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Assessment of operational limits: Effects of uncertainties in sea state description Mar. Struct. (IF 2.708) Pub Date : 2021-02-25 Lin Li; Sverre Haver; Nikita Berlin
For operations dominated by waves, operational limits are normally expressed in terms of allowable sea state parameters, such as the significant wave height (Hs) and spectral peak period (Tp). The allowable sea states need to be assessed in the planning phase of the operations. Different sources of uncertainties (including weather forecasts, wave spectral model and numerical models) should be accounted
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Structural damage identification by a cross modal energy sensitivity based mode subset selection strategy Mar. Struct. (IF 2.708) Pub Date : 2021-02-24 Mingqiang Xu; Shuqing Wang; Yufeng Jiang
This paper presents a strategy specialized for modal energy (ME) based methods, including modal strain energy (MSE) and modal kinetic energy (MKE), to select the best mode subset prior to damage identification. The damages due to the changes in stiffness and mass of structural members are both considered. In order to apply the proposed scheme to a more general situation, the cross modal energy (CME)
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Buckle propagation of damaged SHCC sandwich pipes: Experimental tests and numerical simulation Mar. Struct. (IF 2.708) Pub Date : 2021-02-20 Guangming Fu; Segen F. Estefen; M.I. Lourenço; Jiankun Yang; Claudio M. Paz; Menglan Duan
Sandwich pipe (SP) combining high-strength performance and thermal insulation has been considered an effective solution for oil and gas transportation in ultra-deepwater. Strain hardening cementitious composite (SHCC) is well known for its capacity to withstand both tensile load and external hydrostatic pressure. The sandwich pipe considered in the research is constituted of concentric steel pipes
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Modeling dynamic cable–sheave contact and detachment during towing operations Mar. Struct. (IF 2.708) Pub Date : 2021-02-17 Cassidy Westin; Rishad A. Irani
Cable–sheave systems are commonly used on marine vessels for lifting and towing applications. As a result of the motion of the vessel, the cable can detach from the surface of the sheave. This paper presents a finite element model of a towed cable system based on the Absolute Nodal Coordinate Formulation. The model includes the interaction of the cable with the sheave surface in order to examine variations
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Dynamic response of stiffened plate under internal blast: Experimental and numerical investigation Mar. Struct. (IF 2.708) Pub Date : 2021-02-12 Ying Li; Xianben Ren; Tian Zhao; Dengbao Xiao; Kai Liu; Daining Fang
Stiffened plates are the basic units of ships, aircraft and other structures. The purpose of this paper is to investigate the dynamic response of stiffened plates under internal blast loading. A combined experimental and numerical investigation was carried out on the cabin structures with unstiffened, single-stiffened and double-stiffened plates. The characteristics of internal blast wave, the effects
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Environmental lumping for efficient fatigue assessment of large-diameter monopile wind turbines Mar. Struct. (IF 2.708) Pub Date : 2021-02-11 George Katsikogiannis; Stian Høegh Sørum; Erin E. Bachynski; Jørgen Amdahl
Fatigue damage is one of the governing factors for the design of offshore wind turbines. However, the full fatigue assessment is a time-consuming task. During the design process, the site-specific environmental parameters are usually condensed by a lumping process to reduce the computational effort. Preservation of fatigue damage during lumping requires an accurate consideration of the met-ocean climate
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Fitness-for-purpose assessment of cracked offshore wind turbine monopile Mar. Struct. (IF 2.708) Pub Date : 2021-02-10 A. Fajuyigbe; F. Brennan
In this paper, the procedure for flaw acceptability assessment is examined through a case study of a semi-elliptical surface crack in an offshore monopile as it grows till it forms a through thickness crack. Using the procedure prescribed in an industrial standard (BS 7910), the fracture ratio, Kr is shown to increase monotonically with increasing crack depth. The load ratio, Lr, is initially insensitive
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Mechanical behavior of metallic strip flexible pipes during reeling operation Mar. Struct. (IF 2.708) Pub Date : 2021-02-05 Yuxin Xu; Pan Fang; Yong Bai
