Marine Structures最新文献

{"title":"Large static deformation analysis of thin cylindrical shells with different moduli in tension and compression: An application in pressure hulls","authors":"Xiao-Ting He ,&nbsp;Jun-Song Ran ,&nbsp;Xin Wang ,&nbsp;Jun-Yi Sun","doi":"10.1016/j.marstruc.2025.103859","DOIUrl":"10.1016/j.marstruc.2025.103859","url":null,"abstract":"<div><div>Bimodular materials have different moduli of elasticity in tension and compression. In existing studies, the bimodular effect of materials is rarely considered due to the complexity of the analysis. This paper presents a theoretical study of large static deformation problems of thin circumferentially-closed cylindrical shells with bimodular effect in an underwater environment. First, the geometrical and physical equations of large axisymmetric deformation of bimodular thin cylindrical shells are established, and the total strain energy of the cylindrical shell is obtained. Based on variation principle, the Ritz method is used for the obtainment of the important relationship between external pressure and deformation. The numerical simulation based on ABAQUS also validates the analytical relation. As an application example, the underwater pressure hulls considering the bimodular effect and large deformation is analyzed. Results show that the bimodular effect change the stiffness of shells to some extent, thus leading to changes in deformation. The cylindrical shell is more sensitive to the bimodular effect at higher loads. In addition, the change of radius-to-thickness ratios of shells will strengthen bimodular effect on deformation while the change of length-to-radius ratios will influence the bending configurations of shells. In the design of pressure hulls, considering the bimodular effect will play a positive role in materials saving.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103859"},"PeriodicalIF":4.0,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144195203","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}

{"title":"Model tests of a stiffness-similar jack-up, Part 1: Model design, fabrication and structural pre-tests","authors":"M. Cai,&nbsp;S. Zhang,&nbsp;C. Zhang,&nbsp;W.K. Chen,&nbsp;M. Yu,&nbsp;C.K. Yeo,&nbsp;H.J. Soo,&nbsp;J. Cao,&nbsp;Y.Z. Law,&nbsp;B.V.E. How,&nbsp;H. Santo,&nbsp;A.R. Magee,&nbsp;M. Si","doi":"10.1016/j.marstruc.2025.103846","DOIUrl":"10.1016/j.marstruc.2025.103846","url":null,"abstract":"<div><div>This paper forms Part 1 of a paper series on jack-up model tests describing model design, fabrication and an extensive set of structural pre-tests. The model tests were aimed to provide high quality data-sets for the development of structural digital twin, therefore realistic and representative model of a jack-up platform at model-scale would be essential. In this regard, a generic jack-up model at 1:30 scale was designed such that the dynamic behaviour at full-scale was representative of actual jack-ups as reported in the literature. The main novelty was the use of Polycarbonate (PC) material to construct the leg structure, such that stiffness-similarity at model-scale could be achieved, both in terms of bending and axial rigidity. The benefits are two-fold. First, this allows direct strain/stress measurements along the legs to obtain axial member forces. Second, foundation fixity and leg-to-hull fixity at model-scale can also be representatively modelled such that the measured boundary forces were meaningful. The design and structural pre-tests of the key components of the jack-up model, which included the legs, spudcan, leg-to-hull connection, hull and cantilever, are thoroughly described in this paper. In general, good linear behaviours were observed, although small non-linear behaviour was noted for the spudcan module at lower loading amplitude. Additional pre-tests of the assembled jack-up model were also conducted prior to the start of model tests, and similar observations were drawn. A numerical Finite Element model of the jack-up was set up using ABAQUS, and in general, good agreement was achieved between measurements and numerical simulations for the boundary forces, moments and strains, as well as the overall dynamic characteristics. The numerical model could form the basis for development of structural digital twin tapping on the model test results for validation and proof-of-concept.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103846"},"PeriodicalIF":4.0,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144184598","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}

