Marine Structures最新文献_第3页

A Kane-based time domain hydrodynamic analysis method for hinged multi-floating bodies under irregular wave conditions 不规则波浪条件下铰链式多浮体的基于 Kane 的时域流体力学分析方法

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-13 DOI: 10.1016/j.marstruc.2024.103708

Junyi Liu , Xujun Chen , Song Ji , Guizhang Hu , Yuji Miao

To better investigate the hydrodynamic responses of hinged multiple floating body system in irregular waves, a novel Kane-based time domain model is established and the associated calculation program is developed in conjunction with the potential theory and the catenary theory. The reduced Kane equations suitable for the dynamic response of moored multi-floating body system with hinges in irregular waves are firstly deduced, and then an experiment of hinged floating bridge performed in a wave tank is briefly introduced. Following the validation of the Kane-based model based on the comparisons between the predictions and the observations of the model test in several irregular wave conditions, an investigation of the influence of wave parameters in JONSWAP spectrum on the dynamic response of the system is further conducted. The associated results indicate that the heave motions, the pitch motions and the vertical connector loads of the hinged pontoons decrease nonlinearly with the growth of peak frequency under general sea conditions, while the peak enhancement factor has little influence on the dynamic responses of the hinged floating bridge. In addition, the first pontoon in the hinged floating bridge shows the greatest motion responses, and more attention should be paid to its dynamic response during analysing the security of hinged floating bridge.

为了更好地研究铰链式多浮体系统在不规则波浪中的水动力响应，结合势理论和导管理论，建立了一个新颖的基于 Kane 的时域模型，并开发了相关的计算程序。首先推导出适用于带铰链的系泊多浮体系统在不规则波浪中动态响应的还原凯恩方程，然后简要介绍了在波浪槽中进行的铰链浮桥实验。根据模型试验在几种不规则波浪条件下的预测值和观测值之间的比较，对基于 Kane 的模型进行了验证，然后进一步研究了 JONSWAP 波谱中的波浪参数对系统动态响应的影响。相关结果表明，在一般海况下，铰链浮桥的翻腾运动、俯仰运动和垂直连接器载荷随峰值频率的增长而非线性减小，而峰值增强因子对铰链浮桥的动态响应影响不大。此外，铰链浮桥中的第一个浮桥的运动响应最大，在分析铰链浮桥的安全性时应更加关注其动态响应。

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引用次数: 0

Support condition identification for monopile-supported offshore wind turbines based on time domain model updating 基于时域模型更新的单桩支撑海上风力涡轮机支撑条件识别

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-13 DOI: 10.1016/j.marstruc.2024.103709

Jun Liang , Bence Kato , Yuhao Fu , Ying Wang

The soil-structure interaction (SSI), which presents intricate nonlinearities and inevitably varies throughout the structural lifetime, is critical for the structural performance of monopile-supported offshore wind turbines (OWTs). Since its direct monitoring is challenging, a new time domain model updating method for support condition identification of monopile-supported OWTs is proposed in this study. A distributed spring-dashpot model incorporating nonlinear stiffness and damping is used to simulate the SSI. Time-domain responses of the OWT are used to construct the objective function for model updating. Vibration tests on a scaled model of the DTU 10 MW OWT are performed in the laboratory to verify the proposed method. The model updating results based on the test data show that the mean squared error between simulated and measured responses is less than 0.011, significantly smaller than the results obtained by using the traditional frequency-domain model updating methods. These findings demonstrated that the proposed distributed spring-dashpot model can accurately capture the complex nonlinearity in SSI and that the proposed time-domain model updating method can be used to identify the support conditions of monopile-supported OWTs. The methodology is expected to contribute significantly to enhancing the efficiency of the operation and maintanence for OWTs.