Metallic strip flexible pipes (MSFP), a relatively new style of unbonded flexible pipes, are considered as an attractive alternative to traditional submarine pipes. During its reeling operation, it will inevitably confront various complicated loads, which may affect the integrity and safety of MSFP's utilization. In this paper, the tension-extension and moment-curvature relation of MSFP were obtained
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Bend stiffener linear viscoelastic thermo-mechanical analysis, Part II: Numerical solution and case study Mar. Struct. (IF 2.708) Pub Date : 2021-02-05 Aynor J. Ariza Gomez; Marcelo Caire; Luis Carlos Absalon Rojas Torres; Murilo Augusto Vaz
The viscoelastic energy dissipated by the bend stiffener when subjected to cyclic loading increases the polyurethane temperature and may affect the system curvature distribution in a coupled manner. The steady-state thermo-mechanical mathematical formulation and material experimental characterization has been presented in a companion paper (Part I). In this work (Part II), the rate of viscoelastic
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Foundation damping for monopile supported offshore wind turbines: A review Mar. Struct. (IF 2.708) Pub Date : 2021-02-01 Abdollah Malekjafarian; Soroosh Jalilvand; Paul Doherty; David Igoe
Today, an important challenge for offshore wind energy is to design efficient and reliable offshore wind turbines (OWTs). The overall damping of OWTs plays an important role in the design process as it limits the amplitude of the OWT dynamic response at frequencies near resonance. Therefore, an accurate estimation of OWTs damping is necessary for the efficient design of these systems. The foundation
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Potential of a repair system for grouted connections in offshore structures: Development and experimental verification Mar. Struct. (IF 2.708) Pub Date : 2021-02-01 Götz Hüsken; Md Shamsuddoha; Stephan Pirskawetz; Detlef Hofmann; Matthias Baeßler; Hans-Carsten Kühne
Grouted connections are intensively used in offshore rigs, platforms as well as jacket and monopile offshore wind turbine structures. Being located in remote offshore conditions, these connections can experience considerable adverse loading during their lifetimes. Degradation was reported inside similar connections, which were installed in the last three decades. Grouting in the offshore sites may
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Passive control of jacket–type offshore wind turbine vibrations by single and multiple tuned mass dampers Mar. Struct. (IF 2.708) Pub Date : 2021-02-01 Da Chen; Shanshan Huang; Chenggeng Huang; Ruiwen Liu; Feng Ouyang
Vibration control is gaining focuses in the field of offshore wind turbines (OWTs) in recent years as the turbine tower becomes taller and more slender. Although a number of research works have been carried out to control the OWT vibrations, using tuned mass damper (TMD) and multiple tuned mass dampers (MTMDs) to control the jacket–type OWT vibrations is rarely reported, especially for the MTMDs, of
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Bend stiffener linear viscoelastic thermo-mechanical analysis. Part I — Experimental characterization and mathematical formulation Mar. Struct. (IF 2.708) Pub Date : 2021-01-30 Aynor J. Ariza Gomez; Marcelo Caire; Luis Carlos Absalon Rojas Torres; Murilo Augusto Vaz
Bend stiffeners are subjected to cyclic loading during offshore operation or when subjected to a controlled full-scale qualification test. Due to the viscoelastic nature of the polyurethane, energy is dissipated within the material volume and the structure may experience a temperature increase, a phenomenon known as self-heating. The top connection is a flexible riser critical region in terms of fatigue
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Local joint flexibility of tubular T/Y-joints retrofitted with GFRP under in-plane bending moment Mar. Struct. (IF 2.708) Pub Date : 2021-01-25 Hossein Nassiraei; Pooya Rezadoost
In the present paper, the Local Joint Flexibility (LJF) of tubular T/Y-joints retrofitted with Glass Fiber Reinforced Polymer (GFRP) under IPB moment is studied and discussed. For this aim, a finite element (FE) model was generated and verified with the results of available experimental data and parametric formulas. Afterward, a set of 158 finite element (FE) models was created to evaluate the efficacy
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Real-time estimation of riser's deformed shape using inclinometers and Extended Kalman Filter Mar. Struct. (IF 2.708) Pub Date : 2021-01-22 HanSung Kim; Chungkuk Jin; MooHyun Kim
The real-time monitoring of underwater risers, cables, and mooring lines by multiple sensors is in great demand but still very challenging. In this study, a new real-time riser monitoring method based on an Extended Kalman Filter (EKF) is proposed. It estimates the overall shape of riser in real-time utilizing the measured signals from multiple bi-axial (inclination and heading) inclinometers along
