bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Simulation of Marine and Coastal Zone Multidimensional System Sustainable Development
Authors: Deng Yue , Li Yaning , Li Jiarui , Sun Yanli , Cao Yingzhi , Zhao Jingli 
Published: September 2023

Abstract
The long-term strategy of Blue Economy aims to release the potential of marine resources through the sustainable development of the production system of marine products and renewable marine resources. As one of the most dynamic areas for the development of blue economy, the coastal zone is also a zone with strong interaction between land and sea. It is a complex nonlinear system with the most intensive space development and utilization, the most prominent pressure on resources and environment, and the most concentrated contradictions. This study uses the system dynamics method to establish the marine model and the coastal model, calculates and analyzes the sustainable development of the ocean and coastal zone system through the coupling of the land and the ocean model, focuses on the development of marine renewable energy, aquaculture, fisheries, marine pollution, marine engineering and other industries, as well as the development and utilization of marine resources, and studies the interaction between various factors. Better promote the development of marine blue economy through system coupling and coordinated development.
Fatigue Strength of 3” Subsea Pressure Containing Bolts in Air and Seawater Environment
Authors: Horn Agnes Marie , Fjeldstad Arne , Wernø Tore Geir , Muff Anthony D. 
Published: September 2023

Abstract
Three inch bolts have been fatigue tested to quantify the fatigue strength in air environment and seawater with cathodic protection. The motivation behind the laboratory test project was to justify the use of cathodic protection against corrosion for bolts used in subsea systems. In fatigue design standards such as DNV-RP-C203, the use of cathodic protection is not recommended for bolts because high strength steel is prone to hydrogen embrittlement when subjected to high loads. However, based on published fatigue test data of bolts the last 2–3 years the revised DNV-RP-C203 that is currently undergoing industry hearing has proposed the following update: “The recommended practice is valid for bolts in air environment for grades up to 10.9, ASTM A490 or equivalent. In seawater with cathodic protection the recommended practice is valid for grades up to 8.8 or equivalent.
Present industry subsea practice is to use preloaded bolts exposed to cathodic protection. The objective of this paper it to assess the fatigue strength of bolts with cut threads in seawater with cathodic protection. It will further be considered whether standard design principles can be assumed, more specifically if the difference in fatigue life between air and seawater environment can be assumed equal to a factor of 2.5. The long-term aim is to gather sufficient relevant laboratory test data such that a revision of the design recommendations for bolt operating in marine environment can be justified. This is considered important as the industry seem to prefer cathodic protection as primary means of protecting bolts against corrosion.
Experimental and Numerical Analysis on the Hydrodynamic Force of an Ice Piece in Synthetic Brash Ices With Defined Distance
Authors: Hayashi Ryota , Konno Akihisa , Zhou Jinxin , Li Qiao , Dong Shuchuang , Kitazawa Daisuke 
Published: September 2023

Abstract
The necessity of the Arctic route has promoted the development of polar ships, whose power requirements must be evaluated due to brash ices covering that region. The ice resistance is required in one approach of ship power estimations. However, the hydrodynamic force calculation in brash ices has not been fully generalized. In this study, the horizontal hydrodynamic force of an ice piece in synthetic brash ices was examined experimentally and numerically. The towing experiment was conducted at the water tank of the Marine Ecosystem Engineering Laboratory, Institute of Industrial Science, the University of Tokyo. Using identical specifications to the experiments, numerical calculations were conducted using the volume of fluid method, which is embedded in the Simcenter STAR-CCM+ platform. The force of one ice piece moving downstream of another increased linearly, while only the trend had been numerically reproduced. The present brash ices were arranged in a staggered manner, and the relationship between the force of the measured ice and the rows of ice pieces in its front was examined. In the experiments but not in the calculations, the force on the measured ice increased almost linearly. Further investigation is necessary to improve the numerical simulation and estimate the power of polar ships.
Nonlinear and Extreme Wave Group Interactions With a Circular Cylinder
Authors: He Yuchen , Kanehira Taiga , Mori Nobuhito , Gamaleldin Muhannad , Babanin Alexander , Chauhan Kapil , Chabchoub Amin 
Published: September 2023