土壤-结构相互作用（SSI）具有复杂的非线性，在整个结构寿命期间不可避免地会发生变化，这对单桩支撑海上风力涡轮机（OWT）的结构性能至关重要。由于对其进行直接监测具有挑战性，本研究提出了一种新的时域模型更新方法，用于识别单桩支撑海上风力涡轮机的支撑状况。采用包含非线性刚度和阻尼的分布式弹簧-底盘模型来模拟 SSI。OWT 的时域响应用于构建模型更新的目标函数。在实验室中对 DTU 10 MW OWT 的缩放模型进行了振动测试，以验证所提出的方法。基于测试数据的模型更新结果表明，模拟响应与测量响应之间的均方误差小于 0.011，明显小于使用传统频域模型更新方法得到的结果。这些研究结果表明，所提出的分布式弹簧-底座模型能够准确捕捉 SSI 中的复杂非线性，而且所提出的时域模型更新方法可用于确定单桩支撑 OWT 的支撑条件。该方法有望极大地提高风电场的运行和维护效率。

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引用次数: 0

Axial Winkler springs for vertically loaded piles 用于垂直荷载桩的轴向温克勒弹簧

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-13 DOI: 10.1016/j.marstruc.2024.103707

Rui He , Dan Wang , Amir M. Kaynia

Axial soil spring stiffness along piles is crucial in the dynamic analysis of offshore jacket foundations. This study proposes a rigorous analytical model for vertically loaded piles embedded in a soil layer based on Green's functions. The stiffness of both end-bearing piles and floating piles can be obtained from this model, which is different from previous studies that have considered end-bearing piles and floating piles by two different models. The study investigates various factors affecting the soil springs. The actual distribution of soil spring stiffness is complicated, even for homogeneous soils. To facilitate the engineering application, the soil spring stiffness is averaged to uniform distribution according to the equivalent work method. The pile with relative pile-soil axial stiffness greater than 1.5 can be treated as a rigid pile in which the soil spring stiffness depends primarily on the pile slenderness ratios. For other cases, referred to as flexible piles, the soil spring stiffness depends on both pile slenderness ratio and pile-soil modulus ratio. Simplified analytical expressions are proposed for the averaged soil spring stiffness of both rigid and flexible piles in different soil profiles. Besides, the soil layer effect is significant for short piles but negligible for long piles.

沿桩的轴向土壤弹簧刚度对海上夹层地基的动态分析至关重要。本研究基于格林函数，为嵌入土层的垂直荷载桩提出了一个严格的分析模型。通过该模型可获得端承桩和浮动桩的刚度，这与以往研究中通过两种不同模型考虑端承桩和浮动桩的做法不同。该研究调查了影响土体弹簧的各种因素。土体弹簧刚度的实际分布比较复杂，即使是均质土也不例外。为便于工程应用，根据等效功法将土弹簧刚度平均为均匀分布。桩-土轴向相对刚度大于 1.5 的桩可视为刚性桩，其土弹簧刚度主要取决于桩的细长比。对于其他情况（称为柔性桩），土的弹簧刚度取决于桩的细长比和桩-土模量比。针对不同土壤剖面中刚性桩和柔性桩的平均土壤弹簧刚度，提出了简化的分析表达式。此外，土层对短桩的影响很大，但对长桩的影响可以忽略不计。

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引用次数: 0

Shaking table tests of offshore wind turbine systems with a suction bucket foundation in sandy seabed subject to earthquake and wind loads 在承受地震和风荷载的沙质海床上对带有吸斗基础的海上风力涡轮机系统进行振动台试验

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-09 DOI: 10.1016/j.marstruc.2024.103706

Bin Gao , Chong Li , Feilong Zhou , Wenxuan Zhu , Guanlin Ye

With the rapid development of offshore wind power industries in China, a significant proportion of existing and planned offshore wind farms are located near seismically active zones with liquefaction potential. Seismic liquefaction threaten the safety of suction bucket foundations supported offshore wind turbines. The shaking table tests for sandy seabed - suction bucket - offshore wind turbine system were carried out under combined wind and earthquake loads. The response of the ground and structure under seismic and wind loads was investigated carefully. The effects of wind load, seismic load, and drainage holes in the top cover of the suction bucket on the dynamic response of this system were obtained. Test results indicate that the increase of peak acceleration results in the increase of seabed, turbine response, excess pore water pressure and wind turbine's rotation. The influence of 2 Hz sine wave on offshore wind turbines is greater than that of 4 Hz. The tilt of the wind turbine under the combined action of wind and earthquake is greater than that under the action of wind load or earthquake alone. Top drainage of the bucket foundation will reduce the seismic capacity of the suction bucket foundation. The research can provide reference for the seismic design of suction buckets for offshore wind turbines.

