Ocean Engineering最新文献_第4页

Compression capacity of simply supported corroded cylindrical curved plates 简单支撑的腐蚀圆柱形曲面板的压缩能力

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-14 DOI: 10.1016/j.oceaneng.2024.119628

Qian Yang , Zhongwei Zhao , Shuoran Li , Zhendong Zhang , Ni Zhang , Bingzhen Zhao

Cylindrical curved plates are widely used in structures such as aircraft skins and marine vessels. Corrosion significantly affects the structural stability of these curved plates. A finite element model was established to analyze the influence of corrosion on the post-buckling strength of curved plates. The reliability of the developed stochastic finite element model was preliminarily verified through comparison with theoretical calculations. Stochastic numerical analysis revealed the effects of parameters such as corrosion depth, corrosion location, and geometric dimensions on the stability and load-bearing capacity of the curved plates. The study found that the width (b)and height (a) had no effect on compressive load-bearing capacity, while mesh size, curvature radius (R), and diameter-to-thickness ratio (b/t) had significant impacts. The impact of corrosion depth (t_c/t) was especially significant. This paper first proposed a theoretical formula to predict the reduction factor (η) for the compressive load-bearing capacity of uniformly corroded curved plates and then derived a formula for randomly corroded plates by modifying the equation for uniformly corroded plates. Finally, the study analyzed corrosion effects at different locations, revealing that the central region of the curved plate is the most sensitive to corrosion.

圆柱形曲面板广泛应用于飞机蒙皮和船舶等结构中。腐蚀会严重影响这些曲面板的结构稳定性。为分析腐蚀对曲面板屈曲后强度的影响，建立了一个有限元模型。通过与理论计算的比较，初步验证了所建立的随机有限元模型的可靠性。随机数值分析揭示了腐蚀深度、腐蚀位置和几何尺寸等参数对曲面板稳定性和承载能力的影响。研究发现，宽度（b）和高度（a）对抗压承载能力没有影响，而网格尺寸、曲率半径（R）和直径与厚度比（b/t）则有显著影响。腐蚀深度 (tc/t) 的影响尤为显著。本文首先提出了一个理论公式来预测均匀腐蚀曲面板抗压承载力的降低系数 (η)，然后通过修改均匀腐蚀板的公式得出了随机腐蚀板的公式。最后，研究分析了不同位置的腐蚀效应，发现弧形板的中心区域对腐蚀最为敏感。

{"title":"Compression capacity of simply supported corroded cylindrical curved plates","authors":"Qian Yang , Zhongwei Zhao , Shuoran Li , Zhendong Zhang , Ni Zhang , Bingzhen Zhao","doi":"10.1016/j.oceaneng.2024.119628","DOIUrl":"10.1016/j.oceaneng.2024.119628","url":null,"abstract":"<div><div>Cylindrical curved plates are widely used in structures such as aircraft skins and marine vessels. Corrosion significantly affects the structural stability of these curved plates. A finite element model was established to analyze the influence of corrosion on the post-buckling strength of curved plates. The reliability of the developed stochastic finite element model was preliminarily verified through comparison with theoretical calculations. Stochastic numerical analysis revealed the effects of parameters such as corrosion depth, corrosion location, and geometric dimensions on the stability and load-bearing capacity of the curved plates. The study found that the width (<em>b</em>)and height (<em>a</em>) had no effect on compressive load-bearing capacity, while mesh size, curvature radius (<em>R</em>), and diameter-to-thickness ratio (<em>b</em>/<em>t</em>) had significant impacts. The impact of corrosion depth (<em>t</em><sub><em>c</em></sub>/<em>t</em>) was especially significant. This paper first proposed a theoretical formula to predict the reduction factor (<em>η</em>) for the compressive load-bearing capacity of uniformly corroded curved plates and then derived a formula for randomly corroded plates by modifying the equation for uniformly corroded plates. Finally, the study analyzed corrosion effects at different locations, revealing that the central region of the curved plate is the most sensitive to corrosion.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119628"},"PeriodicalIF":4.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An adaptive sliding mode control method for dynamic positioning vessel: Mitigating potential instability arising from auxiliary systems 用于动态定位船的自适应滑模控制方法：减轻辅助系统可能带来的不稳定性

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-13 DOI: 10.1016/j.oceaneng.2024.119680