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Development of interlink wear estimation method for mooring chain of floating structures: Validation and new approach using three-dimensional contact response Mar. Struct. (IF 2.708) Pub Date : 2021-01-19 Takaaki Takeuchi; Tomoaki Utsunomiya; Koji Gotoh; Iku Sato
Long-term operation of mooring systems is one of the challenging issues of floating structures such as floating offshore wind turbines (FOWTs). For integrity assessment, fatigue and its affecting factors have generated considerable recent research interest as the occurrence of a large number of mooring chain failures at a high rate has been reported. By contrast, only few studies on the effect of nonuniform
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Extreme hawser tension assessment for FPSO vessel during offloading operation in Bohai bay Mar. Struct. (IF 2.708) Pub Date : 2021-01-15 Oleg Gaidai; Xiaosen Xu; Prasanta Sahoo; Renchuan Ye; Yong Cheng
The Floating Production Storage and Offloading Unit (FPSO) is an offshore vessel that produces and stores crude oil prior to tanker transport. Robust prediction of extreme hawser tensions during Floating Production Storage and Offloading (FPSO) operation is an important safety concern. Excessive hawser tension may occur during offloading operations, posing an operational risk. In this paper, AQWA has
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Thermomechanical performance of offshore topside steel structure exposed to localised fire conditions Mar. Struct. (IF 2.708) Pub Date : 2021-01-13 Miguel R. Manco; Murilo A. Vaz; Julio C.R. Cyrino; Alexandre Landesmann
This work reports the results of a numerical investigation aiming at assessing the structural safety of an actual offshore topside steel structure exposed to accidental localised fire conditions. Particularly, the paper explores the nonlinear thermomechanical and ultimate strength behaviours obtained by means of two fire approaches: sophisticated CFD (Computational Fluid Dynamics) and “LF-ESF” (Localised
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On the collapse of thick-walled pipes with corrosion defects under external pressure Mar. Struct. (IF 2.708) Pub Date : 2021-01-11 Shunfeng Gong; Libei Zhou; Xipeng Wang; Lin Yuan; Chengbin Liu
Corrosion defect is considered to be one of the major critical damages of subsea pipelines, which can result in a considerable loss in the collapse capacity of thick-walled pipes in deep waters. In this paper, collapse experiments on 13 small-scale seamless steel tubes with varying sizes of elliptical and rectangular corrosion defects were carried out in a sealed hyperbaric chamber. The collapse pressure
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Sea state estimation based on vessel motion responses: Improved smoothness and robustness using Bézier surface and L1 optimization Mar. Struct. (IF 2.708) Pub Date : 2021-01-07 Zhengru Ren; Xu Han; Amrit Shankar Verma; Johann Alexander Dirdal; Roger Skjetne
Floating structures oscillate in waves, where these wave-induced motions may be critical for various marine operations. An important consideration is thereby given to the sea states at the planning and operating stages for an offshore project. The most important information extracted from a sea state is the directional wave spectrum, indicating wave direction, significant wave height, and wave spectrum
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A theoretical calculation method of irregular bridge span pontoon connected by elastic hinges Mar. Struct. (IF 2.708) Pub Date : 2021-01-07 Heng Huang; Xujun Chen; Junyi Liu; Qifei Chen
In this paper, a theoretical calculation method that can be generally applied to responses analysis of irregular bridge span pontoon connected by elastic hinges was proposed based on the elastic foundation beam theory. This method can solve the displacements, rotation angles, bending moments and shear forces of pontoon bridge under vertical static loads. By comparing with the experimental and numerical
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Vibration-assisted decommissioning of a slip joint: Application to an offshore wind turbine Mar. Struct. (IF 2.708) Pub Date : 2021-01-06 Alessandro Cabboi; Thijs Kamphuis; Evert van Veldhuizen; Maxim Segeren; Hayo Hendrikse
An alternative option to the traditional grouted joint for wind turbines is a direct steel-to-steel connection, also known as slip joint. In a recently published work, a proof of concept of a vibration-assisted installation and decommissioning technique of a slip joint was illustrated. Leveraging on the obtained results, the current study shows for the first time a decommissioning campaign carried
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Probabilistic time series prediction of ship structural response using Volterra series Mar. Struct. (IF 2.708) Pub Date : 2021-01-01 Jae-Hyeon Son; Yooil Kim