随着中国海上风电产业的快速发展，现有和规划中的海上风电场有相当一部分位于具有液化潜力的地震活跃区附近。地震液化对支撑海上风力涡轮机的吸油桶基础的安全构成威胁。在风荷载和地震荷载的共同作用下，对砂质海床-吸油桶-海上风力涡轮机系统进行了振动台试验。对地面和结构在地震和风荷载下的响应进行了仔细研究。获得了风荷载、地震荷载和吸水桶顶盖排水孔对该系统动态响应的影响。试验结果表明，峰值加速度的增加会导致海床、涡轮机响应、多余孔隙水压力和涡轮机旋转的增加。2 赫兹正弦波对海上风力涡轮机的影响大于 4 赫兹正弦波。风力和地震共同作用下风力涡轮机的倾斜度大于风力荷载或地震单独作用下的倾斜度。吊桶基础顶部排水会降低吸水吊桶基础的抗震能力。该研究可为海上风力涡轮机吸水斗的抗震设计提供参考。

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引用次数: 0

Progressive collapse response and ultimate strength evaluation of stiffened plates with welding residual stress under combined biaxial cyclic loads and lateral pressure 焊接残余应力加劲板在双轴循环载荷和侧压力联合作用下的渐进坍塌响应和极限强度评估

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-09 DOI: 10.1016/j.marstruc.2024.103703

Dongyang Li , Zhen Chen

Stiffened plates used in bottom structures of ships are commonly subjected to multiaxial loading in harsh sea state. Thus, understanding their collapse behaviour under combined loads is highly valuable, and numerical simulations can provide accurate insights into this topic. The current research is the first to deal with the ultimate strength characteristics and assessment of initially deflected stiffened plates with welding residual stress (WRS) under combined biaxial cyclic loads and lateral pressure. Finite element analysis is conducted extensively to obtain the numerical results of longitudinal cyclic ultimate strength considering geometric and material nonlinearities with the aid of secondary development of ABAQUS software. It is found that the cyclic ultimate strength is governed by the coupling effects of structural dimensions, longitudinal and transverse residual stresses as well as transverse cyclic compressive/tensile loads and lateral pressure. A series of significant findings observed from this paper are presented in detail aiming to improve the ultimate limit state (ULS) design of ship structures. Based on sufficient sample points, four different machine learning (ML) models are trained maturely to predict the cyclic ultimate strength, including back propagation neural network (BPNN), support vector regression (SVR), random forest (RF) and radial basis function (RBF) network. Performance of these models is compared objectively using statistical metrics.

用于船底结构的加劲板在恶劣海况下通常会承受多轴载荷。因此，了解它们在组合载荷作用下的坍塌行为非常有价值，而数值模拟可以为这一课题提供准确的见解。目前的研究首次涉及焊接残余应力（WRS）的初始偏转加劲板在组合双轴循环载荷和侧压力下的极限强度特性和评估。在 ABAQUS 软件二次开发的帮助下，考虑到几何和材料非线性因素，进行了广泛的有限元分析，以获得纵向循环极限强度的数值结果。分析发现，循环极限强度受结构尺寸、纵向和横向残余应力以及横向循环压缩/拉伸载荷和侧压力的耦合效应制约。本文详细介绍了一系列重要发现，旨在改进船舶结构的极限状态（ULS）设计。基于足够的样本点，对四种不同的机器学习（ML）模型进行了成熟的训练，以预测循环极限强度，包括反向传播神经网络（BPNN）、支持向量回归（SVR）、随机森林（RF）和径向基函数（RBF）网络。使用统计指标对这些模型的性能进行了客观比较。

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引用次数: 0

Accuracy verification of the 2D spectral AIS method by the hull monitoring data 通过船体监测数据验证二维光谱 AIS 方法的准确性

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-07 DOI: 10.1016/j.marstruc.2024.103704