Abstract
The evaluation of extreme wave kinematics is decisive to determine design standards for marine structures. Offshore rogue waves in high wind areas can emerge as a consequence of unstable wave group focusing. Large-amplitude waves in such wave groups have different kinematic properties compared to those resulting from the superposition principle. This experimental study has been carried out to evaluate the wave load forces of highest amplitudes within unstable wave groups acting on a submerged, vertical, and circular cylinder. Different wave steepness parameters have been systematically adopted. It is shown that for moderate steepness values the wave loads show the presence of three harmonic components. Higher wave steepness parameters are responsible for the change of the cylinder’s response in the form of a transient ringing. In fact, even though higher harmonics of the underlying regular wave trains do not resonate with the lowest resonant frequency of the cylinder, the severe broadening of the wave spectra in all bound wave components, resulting from the wave focusing within the unstable wave packet, triggers a ringing frequency excitation.
Numerical Study of Underwater Implosion of Spherical Pressure Hull on Deep-Sea Submersibles
Authors: Zheng Jiancai , He Yupei , Zhao Min 
Published: September 2023

Abstract
The failure of the pressure hull is the key subsystem of underwater vehicles, and seriously threatens the vitality of the whole underwater vehicle. Moreover, the shock waves from underwater implosions of failure pressure hull will cause deformation and even collapse to the adjacent structures, which is detrimental to the vehicles such as underwater robots and manned deep submersible vehicles working in the deep sea environment. In this work, the open-source solver OpenRadioss is adopted to conduct the numerical analysis of the spherical pressure hull within the shock waves of the underwater implosion and structure deformation and failure. The compressible multiphase flow is simulated by the arbitrary Lagrange-Euler method with multi-physical materials and the structures are described by constitutive models of brittleness and metal ductility, respectively. Firstly, the underwater implosion of a thin-glass sphere is simulated. The pressure of shock waves is compared with the experiment to verify the accuracy of the numerical method. Secondly, the dynamic response of the spherical hollow ceramic pressure hulls with internal perfect gas is investigated accordingly to reveal the fluid-structure coupling effects of underwater implosion induced by the failure of brittle materials, where the structure no longer bears any pressure after failure. Finally, the underwater implosion under the same environment pressure is simulated based on the Johnson-Cook plasticity and failure model. The implosion characteristics in the failure process of metal pressure hulls are summarized by analyzing the coupling pressure, structural deformation and damage, and energy evolution, respectively. Moreover, the differences between the hollow brittle ceramic sphere and ductile titanium alloy sphere in the process of underwater implosion are discussed. The influence of fluid-structure interaction and the mechanism without different materials are analyzed for the spherical pressure hull, which provides a basis for the design and material selection of the pressure support structure of the underwater vehicle.
A Model for Friction Stresses in Cable Core
Authors: Skeie Geir , Sødahl Nils , Pettersen Sune , Verde Lars Helge 
Published: September 2023

Abstract
Accurate evaluation of friction stress is important for reliable fatigue life calculations of High Voltage Alternating Current cables used in off-shore wind installation. The cable cross section lay-up place the power-phase in the center of the cross section resulting in circumferential contact between the components. The stick-slip evolution for components in circumferential contact is different than for components in radial layer contact. A model for both onset and progression of slip for a three-core power phase design is explored. The slip progression involves equilibrium considerations of all three components. The slip zones of the individual components evolve in the longitudinal direction until they coalesce. The knowledge of global behaviour of slip onset and progression allows evaluation of bending and friction stresses on one individual component. This is similar to the bending and slip of a helix component resting on a cylinder layer. The assumptions used to verify the stick-slip progression are verified by numerical simulations.
The Effect of Steady Currents in Weather Downtime Assessment
Authors: Schira Bepo , Shoukat Gohar , Thusyanthan Indrasenan 
Published: September 2023