Yutu Ye , Yiting Wang , Lei Wang , Xuefeng Wang , Meng Yuan

This paper presents an adaptive sliding mode control (SMC) strategy for dynamic positioning (DP) vessels with the model uncertainty, environmental disturbances, and input saturation. The adaptive updating laws for the parameter estimation are derived using Lyapunov theory. The low-level thrust allocation and the actuator limitations are considered. It is theoretically proved that all signals in the closed-loop system are uniformly ultimately bounded (UUB). The importance of the auxiliary system within the adaptive controller is highlighted, and potential instability issues when combined with thrust allocation are explored. Two methods to mitigate this instability are proposed and verified by numerical simulations. These methods achieve harmonious cooperation between high-level motion control and low-level thrust allocation by actively adjusting the target thrust values and auxiliary system parameters. Simulation results demonstrate that the proposed adaptive SMC are capable of maintaining DP vessel stability under the given uncertainties and disturbances.

本文针对具有模型不确定性、环境干扰和输入饱和的动态定位（DP）船舶提出了一种自适应滑模控制（SMC）策略。利用 Lyapunov 理论推导了参数估计的自适应更新规律。考虑了低水平推力分配和致动器限制。理论证明，闭环系统中的所有信号都是均匀最终有界的（UUB）。研究强调了自适应控制器中辅助系统的重要性，并探讨了与推力分配相结合时可能出现的不稳定性问题。提出了两种缓解这种不稳定性的方法，并通过数值模拟进行了验证。这些方法通过主动调整目标推力值和辅助系统参数，实现了高层运动控制和低层推力分配之间的和谐合作。仿真结果表明，所提出的自适应 SMC 能够在给定的不确定性和干扰下保持 DP 船舶的稳定性。

{"title":"An adaptive sliding mode control method for dynamic positioning vessel: Mitigating potential instability arising from auxiliary systems","authors":"Yutu Ye , Yiting Wang , Lei Wang , Xuefeng Wang , Meng Yuan","doi":"10.1016/j.oceaneng.2024.119680","DOIUrl":"10.1016/j.oceaneng.2024.119680","url":null,"abstract":"<div><div>This paper presents an adaptive sliding mode control (SMC) strategy for dynamic positioning (DP) vessels with the model uncertainty, environmental disturbances, and input saturation. The adaptive updating laws for the parameter estimation are derived using Lyapunov theory. The low-level thrust allocation and the actuator limitations are considered. It is theoretically proved that all signals in the closed-loop system are uniformly ultimately bounded (UUB). The importance of the auxiliary system within the adaptive controller is highlighted, and potential instability issues when combined with thrust allocation are explored. Two methods to mitigate this instability are proposed and verified by numerical simulations. These methods achieve harmonious cooperation between high-level motion control and low-level thrust allocation by actively adjusting the target thrust values and auxiliary system parameters. Simulation results demonstrate that the proposed adaptive SMC are capable of maintaining DP vessel stability under the given uncertainties and disturbances.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119680"},"PeriodicalIF":4.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the development of the vortex street between the wings of wave glider 波浪滑翔机机翼间涡街的发展研究

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-13 DOI: 10.1016/j.oceaneng.2024.119662

Yongguo Li , Kun Zhang , Xuan Tang , Caiyin Xu , Xiangyan Li

This study focused on the propulsion mechanism of wave gliders, which are small unmanned boats that utilize wave energy for propulsion. Numerical simulations were conducted to analyze the inter-wing vortex street and its impact on the propulsion force. The study involved constructing a 3D model of the wave glider, exploring the structure and function of its components, and introducing an innovative expanded wing structure for effective solar energy collection. A computational model was established to calculate the thrust of the serial airfoil propulsion system on the wave glider. The simulations investigated the development of the inter-wing vortex street under different flow velocities and wave parameters. The results demonstrated that the inter-wing vortex street had a significant effect on the propulsion force, especially when the inflow velocity and heave motion amplitude were above certain thresholds. Based on the simulation data, a mathematical model for thrust prediction was developed using grey system theory and a neural network. The model achieved a satisfactory prediction accuracy, with an error rate of 12.864%. This research provides valuable insights for optimizing the control model of wave gliders and improving their propulsion efficiency.

