverage path planning by proposing a Greedy Dynamic Reward Algorithm that incorporates wind conditions and sailboat kinematic constraints. A sailboat movement model is developed using a velocity prediction program. With dynamic rewards assigned to map grids based on wind direction, trajectory, and obstacles, the sailboat selects the grid with the highest reward among the available options for its next move. In cases of deadlock, a Breadth-First Search algorithm identifies the nearest uncovered node, and an improved artificial potential field method is employed to navigate to that node. Key strategies, including occupying the relatively most upwind position and disabling movement directions based on the sailed path, effectively minimize overlap and enhance the trackability of the path. Simulation results demonstrate the algorithm's robustness and adaptability in both single-island and archipelago environments, even under changing wind conditions. Furthermore, the study discusses potential directions for algorithm optimization.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104382"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143167006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Beach nourishment with coarse sediments: An in-situ investigation on the issues of abrasion and chipping

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104409

Chiara Favaretto , Duccio Bertoni , Alessandro Pozzebon , Luca Martinelli , Giovanni Sarti , Piero Ruol

The use of coarse sediments for beach nourishment represents an alternative solution to structural interventions for the protection of coasts that are exposed to energetic waves. Predicting the mass loss of fill material due to abrasion and scouring is crucial for proper nourishment design, as it has implications for the littoral sediment budget and sediment stability under extreme wave conditions. The present study aims at characterising the typical abrasion and chipping of coarse sediments used for beach nourishments, providing insights into their correlation with the wave energy flux incident on the coast. Estimation of weight loss and roundness variability is obtained through RFID (Radio Frequency IDentification) sediment tracking technology, 3D scanning techniques, and Los Angeles tests. The 1 year and 7 months in-situ investigation was carried out at Marina di Pisa (Italy), an artificial beach where the size of supplied pebbles was significantly reduced after few months of typical wave climate, jeopardizing the sediment stability and the lifetime of the nourishment. The methodology could be applied to other beaches and lithologies to establish a database of weight loss useful for coastal managers and engineers.

{"title":"Beach nourishment with coarse sediments: An in-situ investigation on the issues of abrasion and chipping","authors":"Chiara Favaretto , Duccio Bertoni , Alessandro Pozzebon , Luca Martinelli , Giovanni Sarti , Piero Ruol","doi":"10.1016/j.apor.2024.104409","DOIUrl":"10.1016/j.apor.2024.104409","url":null,"abstract":"<div><div>The use of coarse sediments for beach nourishment represents an alternative solution to structural interventions for the protection of coasts that are exposed to energetic waves. Predicting the mass loss of fill material due to abrasion and scouring is crucial for proper nourishment design, as it has implications for the littoral sediment budget and sediment stability under extreme wave conditions. The present study aims at characterising the typical abrasion and chipping of coarse sediments used for beach nourishments, providing insights into their correlation with the wave energy flux incident on the coast. Estimation of weight loss and roundness variability is obtained through RFID (Radio Frequency IDentification) sediment tracking technology, 3D scanning techniques, and Los Angeles tests. The 1 year and 7 months in-situ investigation was carried out at Marina di Pisa (Italy), an artificial beach where the size of supplied pebbles was significantly reduced after few months of typical wave climate, jeopardizing the sediment stability and the lifetime of the nourishment. The methodology could be applied to other beaches and lithologies to establish a database of weight loss useful for coastal managers and engineers.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104409"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Temperature-dependency and boundary condition impacts on the multiscale vibrational behavior of laminated nested dual conical shell structure semi-AUV applications

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2025.104425

Moein A. Ghandehari, Amir R. Masoodi, Ehsan Seyedi Hosseininia

This investigation examines the vibrational behavior of a novel shell structure, nested dual conical shells (NDCSs), and a truncated conical shell (TCS) under varying thermal conditions. The conical shells are composed of two parts, matrix and reinforcement. Polymethyl methacrylate (PMMA) employed as the matrix and single-walled carbon nanotubes (SWCNTs) considered as reinforcement, with mechanical properties that are influenced by ambient temperature. Considering the rule of mixtures (RoM), the tantamount mechanical characteristics of these smart composite materials (SCM) are determined, leading to the development of a comprehensive mathematical model. The First-Order Shear Deformation Theory (FSDT) and Donnell's approach are applied to establish the relationship between forces and strains. Subsequently, Hamilton's principal is used to derive governing deferential equations (GDEs) of NDCSs and TCS. The GDEs are solved through a numerical approach, called Generalized Differential Quadrature Method (GDQM). This research incorporates the boundary conditions (BCs) through the implementation of arbitrary constraints, allowing for an in-depth examination of the relationship between boundary stiffness and the natural frequency parameters (NFP) of NDCSs. The findings reveal that the NFP depend considerably on the distribution and volume of nanofillers, as well as the orientation of nanofillers under different thermal conditions. Numerical analyses show that as the temperature increases, the NFP decreases. Additionally, the results highlight that the highest NFP occur at specific reinforcer orientations, such as 60°, 120°, 240°, and 300° for the first mode, while 90° and 270° yield peak values for higher modes. The analysis reveals unique vibrational phenomena specific to the NDCSs structure, including the significant role of middle tier springs' stiffness, which governs the NFP behavior within a specific stiffness range.