This study targets to develop a computational procedure to predict the structural response of a ship voyaging through irregular seaways taking into account the relevant uncertainties from probability perspective. To achieve the goal, ship structural response under random wave excitation was assumed to be linear one and represented by linear Volterra series, which is expanded by linear combination of
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Effects of various fairlead-connection parameters on chain-mooring OPB-induced failure Mar. Struct. (IF 2.708) Pub Date : 2020-12-30 Woo Chul Chung; MooHyun Kim
In this paper, the effects of underwater-chain-stopper (UCS) bearing friction at fairlead connection and time-varying interlink EI (bending stiffness) at the UCS exit on the OPB-fatigue-induced chain failure are investigated. To demonstrate their effects through numerical simulations, three different approaches, such as only considering time-varying EI, considering both time-varying EI and fairlead
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Second-order wave run-up on a vertical cylinder adjacent to a plane wall based on the application of quadratic transfer function in bi-directional waves Mar. Struct. (IF 2.708) Pub Date : 2020-12-29 Peiwen Cong; Bin Teng; Wei Bai
A numerical model was developed in this study to simulate the wave diffraction caused by an arbitrarily shaped structure in the presence of bi-directional incident waves based on a higher-order boundary element method (HOBEM). Based on the developed model, the wave elevation quadratic transfer function (QTF) in bi-directional waves, which is defined as the second-order wave elevation caused by two
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An expeditious algebraic formulation to the buckling critical load of risers under dynamic compression Mar. Struct. (IF 2.708) Pub Date : 2020-12-29 Rodrigo M. Amarante; André L.C. Fujarra
Dynamic compression of risers can play an important role in the structural stability of submerged pipes in catenary-like configuration. In this paper, the analytical formulation for the buckling critical load, developed in the early 2000's, is revisited and extended to cover a wider range of practical cases. A purely algebraic expression for the critical load is provided, eliminating the original formulation
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Stochastic geometric imperfections of plate elements and their impact on the probabilistic ultimate strength assessment of plates and hull-girders Mar. Struct. (IF 2.708) Pub Date : 2020-12-29 Dimitris G. Georgiadis; Manolis S. Samuelides
The present paper proposes a novel approach for the representation of the imperfect plate geometry of ships structures and assess its impact on the probabilistic ultimate strength of plates and hull-girders. The description of the imperfect geometry is basically implemented using the theory of random fields. Evidence for the selection and robustness of the proposed model is documented from literature
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Joints behaviour of through steel beam to composite column connection: Experimental study Mar. Struct. (IF 2.708) Pub Date : 2020-12-29 Bashar A. Shehab; Talha Ekmekyapar
The objective of this study is to categorize the failure modes; moment and rotation capacities; ductility; stiffness; joint classification; strain behaviour; and load transfer mechanism of steel beam through CFST column connections. Eight one-third scale composite joints were tested under static load up to failure. The key parameters comprise two ηStrength ratios; the effect of beam flange and web
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Ship motion-sloshing interaction using a field method Mar. Struct. (IF 2.708) Pub Date : 2020-12-29 Wenjing Lyu; Ould el Moctar; Thomas E. Schellin
Even in relatively calm waters, low amplitude wave-induced motions of an LNG carrier may induce large amplitude liquid sloshing inside the ship's partially filled tanks, and the interaction between ship motions and sloshing may affect the ship's seekeeping properties. A computational procedure, here referred to as the RANS-RANS method, was developed to account for this interaction, and this method
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The measurement accuracy of instrumented ship structures under local ice loads using strain gauges Mar. Struct. (IF 2.708) Pub Date : 2020-12-18 Angelo Mario Böhm; Rüdiger Ulrich Franz von Bock und Polach; Hauke Herrnring; Sören Ehlers
Strain gauges are commonly used for the instrumentation of ship structures to measure ice loads on the basis of shear strain differences. Finite Element Analysis (FEA) is used to determine the load–strain relation of the instrumented area by calculating an Influence Coefficient Matrix (ICM). However, the accuracy of the measurement method and the influence of the load location and load length on the