波浪滑翔机是一种利用波浪能进行推进的小型无人驾驶船只，本研究重点关注其推进机制。研究人员进行了数值模拟，以分析翼间涡街及其对推进力的影响。研究包括构建波浪滑翔机的三维模型，探索其各组成部分的结构和功能，并引入创新的扩展翼结构以有效收集太阳能。建立了一个计算模型来计算波浪滑翔机上串联翼面推进系统的推力。模拟研究了不同流速和波浪参数下翼间涡街的发展情况。结果表明，翼间涡街对推进力有显著影响，尤其是当流入速度和波浪运动振幅超过一定临界值时。根据模拟数据，利用灰色系统理论和神经网络建立了推力预测数学模型。该模型的预测精度令人满意，误差率为 12.864%。这项研究为优化波浪滑翔机的控制模型和提高其推进效率提供了有价值的见解。

{"title":"Study on the development of the vortex street between the wings of wave glider","authors":"Yongguo Li , Kun Zhang , Xuan Tang , Caiyin Xu , Xiangyan Li","doi":"10.1016/j.oceaneng.2024.119662","DOIUrl":"10.1016/j.oceaneng.2024.119662","url":null,"abstract":"<div><div>This study focused on the propulsion mechanism of wave gliders, which are small unmanned boats that utilize wave energy for propulsion. Numerical simulations were conducted to analyze the inter-wing vortex street and its impact on the propulsion force. The study involved constructing a 3D model of the wave glider, exploring the structure and function of its components, and introducing an innovative expanded wing structure for effective solar energy collection. A computational model was established to calculate the thrust of the serial airfoil propulsion system on the wave glider. The simulations investigated the development of the inter-wing vortex street under different flow velocities and wave parameters. The results demonstrated that the inter-wing vortex street had a significant effect on the propulsion force, especially when the inflow velocity and heave motion amplitude were above certain thresholds. Based on the simulation data, a mathematical model for thrust prediction was developed using grey system theory and a neural network. The model achieved a satisfactory prediction accuracy, with an error rate of 12.864%. This research provides valuable insights for optimizing the control model of wave gliders and improving their propulsion efficiency.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119662"},"PeriodicalIF":4.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simplified approach for analyzing thermal buckling of pipeline based on nonlinear Pasternak foundation model 基于非线性帕斯捷尔纳克地基模型的管道热屈曲简化分析方法

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-13 DOI: 10.1016/j.oceaneng.2024.119731

Songxian Wang , Yunpeng Zhang , Guosheng Jiang , Minjie Wen , Wenbing Wu

The modeling of the nonlinear pipeline-soil interaction under multiple stress conditions is the most dominant factor affecting the precise prediction of the thermal buckling of submarine pipelines at high temperatures. In this study, a nonlinear Pasternak foundation model (NPFM) is introduced to simulate the soil-pipeline interaction when the thermal buckling occurs. This model accounts for the nonlinear but continuous deformation of the seabed. To solve the proposed mathematical problems, an effective Newton's iterative computational program, combined with the finite difference method, is developed to analyze the nonlinear responses of the pipeline. Restricting the outcomes of the iteration to the permissible tolerance range enhances the precision of the computational analysis in this study. The reliability and applicability of this method are verified by comparing it with published results and predictions from six elastic foundation models based on different subgrade reaction moduli. The study further analyzes the influence of pipeline design parameters, buried depth, and backfill material on pipeline buckling behavior. The results indicate that increasing the outer diameter and buried depth significantly inhibits thermal buckling, while pipeline wall thickness and backfill material have a lesser impact.

多应力条件下非线性管道-土壤相互作用的建模是影响高温下海底管道热屈曲精确预测的最主要因素。本研究引入了非线性帕斯捷尔纳克地基模型（NPFM）来模拟热屈曲发生时土壤与管道的相互作用。该模型考虑了海底非线性但连续的变形。为解决提出的数学问题，开发了一种有效的牛顿迭代计算程序，并结合有限差分法来分析管道的非线性响应。本研究将迭代结果限制在允许的公差范围内，从而提高了计算分析的精度。通过与已公布的结果和基于不同基底反力模量的六个弹性地基模型的预测结果进行比较，验证了该方法的可靠性和适用性。研究进一步分析了管道设计参数、埋深和回填材料对管道屈曲行为的影响。结果表明，增加管道外径和埋设深度可明显抑制热屈曲，而管道壁厚和回填材料的影响较小。