{"title":"Numerical study for elastic floating structures coupled with nonlinear mooring system in irregular waves, including a multi-unit floating offshore wind turbine platform","authors":"HeonYong Kang","doi":"10.1016/j.marstruc.2025.103848","DOIUrl":"10.1016/j.marstruc.2025.103848","url":null,"abstract":"<div><div>To understand interactions of an elastic floating structure with nonlinear mooring dynamics and multiple wind turbines dynamics especially in irregular waves, the elastic mode expansion of Cummins’ equation for an elastic structure in irregular waves is strongly coupled with nonlinear rod element method for the nonlinear mooring lines through Jacobian matrix formed in a time-domain predictor and corrector solver up to the second order. The multiple wind turbines dynamics is resolved by load mapping of stress resultants at wind turbines into the hosting structure. Three numerical studies are presented to investigate linear elastic mode resonance interacting with both of nonlinear mooring excitation and higher elastic modes with the second order irregular waves, nonlinear elastic mode resonance with higher order harmonic excitation from various mooring lines, and three-dimensional elastic deformation interacting with multiple wind turbines dynamics in combination with nonlinear mooring excitation in irregular wave loads. The numerical study further identifies three-dimensional deformation can have substantial interactions with multiple wind turbine dynamics, influenced by outstanding rigid modes, while analogous symmetry in modes imposes strong coupling between elastic and rigid modes as well. Moreover, the relative configuration between mode shapes, mooring, and wind turbines can determine the coupled hydroelastic responses.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103848"},"PeriodicalIF":4.0,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144147180","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}

{"title":"A review on fluid-sediment and foundation-sediment coupling mechanisms and anti-scour countermeasures","authors":"Fei Sha,&nbsp;Jingze Xu,&nbsp;Shijiu Gu,&nbsp;Yulong Dong,&nbsp;Wenwen Xiao","doi":"10.1016/j.marstruc.2025.103843","DOIUrl":"10.1016/j.marstruc.2025.103843","url":null,"abstract":"<div><div>Offshore wind turbines (OWTs) have development prospects in the world energy supply system, and the local scour of the foundation of such turbines is an issue that may hinder their normal operation. Based on existing research, local scour characteristics based on fluid-sediment coupling are presented. At the individual soil particles or groups of particles level, the initiation mechanism of foundation scour is explained based on the force equilibrium of seabed particles, whereas at the scour hole level, the shapes and maximum scour depths are considered. Second, the local scour effects based on foundation-seabed coupling are discussed in terms of the lateral bearing capacity, p-y curve, and natural frequency. The study of fluid-sediment and foundation-sediment coupling mechanisms can clarify the protection mechanism of scour protection measures as well as the enhancement of protection. From the perspective of foundation scour control, different scour monitoring methods are analysed. The effects of different types of scour protection are also emphasised. Finally, the current problems and future research directions are presented. This paper provides insights into reducing the occurrence of the scour phenomenon, realising prevention and control of local foundation scour, and ensuring the normal and safe operation of OWTs.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103843"},"PeriodicalIF":4.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144147179","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}

{"title":"Dynamic response and performance of subsea sandwich pipelines with various interlayers subjected to underwater collision","authors":"Hong Lin ,&nbsp;Longcheng Wei ,&nbsp;Hao Xu ,&nbsp;Hassan Karampour ,&nbsp;Mahmoud Alrsai ,&nbsp;Qi Fan ,&nbsp;Lei Yang","doi":"10.1016/j.marstruc.2025.103853","DOIUrl":"10.1016/j.marstruc.2025.103853","url":null,"abstract":"<div><div>Compared to single-layer pipelines, sandwich pipelines exhibit superior resistance to accidental collisions caused by falling objects. However, previous research has rarely examined sandwich pipelines with different interlayer materials under underwater collisions. This study developed an Arbitrary Lagrangian-Eulerian (ALE) based numerical model to predict the behavior of the sandwich pipe when subjected to complex underwater collision scenarios, considering the fluid-structure interaction (FSI) effects. Subsequently, comparative simulations were performed using the Lagrange method to evaluate its feasibility and accuracy. The results indicate a good agreement between the ALE and Lagrange models. A sensitivity analysis was conducted based on the Lagrange collision model, and investigated the effect of collision velocity, collision angle, seabed properties and interlayer medium on the responses of the sandwich pipeline including deformation, stress, and energy properties. It is concluded that increasing the collision angle, decreasing the collision velocity, and enhancing the seabed stiffness reduce pipeline damage. The inner pipe deformation was more sensitive to the density of the interlayer foam than the outer pipe. Additionally, the water-filled interlayer exhibited superior resistance to collision loads compared to the air-filled interlayer.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103853"},"PeriodicalIF":4.0,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135143","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}