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Ultimate load analysis of a 10 MW offshore monopile wind turbine incorporating fully nonlinear irregular wave kinematics Mar. Struct. (IF 2.708) Pub Date : 2020-12-19 Shaofeng Wang; Torben Juul Larsen; Henrik Bredmose
Loads from storm waves can in some cases be dimensioning for offshore wind turbine substructures. Accurate determination of nonlinear wave loads is therefore important for a safe, yet economic design. In this paper, the fully nonlinear waves, realized by a fully nonlinear potential wave solver OceanWave3D, are incorporated into coupled aero-servo-hydro-elastic simulations for a reduced set of wave-sensitive
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Stress concentration factors in tubular T/Y-connections reinforced with FRP under in-plane bending load Mar. Struct. (IF 2.708) Pub Date : 2020-12-10 Hossein Nassiraei; Pooya Rezadoost
Stress concentration factors (SCFs) in steel tubular T/Y-connections strengthened with fiber reinforced polymer (FRP) are investigated. In the first step, a finite element (FE) model was developed and verified using data of several available experimental tests and empirical formulas. After that, 134 FE models of T/Y-joints with and without FRP were created and analyzed under in-plane bending (IPB) load
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Finite element study on circular armour wire lateral buckling in umbilicals Mar. Struct. (IF 2.708) Pub Date : 2020-12-10 Xiaotian Li; Murilo Augusto Vaz
The present paper addresses the circular armour wire lateral buckling in umbilicals. An asymmetric non-linear finite element model is developed to analyze a single armour wire subjected to combined constant axial compression and uniform cyclic curvatures. A parametric case study is performed for an armour wire from a nine-hose umbilical cable, where the armour wire pitch number, applied axial compressive
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Estimation of natural frequencies and damping using dynamic field data from an offshore wind turbine Mar. Struct. (IF 2.708) Pub Date : 2020-12-09 Karin Norén-Cosgriff; Amir M. Kaynia
The dynamic characteristics of offshore wind turbines are heavily affected by environmental loads from wave and wind action and nonlinear soil behaviour. In the design of the monopile structures, the fatigue load due to wind and wave loading is one of the most important problems to consider. Since the fatigue damage is sensitive to the foundation stiffness and damping, increasing the accuracy of analysis
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Imperfection study on lateral thermal buckling of subsea pipeline triggered by a distributed buoyancy section Mar. Struct. (IF 2.708) Pub Date : 2020-12-07 Zhenkui Wang; Yougang Tang; C. Guedes Soares
Controlled lateral buckling is triggered by distributed buoyancy section at predesigned sites to release the axial force induced by high temperature and high pressure in subsea pipelines. Due to the larger diameter and smaller submerged weight of distributed buoyancy section, compared to the normal pipe section, imperfections are more easily introduced at the location of distributed buoyancy section
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Hysteretic damping model for laterally loaded piles Mar. Struct. (IF 2.708) Pub Date : 2020-11-25 Youhu Zhang; Kristoffer Knoph Aamodt; Amir M. Kaynia
Fatigue assessment is a critical design aspect for many offshore structures. Soil-foundation interaction has a direct impact on the system dynamic response of these structures. While the stiffness of the soil-foundation interaction influences the system's natural frequency, the damping influences the amplification of the structural response to environmental excitations. This paper presents a simplified
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Low-cycle fatigue assessment of offshore mooring chains under service loading Mar. Struct. (IF 2.708) Pub Date : 2020-11-25 G.M. Gemilang; P.A.S. Reed; A.J. Sobey
The integrity of mooring chains is essential to the safety of a range of offshore platforms. However, mooring line failures are occurring earlier than their design lives, with a high number of these failures occurring due to fatigue. Early in the fatigue life of the component fatigue initiation processes occur, where the fatigue hotspot is sensitive to the mean load and there is plastic strain accumulation
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Application of embedded fibre Bragg grating sensors for structural health monitoring of complex composite structures for marine applications Mar. Struct. (IF 2.708) Pub Date : 2020-11-24 Magdalena Mieloszyk; Katarzyna Majewska; Wieslaw Ostachowicz