Masayoshi Oka, Yusuke Komoriyama, Chong Ma

Accuracy validation of the 2D spectral AIS method (AIS method using two-dimensional wave spectrum; 2D-AIS method) using hull monitoring data of a large ore carrier is discussed. The AIS method predicts the response of actual ships using AIS-based ship position data, hindcast wave data, and response characteristics data. The conventional AIS method uses representative parameters(

H

,

T

,

θ

) from wave spectrum modeling. The modeling involves many uncertainties. By using the 2D wave spectrum as it is, the effect of uncertainties associated with wave spectrum modeling is investigated. Compared to the analysis of the monitoring data conducted in this study, it was found that the 2D-AIS method improves the accuracy to about 15 %, while the conventional AIS method shows an error of up to about 35 % compared to the actual measurements in the long-term maximum expected values. This enhancement is attributed to the inability of the modeled wave spectrum to accurately represent the two-peak wave spectrum observed in extreme sea states, leading to a deficiency in reproducing wave frequency components corresponding to peak frequencies of the response. The findings underscore the effectiveness of the 2D-AIS method in refining long-term hull stress estimations, thus offering valuable insights for enhancing the safety and performance of hull structures.

讨论了利用一艘大型矿石运输船的船体监测数据对二维波谱 AIS 方法（使用二维波谱的 AIS 方法；2D-AIS 方法）进行精度验证的问题。AIS 方法利用基于 AIS 的船位数据、后报波浪数据和响应特性数据预测实际船舶的响应。传统的 AIS 方法使用波谱建模中的代表性参数（H、T、θ）。建模涉及许多不确定因素。通过使用二维波谱，研究了与波谱建模相关的不确定性的影响。与本研究进行的监测数据分析相比，发现二维 AIS 方法将精度提高了约 15%，而传统 AIS 方法与实际测量值相比，在长期最大预期值方面的误差高达约 35%。这种提高归因于建模波谱无法准确表示在极端海况下观测到的双峰值波谱，导致无法再现与响应峰值频率相对应的波频成分。这些发现强调了二维-AIS 方法在完善长期船体应力估计方面的有效性，从而为提高船体结构的安全性和性能提供了宝贵的见解。

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引用次数: 0

A deep learning model for predicting mechanical behaviors of dynamic power cable of offshore floating wind turbine 用于预测海上浮式风力涡轮机动态电力电缆机械行为的深度学习模型

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-07 DOI: 10.1016/j.marstruc.2024.103705

Jin Liu, Binbin Li

Dynamic power cable acts as both electricity current channel and information channel between offshore floating wind turbine and substation. Key role as it plays, the mechanical behaviors of dynamic power cable in operation is complicated, owing to the multiple internal loads involved in the cross section and the drastic stress distribution along the cable. In this paper, a multi-task integrated model based on LSTM is proposed to realize both the tension and the bending moment prediction at several fatigue-prone locations. Regarding the parameter combination in high dimension and time-consuming search for the optimum, halving grid search algorithm is applied to conduct hyper-parameters optimization with higher efficiency over wider range. Additionally, due to the motion effects brought by the buoyancy section, the prediction accuracy of the model at locations other than the hang-off point is lower, which is resolved by introducing an subsea sensor at the hog bend to provide additional 3-DOF motion inputs. The improvement brought by the additional inputs at the other points than the hang-off point can be up to 10%. The reliability of the multi-task integrated model is evaluated in a stochastic irregular wave generated by a different random seed as well as wave parameters scaled at different ratios, and a satisfying consistency is observed. Furthermore, the proposed model is applied in extreme sea state, in which the model exhibits comparable performance with its performance in operational sea state. The desirable performance in both the operational and extreme sea states demonstrates the robustness of the model, and implies its potential in more various sea states.