{"title":"Simplified approach for analyzing thermal buckling of pipeline based on nonlinear Pasternak foundation model","authors":"Songxian Wang , Yunpeng Zhang , Guosheng Jiang , Minjie Wen , Wenbing Wu","doi":"10.1016/j.oceaneng.2024.119731","DOIUrl":"10.1016/j.oceaneng.2024.119731","url":null,"abstract":"<div><div>The modeling of the nonlinear pipeline-soil interaction under multiple stress conditions is the most dominant factor affecting the precise prediction of the thermal buckling of submarine pipelines at high temperatures. In this study, a nonlinear Pasternak foundation model (NPFM) is introduced to simulate the soil-pipeline interaction when the thermal buckling occurs. This model accounts for the nonlinear but continuous deformation of the seabed. To solve the proposed mathematical problems, an effective Newton's iterative computational program, combined with the finite difference method, is developed to analyze the nonlinear responses of the pipeline. Restricting the outcomes of the iteration to the permissible tolerance range enhances the precision of the computational analysis in this study. The reliability and applicability of this method are verified by comparing it with published results and predictions from six elastic foundation models based on different subgrade reaction moduli. The study further analyzes the influence of pipeline design parameters, buried depth, and backfill material on pipeline buckling behavior. The results indicate that increasing the outer diameter and buried depth significantly inhibits thermal buckling, while pipeline wall thickness and backfill material have a lesser impact.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119731"},"PeriodicalIF":4.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical investigation on the effects of stingray flapping amplitudes and counts on self-burial performance 黄貂鱼拍打幅度和次数对自埋性能影响的数值研究

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-13 DOI: 10.1016/j.oceaneng.2024.119747

Kai Ren , Zhier Chen , Yu Tian , Jiancheng Yu , Hongbo Li , Zhiduo Tan

Marine benthic organisms, including stingrays, utilize sediment for self-burial, providing an effective strategy for concealment and protection against currents. This study investigates the effects of stingray flapping amplitude and count on self-burial performance using a two-dimensional numerical model, and two self-burial strategies are proposed. The first involves a single large-amplitude flap, achieving high sand transport efficiency but demanding higher transient power. The second uses multiple medium-amplitude flaps, results in a greater burial depth with lower peak power requirements. The analysis reveals that effective self-burial is dependent on raising an adequate quantity of sand and ensuring its deposition on the stingray body. Vortex dynamics play a crucial role, with appropriate vortex strength and sand volume needed for complete body coverage. Furthermore, this study underscores the potential of these findings to inform the design of bio-inspired marine robots capable of self-burial, offering novel insights into the mechanics underlying stingray self-burial and its broader implications for underwater technology development.

包括黄貂鱼在内的海洋底栖生物利用沉积物进行自我掩埋，为隐蔽和抵御洋流提供了一种有效的策略。本研究利用二维数值模型研究了黄貂鱼拍打幅度和次数对自埋性能的影响，并提出了两种自埋策略。第一种是单个大振幅拍打，可实现较高的输沙效率，但需要较高的瞬态功率。第二种是使用多个中等振幅的襟翼，可实现更大的掩埋深度，但峰值功率要求较低。分析表明，有效的自埋取决于是否能扬起足够数量的沙子并确保其沉积在黄貂鱼身上。漩涡动力学起着至关重要的作用，需要适当的漩涡强度和沙量才能完全覆盖身体。此外，这项研究强调了这些发现的潜力，为设计能够自我掩埋的生物启发海洋机器人提供了信息，为黄貂鱼自我掩埋的基本力学及其对水下技术发展的广泛影响提供了新的见解。

{"title":"Numerical investigation on the effects of stingray flapping amplitudes and counts on self-burial performance","authors":"Kai Ren , Zhier Chen , Yu Tian , Jiancheng Yu , Hongbo Li , Zhiduo Tan","doi":"10.1016/j.oceaneng.2024.119747","DOIUrl":"10.1016/j.oceaneng.2024.119747","url":null,"abstract":"<div><div>Marine benthic organisms, including stingrays, utilize sediment for self-burial, providing an effective strategy for concealment and protection against currents. This study investigates the effects of stingray flapping amplitude and count on self-burial performance using a two-dimensional numerical model, and two self-burial strategies are proposed. The first involves a single large-amplitude flap, achieving high sand transport efficiency but demanding higher transient power. The second uses multiple medium-amplitude flaps, results in a greater burial depth with lower peak power requirements. The analysis reveals that effective self-burial is dependent on raising an adequate quantity of sand and ensuring its deposition on the stingray body. Vortex dynamics play a crucial role, with appropriate vortex strength and sand volume needed for complete body coverage. Furthermore, this study underscores the potential of these findings to inform the design of bio-inspired marine robots capable of self-burial, offering novel insights into the mechanics underlying stingray self-burial and its broader implications for underwater technology development.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119747"},"PeriodicalIF":4.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deep learning-based multilabel compound-fault diagnosis in centrifugal pumps 基于深度学习的离心泵多标签复合故障诊断