Fibre reinforced polymer (FRP) materials are recently widely applied in the marine industry. The high popularity of composites and safety requirements results in the development of Structural Health Monitoring (SHM) systems. One of the sensors types that can be permanently integrated with a composite structure and used as a part of SHM system are fibre Bragg grating (FBG) sensors. Among FBG sensors
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Flow around two elastically-mounted cylinders with different diameters in tandem and staggered configurations in the subcritical Reynolds number regime Mar. Struct. (IF 2.708) Pub Date : 2020-11-21 Marek Jan Janocha; Muk Chen Ong; Per Richard Nystrøm; Zhenguo Tu; Geir Endal; Halvor Stokholm
Flow around two cylinders with different diameters undergoing Flow-Induced Vibrations (FIV) in the subcritical flow regime is investigated using two-dimensional Unsteady Reynolds Averaged Navier-Stokes (URANS) approach. Physical parameters of the system are chosen to represent the free spanning pipelines laid in proximity. The two cylinders are initially placed at various tandem and staggered positions
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Efficient methods to mitigate SCR-induced walking of short subsea flowlines Mar. Struct. (IF 2.708) Pub Date : 2020-11-20 I. Seyfipour; M.R. Bahaari; R. Mirghaderi
Steel catenary riser is a long-established option for subsea projects in deep-water regions. Sustained pulling force of steel catenary risers on subsea flowlines in combination with cyclic thermal load throughout the system lifetime may lead to progressive global axial displacement of subsea pipelines which has been termed as ‘walking’. One of the challenges in the deep-water industry is long-term
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A simplified method for holistic value of information computation for informed structural integrity management under uncertainty Mar. Struct. (IF 2.708) Pub Date : 2020-11-20 Guang Zou; Michael Havbro Faber; Arturo González; Kian Banisoleiman
Collecting structural information by inspection or monitoring is important means to reduce uncertainty and improve the qualities of maintenance decisions in structural integrity management. However, information collecting inevitably involves some costs. When information collecting brings added value and to what extent uncertainty reduction suffices are questions that are often not fully accounted for
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Chloride diffusion models for Type I and fly ash cement concrete exposed to field and laboratory conditions Mar. Struct. (IF 2.708) Pub Date : 2020-11-20 Khaled A. Alawi Al-Sodani; Mesfer Mohammad Al-Zahrani; Mohammed Maslehuddin; Omar S. Baghabra Al-Amoudi; Salah U. Al-Dulaijan
The exposure temperature significantly affects the diffusion of chloride ions in concrete, and, as such, it must be taken into consideration in the development of service-life prediction models for structures exposed to chloride-bearing environments. Most of the earlier studies have used cement paste to assess the effect of exposure temperature on chloride diffusion. In the reported study, chloride
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Plastic deformation of ship plate subjected to repeated patch loads at different locations - Elastoplastic numerical analysis and design equation Mar. Struct. (IF 2.708) Pub Date : 2020-11-20 Wei Cai; Ling Zhu; Fuhua Wang
Ship structures may be subjected to repeated random patch loads at different locations. Under these circumstances, ship plates will have large accumulated permanent deformations, which will result in some serious negative effects on their work and safety performance. Therefore, the elasto-plastic response of ship structure under repeated patch loads at different locations are studied by using finite
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Analysis of structural crashworthiness of double-hull ships in collision and grounding Mar. Struct. (IF 2.708) Pub Date : 2020-11-19 Bin Liu; R. Villavicencio; P. Terndrup Pedersen; C. Guedes Soares
A conceptual design framework for collision and grounding analysis is proposed to evaluate the crashworthiness of double-hull structures. This work attempts to simplify the input parameters needed for the analysis, which can be considered as a step towards a design-oriented procedure against collision and grounding. Four typical collision and grounding scenarios are considered: (1) side structure struck
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Through-wall yield ductile burst pressure of high-grade steel tube and casing with and without corroded defect Mar. Struct. (IF 2.708) Pub Date : 2020-11-19 Deng Kuanhai; Peng Yang; Liu Bing; Lin Yuanhua; Wang Jiandong