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引用次数: 0

Numerical investigation of cavitation induced noise and noise reduction mechanism for the leading-edge protuberances

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104361

Tianyang Hou , Xinran Liu , Zhixing Li , Yana Wang , Tairan Chen , Biao Huang

Cavitation leads to an increase in noise for high-speed ships, propellers, etc., which exacerbates ocean noise pollution. The objectives of this paper are to investigate the sound generation mechanism of cavitation noise and explore the noise reduction mechanism for the leading-edge protuberances. The large eddy simulation (LES) and the Zwart cavitation model were used to predict the unsteady cavitating flow around the National Advisory Committee for Aeronautics (NACA) 0012 baseline hydrofoil and the modified hydrofoil with the leading-edge protuberances. The load noise was predicted using the Ffowcs Williams–Hawkings (FW-H) acoustic simulation method from the flow field results, while the cavitation noise was calculated using the Sound radiation theory for spherical cavity. The noise reduction characteristics were analyzed in combination with the evolution characteristics of cavities and vortices. The leading-edge protuberances prevent the formation of large-scale shedding vortices, significantly reducing the pressure fluctuation amplitude on the suction surface of the hydrofoil. The flow instability and cavity collapse become the major sources of noise when cavitation occurs. Cavitation not only leads to an increase in radiated noise but also affects the characteristic frequency of noise. The modified hydrofoil effectively suppresses the formation and development of cavities, reducing cavitation instability. The modified hydrofoil can effectively reduce monophonic noise in low-frequency bands, resulting in a reduction of approximately 10.5 dB in peak monophonic noise. The high-frequency broadband noise between 300 and 500 Hz is reduced by approximately 7.58 dB. This research provides a reference for noise reduction optimization of hydraulic machinery.

{"title":"Numerical investigation of cavitation induced noise and noise reduction mechanism for the leading-edge protuberances","authors":"Tianyang Hou , Xinran Liu , Zhixing Li , Yana Wang , Tairan Chen , Biao Huang","doi":"10.1016/j.apor.2024.104361","DOIUrl":"10.1016/j.apor.2024.104361","url":null,"abstract":"<div><div>Cavitation leads to an increase in noise for high-speed ships, propellers, etc., which exacerbates ocean noise pollution. The objectives of this paper are to investigate the sound generation mechanism of cavitation noise and explore the noise reduction mechanism for the leading-edge protuberances. The large eddy simulation (LES) and the Zwart cavitation model were used to predict the unsteady cavitating flow around the National Advisory Committee for Aeronautics (NACA) 0012 baseline hydrofoil and the modified hydrofoil with the leading-edge protuberances. The load noise was predicted using the Ffowcs Williams–Hawkings (FW-H) acoustic simulation method from the flow field results, while the cavitation noise was calculated using the Sound radiation theory for spherical cavity. The noise reduction characteristics were analyzed in combination with the evolution characteristics of cavities and vortices. The leading-edge protuberances prevent the formation of large-scale shedding vortices, significantly reducing the pressure fluctuation amplitude on the suction surface of the hydrofoil. The flow instability and cavity collapse become the major sources of noise when cavitation occurs. Cavitation not only leads to an increase in radiated noise but also affects the characteristic frequency of noise. The modified hydrofoil effectively suppresses the formation and development of cavities, reducing cavitation instability. The modified hydrofoil can effectively reduce monophonic noise in low-frequency bands, resulting in a reduction of approximately 10.5 dB in peak monophonic noise. The high-frequency broadband noise between 300 and 500 Hz is reduced by approximately 7.58 dB. This research provides a reference for noise reduction optimization of hydraulic machinery.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104361"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of the inlet gas volume fraction on the structural dynamic characteristics of gas‒liquid multiphase pumps

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104347

Xin Wu, Guojun Zhu, Jianjun Feng, Xingqi Luo

The inlet gas volume fraction (IGVF) has a significant impact on the performance of the gas‒liquid multiphase pump. To explore the effects of different IGVFs on the performance of gas–liquid multiphase pump, it is taken as the research object and the deformation and stress of the impeller and pump shaft under pure water and different IGVFs are obtained. The results show that the maximum deformation of the impeller occurs at the blade trailing edge. The maximum deformation of the impeller under 20%, 30% IGVF is reduced by 9.97% and 16.79% compared to 10% IGVF, respectively. The maximum deformation of the pump shaft is decreased by 0.15% and 0.26%, respectively. The stress of the impeller at the connection between the blade trailing edge and the hub is the largest. The maximum stress of the impeller at 20% and 30% IGVF is reduced by 310 Pa and 600 Pa compared to 10% IGVF, respectively. The radial force and the axis trace are uniformly under pure water and are chaotic under different IGVFs. Under pure water condition, the maximum deformation and stress fluctuation on the impeller and shaft is smaller than that under different IGVFs. The amplitude of maximum deformation fluctuation on the impeller and shaft becomes smaller with the increasing IGVF.