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-13 DOI: 10.1016/j.oceaneng.2024.119697

Lizhe Jiang , Hongze Du , Yufeng Bu , Chunyu Zhao , Hailong Lu , Jun Yan

In this study, the issue of centrifugal pumps used in marine engineering is addressed, as they are susceptible to malfunction owing to long-term operation in highly corrosive seawater and extreme weather conditions, resulting in operational interruptions and safety risks. We propose a high-precision intelligent fault-diagnosis method for multiple fault types based on deep learning. In this method, continuous wavelet transform is firstly employed to extract signal time–frequency domain features. Subsequently, the Swin transformer model is used to process the wavelet time–frequency images converted from signals. Finally, multilabel classification methods are combined to diagnose various complex faults. The effectiveness of the proposed method is validated using a dataset obtained from simulation experiments pertaining to centrifugal-pump faults. The results show that the proposed method achieves 100% accuracy in diagnosing 27 types of faults and provides excellent diagnosis even under limited compound-fault samples, thus offering an efficient and practical method for fault diagnosis in centrifugal pumps used in marine engineering.

本研究探讨了海洋工程中使用的离心泵问题，因为这些泵长期在高腐蚀性海水和极端天气条件下运行，很容易出现故障，导致运行中断和安全风险。我们提出了一种基于深度学习的多故障类型高精度智能故障诊断方法。在该方法中，首先采用连续小波变换来提取信号的时频域特征。随后，使用 Swin 变换器模型处理信号转换而来的小波时频图像。最后，结合多标签分类方法诊断各种复杂故障。利用从离心泵故障模拟实验中获得的数据集验证了所提方法的有效性。结果表明，所提出的方法在诊断 27 种故障时达到了 100% 的准确率，即使在有限的复合故障样本下也能提供出色的诊断，从而为海洋工程中使用的离心泵故障诊断提供了一种高效实用的方法。

{"title":"Deep learning-based multilabel compound-fault diagnosis in centrifugal pumps","authors":"Lizhe Jiang , Hongze Du , Yufeng Bu , Chunyu Zhao , Hailong Lu , Jun Yan","doi":"10.1016/j.oceaneng.2024.119697","DOIUrl":"10.1016/j.oceaneng.2024.119697","url":null,"abstract":"<div><div>In this study, the issue of centrifugal pumps used in marine engineering is addressed, as they are susceptible to malfunction owing to long-term operation in highly corrosive seawater and extreme weather conditions, resulting in operational interruptions and safety risks. We propose a high-precision intelligent fault-diagnosis method for multiple fault types based on deep learning. In this method, continuous wavelet transform is firstly employed to extract signal time–frequency domain features. Subsequently, the Swin transformer model is used to process the wavelet time–frequency images converted from signals. Finally, multilabel classification methods are combined to diagnose various complex faults. The effectiveness of the proposed method is validated using a dataset obtained from simulation experiments pertaining to centrifugal-pump faults. The results show that the proposed method achieves 100% accuracy in diagnosing 27 types of faults and provides excellent diagnosis even under limited compound-fault samples, thus offering an efficient and practical method for fault diagnosis in centrifugal pumps used in marine engineering.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119697"},"PeriodicalIF":4.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fast prediction of the long-range structural acoustic radiation in the stratified ocean 分层海洋中长程结构声辐射的快速预测

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-13 DOI: 10.1016/j.oceaneng.2024.119673