Service environment of tube and casing in deep and ultra-deep well is getting more and more complicated, and the internal pressure applied to tube and casing is higher, so that the high-grade steel tube and casing (HGTC) made of ductile material is widely used. Obviously, the calculation of ductile burst pressure for HGTC is one of the key factors in design and important to safe and efficient development
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On the Huse-Muren model for wake interaction with vertical offshore cylinders Mar. Struct. (IF 2.708) Pub Date : 2020-11-18 Jiangnan Lu; J.M. Niedzwecki
There are many offshore applications that incorporate vertical cylindrical-shaped structural elements such as marine risers, TLP tendons and near shore pier designs. A better understanding of complex wake flows on the drag dominated force predictions is very much of interest for offshore design problems. This study investigates the Huse-Muren analytical wake model, whose mathematical formulation was
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On maximum forces exerted by floating ice on a structure due to constrained thermal expansion of ice Mar. Struct. (IF 2.708) Pub Date : 2020-11-06 Ryszard Staroszczyk
The problem of interaction between a floating ice cover and an engineering structure is considered, in which the ice–structure contact forces are caused by an increase in ice temperature due to solar radiation in situations, when the lateral thermal expansion of ice is constrained. The focus is on the determination of the maximum thermally-induced horizontal force exerted on a structure wall, assuming
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Fluid forces acting on three and four long side-by-side flexible cylinders undergoing flow-induced vibration(FIV) Mar. Struct. (IF 2.708) Pub Date : 2020-11-06 Wanhai Xu; Shuhai Zhang; Yexuan Ma; Bin Liu
Multiple side-by-side cylinders are widely employed in many engineering applications. Consequently, flow-induced vibrations (FIV), which have a significant influence on structural reliability, have drawn considerable concern from many investigators. Due to the complicated wake interactions behind the cylinders, the hydrodynamic characteristics of multiple side-by-side cylinders subject to FIV are obviously
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Optimization of mooring systems in the context of an integrated design methodology Mar. Struct. (IF 2.708) Pub Date : 2020-11-01 Bruno da Fonseca Monteiro; Juliana Souza Baioco; Carl Horst Albrecht; Beatriz Souza Leite Pires de Lima; Breno Pinheiro Jacob
This work describes an enhanced mooring optimization procedure, oriented towards recent floating production systems (FPS) for oil & gas exploitation in ultra-deep-water scenarios, which may present a large number of risers in an asymmetric layout. Acknowledging that the risers are the key component of an FPS, the optimization procedure is associated to an integrated mooring-riser design methodology;
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Centrifuge modelling of pipe-soil interaction in clay with crust layer Mar. Struct. (IF 2.708) Pub Date : 2020-11-01 Zhechen Hou; Fauzan Sahdi; Christophe Gaudin; Mark Randolph
Seabed in regions, such as the Gulf of Guinea and North West Shelf of Australia, may exhibit a crust layer where the undrained shear strength can be an order of magnitude higher than that of the immediately underlying sediment. This can complicate design of steel catenary risers, where fatigue depends on the cyclic vertical stiffness of the pipe-soil interaction. Potential punch-through of the riser
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Strain-based fatigue reliability assessment of welded joints in ship structures Mar. Struct. (IF 2.708) Pub Date : 2020-11-01 Y. Dong; Y. Garbatov; C. Guedes Soares
A strain-based fatigue reliability assessment of welded ship structural joints is presented. To obtain a complete description of the fatigue stress acting on a butt-welded joint in a ship, a probabilistic distribution for the low cycle fatigue stress range is developed considering the uncertainty in the static and dynamic stresses. A model considering the effect of a secondary notch embedded into the
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Mean and unsteady loading on square prisms with rounded edges: Hard marine growth, incidence, and Reynolds number effects Mar. Struct. (IF 2.708) Pub Date : 2020-10-30 Nils Paul van Hinsberg
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A detailed finite element investigation of the effects of local lateral high-velocity impacts on the ultimate strength of unstiffened steel plates subjected to uniaxial in-plane compression Mar. Struct. (IF 2.708) Pub Date : 2020-10-21 Hamid Moaieri; Mohammad Reza Khedmati
In this paper, the ultimate strength of unstiffened steel plates under uniaxial in-plane compression is numerically studied considering the local lateral impact of a rigid-body impactor. The plates are made of mild steel, where its behaviour is modelled by using the Johnson-Cook material model. The material parameters of the Johnson-Cook material model calibrated by the authors were employed for predicting