动态电力电缆既是海上浮动风力涡轮机与变电站之间的电流通道，也是信息通道。动态电力电缆作为海上浮式风力涡轮机与变电站之间的电流通道和信息通道，其作用十分关键，但由于其横截面涉及多个内部载荷，且沿电缆应力分布剧烈，因此其运行时的力学行为十分复杂。本文提出了一种基于 LSTM 的多任务集成模型，以实现多个易疲劳位置的拉力和弯矩预测。针对高维度参数组合和最优搜索耗时的问题，本文采用减半网格搜索算法，在更大范围内以更高的效率进行超参数优化。此外，由于浮力部分带来的运动效应，模型在悬挂点以外位置的预测精度较低，通过在猪弯处引入海底传感器提供额外的 3-DOF 运动输入解决了这一问题。除悬挂点外，其他位置的额外输入可提高 10%。在由不同随机种子以及不同比例的波浪参数产生的随机不规则波浪中，对多任务综合模型的可靠性进行了评估，结果表明其一致性令人满意。此外，还在极端海况下应用了所提出的模型，该模型在极端海况下的表现与其在运行海况下的表现相当。在工作海况和极端海况下的理想表现证明了该模型的鲁棒性，并意味着其在更多不同海况下的应用潜力。

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引用次数: 0

Tendon fatigue analysis of tension leg platform using a new time-domain quasi-dynamic method 使用新型时域准动态方法分析拉伸腿平台的肌腱疲劳问题

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-04 DOI: 10.1016/j.marstruc.2024.103701

Binbin Li , Wei Huang , Xiaobo Chen

Due to the non-Gaussian characteristics of the tendon tension response of tension leg platform (TLP), the common statistical model is not adequate to estimate the fatigue damage accurately in the frequency domain, thus the time domain analysis is required. A new quasi-dynamic method is proposed to calculate the tendon tension response considering various factors. An equivalent analytical tendon model is employed and the post-treatment has been carried out for the reconstruction of the high-frequency stress response based on the vertical motion QTFs of each tendon by HydroSTAR. Forty sets of environmental cases are extracted from a scatter diagram. The rainflow counting method is applied to deal with the stress time series and the fatigue damage can be obtained combined with the relevant S-N curve. The number of cycles of tension for each tendon is discussed, considering the contribution of the first-order wave load, the second-order diff-frequency wave load, and the second-order sum-frequency wave load. The comparison of annual fatigue damage based on the quasi-dynamic method and coupled method by Orcaflex is carried out. The study proves that the quasi-dynamic method is an efficient way to estimate the fatigue life of each tendon in the time domain considering numerous cases of discrete sea states.

由于张力腿平台（TLP）的肌腱张力响应具有非高斯特性，普通的统计模型不足以在频域上准确估计疲劳损伤，因此需要进行时域分析。考虑到各种因素，提出了一种新的准动态方法来计算肌腱拉伸响应。该方法采用了等效分析肌腱模型，并通过 HydroSTAR 根据每根肌腱的垂直运动 QTFs 进行了后处理，以重建高频应力响应。从散点图中提取了 40 组环境案例。采用雨流计数法处理应力时间序列，并结合相关的 S-N 曲线得出疲劳损伤。考虑到一阶波载荷、二阶差频波载荷和二阶和频波载荷的贡献，讨论了每根肌腱的拉伸循环次数。比较了基于准动态法和 Orcaflex 耦合法的年疲劳损伤。研究证明，考虑到离散海况的多种情况，准动态法是在时域内估算每根肌腱疲劳寿命的有效方法。

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引用次数: 0

Experimental investigation of nonlinear springing of ultra-large container ship in regular waves 超大型集装箱船在规则波浪中的非线性弹跳实验研究

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-04 DOI: 10.1016/j.marstruc.2024.103697

Hailong Si , Chao Tian , Jun Yang , Yanchao Geng , Nan Zhao , Jiajun Hu , Junhua Zhan

The issue of ship structural fatigue strength caused by springing is receiving increasing attention from designers. To investigate nonlinear springing more precisely on ultralarge container ships that have large-opening structural characteristics, a new segmented ship model with a U-shaped backbone was designed and fabricated in this paper. The novel U-shaped backbone can simultaneously simulate the vertical, horizontal, and torsional stiffnesses as well as the shear center of a full-scale container ship. Measurements of the vertical and horizontal bending moments of the ship model were achieved by assessing the corresponding bending strains of the U-shaped backbone. Integration of the shear flow method was developed for direct measurements of torsional moments. This method was validated through the calibration of the U-shaped backbone. On the basis of the new segmented ship model, vertical, horizontal, and torsional nonlinear springing tests were conducted successfully for the 20000 TEU container ship in the seakeeping basin of the CSSRC, and their characteristics and mechanisms were investigated. The test results reveal that nonlinear springing is a special case of high-frequency vibration that is induced by the harmonic excitation force. The resonance frequency component of the vertical bending moment of the midship is almost 2.5–4.5 times the corresponding wave frequency component when the ship experiences double-frequency vertical nonlinear springing at high speed under different wave headings. The severity of torsional nonlinear springing is not as pronounced as that of vertical nonlinear springing.