{"title":"Ultimate strength of sandwich elliptical pressure hulls: experimental, numerical and analytical investigations","authors":"Yinhui Tang ,&nbsp;Jian Zhang ,&nbsp;Huifeng Jiao ,&nbsp;Yunsen Hu ,&nbsp;Xiaozhi Hu","doi":"10.1016/j.marstruc.2025.103855","DOIUrl":"10.1016/j.marstruc.2025.103855","url":null,"abstract":"<div><div>This study investigates the buckling resistance of sandwich elliptical pressure hulls using experimental, numerical, and analytical methods. The hull, composed of two thin stainless steel faces bonded to a resin core, was fabricated through shell hydroforming. Geometric and thickness measurements confirmed manufacturing accuracy, and hydrostatic testing was performed to evaluate its structural performance. Nonlinear finite-element analysis (FEA) was used to examine the buckling mechanisms and ultimate strength of the hull. The results reveal that the sandwich structure significantly enhances ultimate strength and stability compared to single-layer elliptical pressure hulls. Specifically, the resin core functions as a barrier and stabilizes the structure by redistributing stresses between the external steel faces, which act as the primary load-bearing components. A semi-analytical equation was also developed and validated to predict the ultimate strength of the sandwich hull under hydrostatic conditions, providing a useful tool for structural design.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103855"},"PeriodicalIF":4.0,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114939","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}

{"title":"Probabilistic prediction of operable sea states with a random forest ensemble","authors":"Øystein Døskeland ,&nbsp;Svein Sævik ,&nbsp;Zhen Gao ,&nbsp;Petter Moen","doi":"10.1016/j.marstruc.2025.103850","DOIUrl":"10.1016/j.marstruc.2025.103850","url":null,"abstract":"<div><div>A Probabilistic Sea State Classification method (PSSC) is proposed to determine the operability of sea states from the forecasted wind and swell sea parameters. Unlike similar models, the proposed method produces an ensemble of possible outcomes from a random forest model, enabling a probabilistic assessment of operability that accounts for the model’s predictive error, the forecast uncertainty, and the random variability in the wave loads. The model was tested through a case study, considering crane wire loads during the subsea deployment of a suction anchor, comparing it against benchmark decisions based on the true sea state and conventional decisions based on the forecasted total wave parameters. Unlike conventional methods, the PSSC Model performed consistently across seasons with varying wave characteristics. Applied to an Ultimate Limit State (ULS) criterion, the long-term distribution of load exceedance over the five-year test set closely matched the benchmark distribution at the target 10^–1 level. However, incorporating forecast uncertainty and modeling errors in the probabilistic assessment altered the distribution of the extreme loads, such that the benchmark was exceeded at the 10^–4 probability level. More work is needed for practical application, establishing a revised load factor, or considering detailed reliability analyses using Monte Carlo simulations. The latter requires extensive training since the model cannot extrapolate beyond known data points.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103850"},"PeriodicalIF":4.0,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114940","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}

{"title":"Stress analysis and frictional behavior of helical power core components in marine dynamic cables under axial tension and bending loads","authors":"Gongsai Huang ,&nbsp;Chongchong Guo ,&nbsp;Hongjiang Li ,&nbsp;Wenhua Wu","doi":"10.1016/j.marstruc.2025.103854","DOIUrl":"10.1016/j.marstruc.2025.103854","url":null,"abstract":"<div><div>As the development of offshore wind energy continues increasing, the utilization of dynamic cables becomes crucial. Helical power core components are essential functional elements in marine dynamic cables, and understanding the mechanical behavior of these spiral structures under complex external loads has garnered significant attention. This study introduces a comprehensive stress analysis model for helical power core components in dynamic cables subjected to axial tension and bending loads. Unlike previous simplified models, the proposed approach fully accounts for the double-helix structure in the conductor configuration. By introducing Darboux vectors, which encompass two curvatures and one twist, the mechanical response models for both single-helix and double-helix conductor wires under combined tension and bending loads are developed. The study further delves into the interactions between local frictional contact and the geometric characteristics of the helical structure, leading to the formulation of analytical models for contact stresses in helical components. Additionally, a multi-layer pressure transmission model for the helical power core is proposed based on the force action-reaction principle. To account for frictional forces, Coulomb’s friction law is integrated into the model, and an iterative solution procedure is provided to obtain friction-slip results. The theoretical model is verified using finite element (FE) simulations and existing experimental data, specifically applied to a high-voltage direct current (HVDC) cable. The results demonstrate the accuracy of the model in predicting cross-sectional stresses under nonlinear combined tension and bending moments. This work offers valuable technical support for the analysis and design of marine dynamic cables under complex loading conditions, contributing to the optimization of their mechanical performance.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103854"},"PeriodicalIF":4.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107774","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}