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Time-domain structural analysis during block turnover and lifting using 2D flexible multibody dynamics Mar. Struct. (IF 2.708) Pub Date : 2020-10-28 Seung-Ho Ham; Myung-Il Roh
Ship construction involves the assembly of several blocks on a dock. When a block is lifted using a crane, it undergoes deformation. Until now, structural analysis has been applied in a few cases to evaluate the stress on such blocks. Therefore, this study proposes an evaluation method for time-domain stress using 2D flexible multibody dynamics. We adopt the discrete Euler-Lagrange equation to achieve
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The influence of fluid structure interaction modelling on the dynamic response of ships subject to collision and grounding Mar. Struct. (IF 2.708) Pub Date : 2020-10-21 Sang Jin Kim; Mihkel Kõrgersaar; Nima Ahmadi; Ghalib Taimuri; Pentti Kujala; Spyros Hirdaris
Analysis of the dynamic response of ships in accident scenarios requires a realistic idealisation of environmental and operational conditions by multi-physics models. This paper presents a procedure that simulates the influence of strongly coupled FSI effects on the dynamic response of ships involved in typical collision and grounding events. Our method couples an explicit 6-DoF structural dynamic
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Fatigue predictions for flexible marine propellers using FSI analysis considering Euler force in the rotating frame Mar. Struct. (IF 2.708) Pub Date : 2020-10-20 Beom-Jin Joe; Yo-Seb Choi; Won-Seok Jang; Suk-Yoon Hong; Jee-Hun Song; Hyun-Wung Kwon
Analysis of flexible marine propellers in terms of their structural response and stress is the key to accurate fatigue prediction. At present, finite element method (FEM) analyses of flexible propellers have been performed as a part of the fluid–structure interaction (FSI) analysis using a numerical method for the flexible structures, which is identical to that used for their rigid counterparts. In
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Time-domain coupled dynamic simulation for SFT-mooring-train interaction in waves and earthquakes Mar. Struct. (IF 2.708) Pub Date : 2020-10-21 Chungkuk Jin; Farid P. Bakti; MooHyun Kim
In this study, Submerged Floating Tunnel (SFT)-mooring-train coupled dynamics is solved in the time domain to investigate their dynamic and hydro-elastic interactions under wave and earthquake excitations. The SFT is modeled by the rod-FE (finite element) theory, and it is connected to mooring lines through dummy-connection-mass and linear and rotational springs. A 3D rigid-multi-body dynamic model
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Crack growth direction effects on corrosion-fatigue behaviour of offshore wind turbine steel weldments Mar. Struct. (IF 2.708) Pub Date : 2020-10-24 Anais Jacob; Ali Mehmanparast
In this study corrosion-fatigue tests have been conducted on fracture mechanics specimens extracted from an S355 G10+M structural steel welded plate. The tests have been performed on compact tension specimens with the crack tip located in the heat affected zone. The corrosion-fatigue test results from this study have been compared with the data available on the base metal as well as air tests on the
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Glacial ice impacts: Part II: Damage assessment and ice-structure interactions in accidental limit states (ALS) Mar. Struct. (IF 2.708) Pub Date : 2020-10-28 Zhaolong Yu; Wenjun Lu; Marnix van den Berg; Jørgen Amdahl; Sveinung Løset
Floating glacial ice features of various sizes pose a substantial threat to the structural integrity of offshore structures in ice-prone regions. Relatively small ice feathers, e.g., bergy bits and growlers, are a major concern because they are more difficult to detect by marine radars and perform concurrent ice management operations, especially in extreme sea states. This two-part companion paper
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Fatigue analysis of water intake risers: Hydrodynamic damping effect and a hybrid frequency-time domain method Mar. Struct. (IF 2.708) Pub Date : 2020-10-28 Zhenguo Gao; Mike Efthymiou; Liang Cheng; Tongming Zhou; Matthieu Minguez; Wenhua Zhao
The fatigue performance is key to the design of water intake risers (WIRs), which is a novel concept used to convey cooling water for liquefaction of natural gas at sea. To estimate the fatigue life, it is crucial to accurately predict the response amplitude of the WIRs, which is dominated by hydrodynamic damping. In operational conditions, the motion amplitudes of WIRs are usually smaller than their
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