Ruixin Nie , Tengjiao He , Jun Fan , Kaiqi Zhao , Bin Wang

In this study, we propose an efficient method for predicting three-dimensional acoustic radiation from arbitrary structures immersed in a shallow-water waveguide. By incorporating the finite element method (FEM) and the wave superposition method (WSM), the detailed acoustic radiation from the vibrating structure in the near field is calculated by numerically evaluating the source strength integral that represents the Helmholtz exterior problem. Transitioning to the far-field region, where the structural acoustic radiation is characterized by the source directionality, an analytical, normal-mode expression for the source-strength integral is derived, representing the structural acoustic radiation as a sum over propagating eigenmodes, with the modal excitation determined by the directionality of the acoustic radiation mode. This represents a significant improvement in numerical efficiency by reducing computational complexity, especially for high-frequency and long-range predictions. The critical distance distinguishing the near-field and far-field regions is discussed in detail, determined by the horizontal wavenumber and structure size. Numerical simulations demonstrate the effectiveness of the proposed method and reveal the coupling mechanism between the structural acoustic radiation and the underwater acoustic propagation. The proposed method is adaptable to optimize the passive sonar performance by achieving the real-time prediction of the structural acoustic radiation in realistic ocean-acoustic environments.

在本研究中，我们提出了一种预测浸入浅水波导中的任意结构产生的三维声辐射的有效方法。通过结合有限元法（FEM）和波叠加法（WSM），对代表亥姆霍兹外部问题的声源强度积分进行数值评估，从而计算出振动结构在近场的详细声辐射。过渡到结构声辐射以声源方向性为特征的远场区域时，源强度积分的解析法向模式表达式被推导出来，将结构声辐射表示为传播特征模式的总和，模式激励由声辐射模式的方向性决定。这大大提高了数值效率，降低了计算复杂度，尤其是在高频和远距离预测方面。详细讨论了区分近场和远场区域的临界距离，该距离由水平波数和结构尺寸决定。数值模拟证明了所提方法的有效性，并揭示了结构声辐射与水下声传播之间的耦合机制。所提出的方法可以在现实的海洋声学环境中实现结构声辐射的实时预测，从而优化被动声纳的性能。

{"title":"Fast prediction of the long-range structural acoustic radiation in the stratified ocean","authors":"Ruixin Nie , Tengjiao He , Jun Fan , Kaiqi Zhao , Bin Wang","doi":"10.1016/j.oceaneng.2024.119673","DOIUrl":"10.1016/j.oceaneng.2024.119673","url":null,"abstract":"<div><div>In this study, we propose an efficient method for predicting three-dimensional acoustic radiation from arbitrary structures immersed in a shallow-water waveguide. By incorporating the finite element method (FEM) and the wave superposition method (WSM), the detailed acoustic radiation from the vibrating structure in the near field is calculated by numerically evaluating the source strength integral that represents the Helmholtz exterior problem. Transitioning to the far-field region, where the structural acoustic radiation is characterized by the source directionality, an analytical, normal-mode expression for the source-strength integral is derived, representing the structural acoustic radiation as a sum over propagating eigenmodes, with the modal excitation determined by the directionality of the acoustic radiation mode. This represents a significant improvement in numerical efficiency by reducing computational complexity, especially for high-frequency and long-range predictions. The critical distance distinguishing the near-field and far-field regions is discussed in detail, determined by the horizontal wavenumber and structure size. Numerical simulations demonstrate the effectiveness of the proposed method and reveal the coupling mechanism between the structural acoustic radiation and the underwater acoustic propagation. The proposed method is adaptable to optimize the passive sonar performance by achieving the real-time prediction of the structural acoustic radiation in realistic ocean-acoustic environments.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119673"},"PeriodicalIF":4.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nonlinear fracture analysis of misaligned clad pipes with semi-elliptical surface cracks under large deformation 大变形下带有半椭圆表面裂缝的错位包覆管道的非线性断裂分析

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119740

Hongyang Hu , Yao Zhang

The integrity of offshore oil pipes becomes increasingly important. The clad pipes are commonly used for oil transportation. These pipes often experience plastic deformations with a global strain of up to 2%, making the investigation of the weld crack flaws essential. Previous research has analyzed the failure responses and local buckling of clad pipes subjected to large deformation. This study uses validated 3D finite element (FE) models to investigate the nonlinear elastic-plastic fracture behavior of equal- and unequal-diameter misaligned clad pipes with semi-elliptical surface cracks subjected to large deformation. The effect of crack depth to wall thickness ratio, crack length to depth ratio, weld misalignment level, internal pressure, load condition, strength mismatch, and the location of crack on the crack tip opening displacement (CTOD) has been elaborated. The effectiveness of BS 7910 (2019) Option 2 assessment equations against FE models is evaluated, showing that the BS 7910 (2019) Option 2 assessment equations are more conservative than the results from FE models. Moreover, a failure assessment diagram (FAD) using the CTOD obtained by the FE models is developed to accommodate the effect of weld misalignment on the nonlinear fracture behavior of misaligned clad pipes with surface semi-elliptical cracks under large deformation.