{"title":"Low frequency vibration reduction of CFRP raft frame based on local resonance","authors":"Jinguang Zhang ,&nbsp;Kai Fu ,&nbsp;Jun Rao ,&nbsp;Xu Xia ,&nbsp;Yukuan Dou ,&nbsp;Xianglong Wen","doi":"10.1016/j.marstruc.2025.103851","DOIUrl":"10.1016/j.marstruc.2025.103851","url":null,"abstract":"<div><div>As the demand for enhanced ship stealth performance continued to grow, the need for effective vibration isolation in the floating raft frame system, particularly within the low-frequency range, was increased. The raft frame played a critical role in determining the overall vibration-reduction performance. To improve the low-frequency vibration reduction, this paper incorporated the low-frequency elastic wave modulation characteristics of local resonance and the high damping properties of Carbon Fiber Reinforced Plastics (CFRP) into the raft frame, investigating their vibration characteristics via a test platform. Different oscillator distributions and masses were applied to the CFRP raft frame to study their effects on vibration behavior, with measurements taken using the B&amp;K test system. The results revealed that the addition of oscillators lowered the initial vibration attenuation frequency and increased the maximum vibration attenuation from 48.9 dB to 103.2 dB. Optimal vibration reduction was achieved by placing the oscillators at the support position for low-frequency attenuation and at the center position for high-frequency attenuation. This spatial distribution strategy demonstrated agreement with simulation predictions. In conclusion, integrating the low-frequency modulation characteristics of local resonance into the CFRP raft frame significantly enhanced its vibration-reduction performance.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103851"},"PeriodicalIF":4.0,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144114937","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}

{"title":"Thermal instability behaviors of the subsea confined FGP-GPLs polyhedral pipeline under a temperature-rising field","authors":"Qian Zhang ,&nbsp;Meiling Shen ,&nbsp;Zhaochao Li","doi":"10.1016/j.marstruc.2025.103852","DOIUrl":"10.1016/j.marstruc.2025.103852","url":null,"abstract":"<div><div>Subsea pipelines are usually heated to reduce the viscosity and improve transportation efficiency during the transportation of crude oil. However, subsea pipelines may buckle under the rise of the thermal field. Therefore, this study employs a novel functionally graded porous (FGP) metal reinforced by graphene platelets (GPLs) and polyhedral profile to enhance the thermal stability of the encased subsea pipelines. The distribution of the pores and GPLs in the cross-section of the pipelines is determined by the Halpin-Tsai micromechanics theory and Gaussian random field. The geometric parameters of the polyhedral profile are defined. Geometric nonlinearity is considered. A radial displacement function is introduced to describe the deformation of pipelines. Based on the theory of thin-walled shells and the energy method, the temperature-displacement equilibrium paths may be traced, and the minimum and maximum temperature variation also may be obtained. Subsequently, comparative studies are conducted with the results of the other available studies. Good accordance indicates the present study is efficient and accurate. An improvement factor is quantified to discuss the effect of a polyhedral profile on thermal stability compared to a circular one. Finally, parametric evaluations are highlighted by analyzing the effects of pores, the weight fraction of the GPLs, polyhedral profile on the thermal buckling.</div></div>","PeriodicalId":49879,"journal":{"name":"Marine Structures","volume":"103 ","pages":"Article 103852"},"PeriodicalIF":4.0,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107866","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}