由弹簧引起的船舶结构疲劳强度问题正日益受到设计人员的关注。为了更精确地研究具有大开口结构特征的超大型集装箱船的非线性弹跳问题，本文设计并制作了一种具有 U 型骨架的新型分段船模。新型 U 型骨架可同时模拟全尺寸集装箱船的垂直、水平和扭转刚度以及剪切中心。通过评估 U 型骨架的相应弯曲应力，测量了船舶模型的垂直和水平弯矩。为直接测量扭转力矩，开发了剪切流集成方法。通过对 U 型主骨架的校准验证了这一方法。在新的分段船舶模型的基础上，在中国船舶重工集团公司的适航水池中成功进行了 20000 TEU 集装箱船的垂直、水平和扭转非线性弹跳试验，并研究了其特性和机理。试验结果表明，非线性弹振是谐波激振力引起的高频振动的一种特殊情况。当船舶在不同波头下高速行驶时，舯部垂直弯矩的共振频率分量几乎是相应波频分量的 2.5-4.5 倍。扭转非线性弹簧的严重程度不如垂直非线性弹簧明显。

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引用次数: 0

Numerical assessment of marine hose load response during reeling and free-hanging operations under Ocean waves 对海洋波浪下卷绕和自由悬挂作业期间的海洋软管负载响应进行数值评估

IF 4 2区工程技术 Q1 ENGINEERING, CIVIL

Marine Structures

Pub Date : 2024-10-02 DOI: 10.1016/j.marstruc.2024.103698

Chiemela Victor Amaechi , Ahmed Reda , Mohamed A. Shahin , Charles Agbomerie Odijie , Salmia Binti Beddu , Daud bin Mohamad , Agusril Syamsir , Idris Ahmed Ja'e , Xuanze Ju

In recent times, the need for sustainable fluid transfer has necessitated the application of bonded hoses and composite risers. It has been considered increasingly within the marine-offshore industry, with advances in loading/offloading operations, and newer offshore platforms. This paper presents a reeling study under different operational and environmental conditions. In this study, finite element modelling (FEM) was used for the design of marine bonded reeling hoses, and two wave spectra were applied to two reeling hose operations. The design assessed the load response of the marine bonded hoses during two different operations, including free-hanging (static) and reeling (dynamic/loading), and assessments were made for reinforced and mainline hoses. The findings aid an understanding on the load response, tension profiles, stress profiles, strain distribution and hose curvature of marine reeling hoses. The study showed different fluid contents affect the performance of the hose differently parametrically. It justifies the use of design specifications for reeling hose under the operation modes for marine application. The recommendations obtained from this study can assist in developing standards and guidance for use by marine hose designers and manufacturers.

近来，出于对可持续流体输送的需求，有必要应用粘合软管和复合立管。随着装载/卸载操作的进步和海上平台的更新，海洋-近海工业越来越多地考虑到了这一点。本文介绍了在不同操作和环境条件下的卷取研究。在这项研究中，有限元建模（FEM）被用于设计海洋粘合卷收软管，两种波谱被应用于两种卷收软管操作。设计评估了船用粘合软管在两种不同操作过程中的负载响应，包括自由悬挂（静态）和收卷（动态/负载），并对加固软管和主线软管进行了评估。研究结果有助于了解船用卷盘软管的负载响应、拉力曲线、应力曲线、应变分布和软管曲率。研究表明，不同的流体含量对软管性能的参数影响不同。这证明在船舶应用的操作模式下使用卷盘软管的设计规范是合理的。这项研究提出的建议有助于制定标准和指南，供船用软管设计人员和制造商使用。

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引用次数: 0