海上石油管道的完整性变得越来越重要。覆层管道通常用于石油运输。这些管道通常会发生塑性变形，整体应变高达 2%，因此对焊接裂缝缺陷的研究至关重要。以往的研究分析了覆层管道在大变形情况下的失效响应和局部屈曲。本研究采用经过验证的三维有限元 (FE) 模型，研究了具有半椭圆形表面裂纹的等径和不等径错位堆焊管道在承受大变形时的非线性弹塑性断裂行为。研究阐述了裂纹深度与壁厚比、裂纹长度与深度比、焊接错位程度、内压、载荷条件、强度不匹配以及裂纹位置对裂纹尖端张开位移（CTOD）的影响。评估了 BS 7910 (2019) 选项 2 评估方程与 FE 模型的有效性，结果表明 BS 7910 (2019) 选项 2 评估方程比 FE 模型的结果更加保守。此外，利用 FE 模型获得的 CTOD 开发了失效评估图 (FAD)，以适应焊接错位对具有表面半椭圆形裂纹的错位覆层管道在大变形下的非线性断裂行为的影响。

{"title":"Nonlinear fracture analysis of misaligned clad pipes with semi-elliptical surface cracks under large deformation","authors":"Hongyang Hu , Yao Zhang","doi":"10.1016/j.oceaneng.2024.119740","DOIUrl":"10.1016/j.oceaneng.2024.119740","url":null,"abstract":"<div><div>The integrity of offshore oil pipes becomes increasingly important. The clad pipes are commonly used for oil transportation. These pipes often experience plastic deformations with a global strain of up to 2%, making the investigation of the weld crack flaws essential. Previous research has analyzed the failure responses and local buckling of clad pipes subjected to large deformation. This study uses validated 3D finite element (FE) models to investigate the nonlinear elastic-plastic fracture behavior of equal- and unequal-diameter misaligned clad pipes with semi-elliptical surface cracks subjected to large deformation. The effect of crack depth to wall thickness ratio, crack length to depth ratio, weld misalignment level, internal pressure, load condition, strength mismatch, and the location of crack on the crack tip opening displacement (CTOD) has been elaborated. The effectiveness of BS 7910 (2019) Option 2 assessment equations against FE models is evaluated, showing that the BS 7910 (2019) Option 2 assessment equations are more conservative than the results from FE models. Moreover, a failure assessment diagram (FAD) using the CTOD obtained by the FE models is developed to accommodate the effect of weld misalignment on the nonlinear fracture behavior of misaligned clad pipes with surface semi-elliptical cracks under large deformation.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119740"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A theoretical study of wave-induced response of buried long submarine cables 埋设的长海底电缆的波浪诱导响应理论研究

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119612

Zheng Wei, Jing Yuan

Subsea power cable, which is essential for offshore renewable energy, is often buried within the seabed in coastal areas to ensure safety. Nevertheless, waves can produce dynamic pore pressure within the seabed, and hence cause some dynamic response of the cable, which has been rarely studied. To close this gap, a simple analytical model is developed for obtaining harmonic oscillation of a deeply buried cable. An approximated solution for wave-induced force is derived based on the assumption of large embedding depth. The cable is treated as an infinitely long Euler–Bernoulli beam buried in a viscoelastic foundation. Harmonic solution of the cable’s deformation in the vertical and transverse direction is obtained for an arbitrary wave-cable angle. A parametric analysis is carried out for typical cables. It is found that there exists an optimal wave period that maximizes the cable’s response under a given water depth. Under breaking-wave conditions, the wave-induced cable deformation is still sub-millimetre, showing that seepage flow does not pose a big threat. Finally, the shape of deformed cable is found to be helix when the wave-cable angle is between 0 and

π / 2

.