{"title":"Effects of the inlet gas volume fraction on the structural dynamic characteristics of gas‒liquid multiphase pumps","authors":"Xin Wu, Guojun Zhu, Jianjun Feng, Xingqi Luo","doi":"10.1016/j.apor.2024.104347","DOIUrl":"10.1016/j.apor.2024.104347","url":null,"abstract":"<div><div>The inlet gas volume fraction (IGVF) has a significant impact on the performance of the gas‒liquid multiphase pump. To explore the effects of different IGVFs on the performance of gas–liquid multiphase pump, it is taken as the research object and the deformation and stress of the impeller and pump shaft under pure water and different IGVFs are obtained. The results show that the maximum deformation of the impeller occurs at the blade trailing edge. The maximum deformation of the impeller under 20%, 30% IGVF is reduced by 9.97% and 16.79% compared to 10% IGVF, respectively. The maximum deformation of the pump shaft is decreased by 0.15% and 0.26%, respectively. The stress of the impeller at the connection between the blade trailing edge and the hub is the largest. The maximum stress of the impeller at 20% and 30% IGVF is reduced by 310 Pa and 600 Pa compared to 10% IGVF, respectively. The radial force and the axis trace are uniformly under pure water and are chaotic under different IGVFs. Under pure water condition, the maximum deformation and stress fluctuation on the impeller and shaft is smaller than that under different IGVFs. The amplitude of maximum deformation fluctuation on the impeller and shaft becomes smaller with the increasing IGVF.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"154 ","pages":"Article 104347"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on stress prediction model of EH36 steel in polar environments: Optimization of basis functions using adaptive genetic algorithm and simulated annealing

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2024.104402

Hegang Ji, Jian Zhang, Shi Hua, Renwei Liu, Sanxia Shi

As global temperatures rise, the Arctic route—a vital maritime corridor connecting Asia, Europe, and North America—is increasingly becoming a focus of international shipping. However, the extreme low-temperature environment of the Arctic presents significant challenges to the mechanical properties of shipbuilding steel, especially in marine engineering and ship design. This study investigates the mechanical behavior of polar-grade EH36 shipbuilding steel across a temperature range from -40 °C to 20 °C and strain rates from 0.00037/s to 5000/s, introducing an innovative approach for accurately predicting stress under these conditions. Comprehensive experimental data were obtained through a combination of quasi-static, low strain rate tensile tests, and high strain rate Split Hopkinson Pressure Bar tests. A stress prediction model was developed by integrating adaptive genetic algorithms and simulated annealing to optimize basis functions, enabling precise predictions across a wide spectrum of temperatures and strain rates. Model validation results demonstrate that the prediction error remains within 6 % under moderate strain rates from 1/s to 200/s, highlighting the model's high accuracy and broad applicability. This model not only overcomes the limitations of traditional experimental and interpolation methods but also provides essential data for the design and material selection of polar icebreaking ships, offering an efficient tool for engineers in extreme environments. These findings contribute to enhancing the performance and safety of vessels operating in polar regions.

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引用次数: 0

Failure modes and inclined bearing capacity of a modified suction caisson in sand

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-01-01 DOI: 10.1016/j.apor.2025.104416

Yun Bai , Dayong Li

Experiments and simulations are undertaken on the bearing behavior of a modified suction caisson (MSC) in sand under inclined load. Results show that the MSC movement modes include forward rotation, backward rotation, translations mainly along the horizontal and vertical directions. When the MSC rotates forward, the earth pressure generated by the upper soil in front of the MSC plays an important part of the capacity. The lower passive earth pressure is crucial when the backward rotation occurs. When the MSC mainly moves horizontally, the soil in front of the MSC is entirely aroused. For the MSC mainly translates vertically, the passive suction is an important part of the bearing capacity. Moreover, the earth pressure induced by the soil in front of the external structure cannot be ignored when the MSC rotates forward and moves horizontally. In addition, the inclined loading rate shows a significant impact on the inclined bearing behavior. In the case of rotation occurring, both the earth pressure and passive suction display positive correlations with the loading rate. As loading rate increases, the increment of passive suction for forward rotation is greater than that for backward rotation, while the increment of earth pressure is greater for backward rotation.

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