海底电力电缆是海上可再生能源的重要组成部分，为确保安全，通常埋设在沿海地区的海底。然而，波浪会在海床内产生动态孔隙压力，从而引起电缆的一些动态响应，而这方面的研究却很少。为了填补这一空白，本文建立了一个简单的分析模型，用于获取深埋电缆的谐波振荡。基于大埋深假设，得出了波浪诱导力的近似解。电缆被视为埋在粘弹性地基中的无限长欧拉-伯努利梁。在任意波-缆角度下，得到了缆索在垂直和横向变形的谐波解。对典型缆索进行了参数分析。结果发现，在给定水深条件下，存在一个能使缆索响应最大化的最佳波浪周期。在破浪条件下，波浪引起的缆索变形仍在毫米以下，这表明渗流不会造成很大威胁。最后，当波浪与缆索的夹角在 0 至 π/2 之间时，变形缆索的形状为螺旋形。

{"title":"A theoretical study of wave-induced response of buried long submarine cables","authors":"Zheng Wei, Jing Yuan","doi":"10.1016/j.oceaneng.2024.119612","DOIUrl":"10.1016/j.oceaneng.2024.119612","url":null,"abstract":"<div><div>Subsea power cable, which is essential for offshore renewable energy, is often buried within the seabed in coastal areas to ensure safety. Nevertheless, waves can produce dynamic pore pressure within the seabed, and hence cause some dynamic response of the cable, which has been rarely studied. To close this gap, a simple analytical model is developed for obtaining harmonic oscillation of a deeply buried cable. An approximated solution for wave-induced force is derived based on the assumption of large embedding depth. The cable is treated as an infinitely long Euler–Bernoulli beam buried in a viscoelastic foundation. Harmonic solution of the cable’s deformation in the vertical and transverse direction is obtained for an arbitrary wave-cable angle. A parametric analysis is carried out for typical cables. It is found that there exists an optimal wave period that maximizes the cable’s response under a given water depth. Under breaking-wave conditions, the wave-induced cable deformation is still sub-millimetre, showing that seepage flow does not pose a big threat. Finally, the shape of deformed cable is found to be helix when the wave-cable angle is between 0 and <span><math><mrow><mi>π</mi><mo>/</mo><mn>2</mn></mrow></math></span>.</div></div>","PeriodicalId":19403,"journal":{"name":"Ocean Engineering","volume":"314 ","pages":"Article 119612"},"PeriodicalIF":4.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142660410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Floating offshore wind turbine nonlinear model predictive control optimisation method 漂浮式海上风力涡轮机非线性模型预测控制优化方法

IF 4.6 2区工程技术 Q1 ENGINEERING, CIVIL

Ocean Engineering

Pub Date : 2024-11-12 DOI: 10.1016/j.oceaneng.2024.119754

Javier López-Queija , Josu Jugo , Ander Tena , Eider Robles , Eneko Sotomayor

This paper presents a novel control parameter optimisation methodology for nonlinear model predictive control for floating offshore wind turbine operation, computing optimisation weights as environment conditions dependent variables. The main objective is to reduce the required time to define the optimal control parameters for the nonlinear control strategy, using an automated approach. To achieve this, an optimisation methodology based on extreme operational gust conditions is applied by employing a Random Walk-type Monte Carlo procedure. The primary aim is to introduce an advanced control design approach that addresses concerns related to the efficient power generation and longevity of floating systems, particularly considering the growing scale of wind turbines and the dynamic behaviour of floating platforms, which increase the system overall costs. The resulting optimised controller is also evaluated against state-of-the-art feedback-based control strategies in different operational environmental conditions.

本文针对浮式海上风力涡轮机运行的非线性模型预测控制，提出了一种新颖的控制参数优化方法，将优化权重作为环境条件相关变量进行计算。其主要目的是采用自动化方法，缩短为非线性控制策略定义最佳控制参数所需的时间。为此，通过采用随机漫步式蒙特卡罗程序，应用了基于极端运行阵风条件的优化方法。其主要目的是引入一种先进的控制设计方法，以解决与浮动系统的高效发电和使用寿命相关的问题，特别是考虑到风力涡轮机规模的不断扩大和浮动平台的动态行为会增加系统的总体成本。此外，还针对不同运行环境条件下基于反馈的先进控制策略，对优化后的控制器进行了评估。

引用次数: 0