Abstract
Weather downtime is a major factor in any offshore operation as it affects both the project program and budget. Therefore, knowledge of potential weather downtime for a given site is valuable to de-risk the project by improved planning and estimates of the financial performance.
Severe sea states limit the allowable operational time offshore, thus extending the time required to complete the project. The metocean parameters used to estimate the weather impact on offshore operations are usually wind speed, significant wave height and wave period. However, steady currents may significantly impact the project, even during workable sea state conditions. This can especially be the case in offshore windfarms construction as they are often located in shallow water areas with high currents making it crucial to understand their effects on the weather downtime.
In this paper we discuss how the effect of the currents may be more realistically accounted for in weather downtime estimations by considering the “waiting on current periods”, or the time the construction vessel will have to cease the operations due to periods of peak currents within an otherwise workable weather window. To understand this effect, we have developed a tool known as “GDG-WDAT” which is capable of interacting with the ERA5 database, enabling effective operational planning and cost savings in offshore operations.
On the Development of Aft Body Hull Form for Ship-Type Offshore Structures
Authors: Kim Joo-Sung , Song Gi Su , Son Hye-Jong , Kim Bo Hee , Park Jung Ki , Kim Hyun Joe 
Published: September 2023

Abstract
This paper describes in detail the hydrodynamic issues examined in the development of aft body hull form equipped with three azimuth thrusters. Hydrodynamic performance considered include roll damping, transit performance, thruster interference with hull and with other thrusters, and stern slamming. Constructability issues which may be encountered during a fabrication stage are discussed. Two issues are examined; bilge keel and headbox.
The transit performance is assessed using model testing and CFD simulation. The conventional barge-type hull without headbox leads to much lower resistance. However, when large headboxes are added, the transit performance for the two hulls is almost similar to each other. The thruster-hull and thruster-thruster interactions are examined using CFD simulation. The results clearly show that the flat bottom hull leads to lower thruster-hull interaction and provides greater flexibility of thruster arrangement.
Squeeze Cementing, a Mathematical Model and Parametric Investigation
Authors: Izadi Mahdi , Frigaard Ian A. , Taghavi Seyed Mohammad 
Published: September 2023

Abstract
This paper discusses the capabilities of a developed numerical framework for modeling squeeze cementing, in terms of a constant pressure displacement of a Newtonian preflush by a viscoplastic suspension, representing cement slurry. The approach is a continuum model, based on the Suspension Balance Model, which takes particle migration into account and considers the effects of particles on the jamming and the shear-dependent rheology of the suspending fluid, which allows exploration of different stoppage mechanisms. The model considers the transition from suspension flow into a packed bed formation and the possibility of interstitial flow, leading to interesting dispersion effects. This paper investigates slurry penetration in a long conduit with different conditions, quantifies the solid concentration, the penetration length and time, and the stoppage mechanisms in various scenarios over relevant parameter ranges. We show that the transversal distribution of particles in yield stress fluids can be non-monotone adjacent to unyielded regions and predict depleted layers close to the wall.
Cognitive Models for Human Reliability Analysis Applications to the Oil & Gas Industry
Authors: Alvarenga Marco Antonio Bayout , Frutuoso e Melo Paulo Fernando , Maturana Marcos C. , Martins Marcelo Ramos 
Published: September 2023

Abstract
In the quantitative risk analysis (QRA) of O & G equipment, it is necessary to consider the application of cognitive models (in use in the nuclear industry), which can very effectively predict human performance. First generation Human Reliability Analysis (HRA) methods are used in O&G primarily in an emergency scenario QRA and second-generation methods for design and normal operation. These methods can be inefficient. First generation HRA models do not have a cognitive architecture capable of processing human information. Second-generation models consider mechanisms of cognitive errors. Most of third generation HRA models are dynamic simulations of cognitive tasks, coupled with an event/accident simulation code, often designed more for human-machine interface assessment than for human error analysis. There are also cognitive psychology models designed to assess human performance without the intention of serving as HRA tools. These models have a detailed understanding of the cognitive mechanisms of human error, which is the key to a complete HRA model. One of these models, ACT-R, contains adequate quantification to serve as an HRA model. This article discusses cognitive psychology models and their internal structures in human information processing to provide human error probabilities that arise from the architecture itself and are not dependent on Performance Shaping Factors (PSFs), which are quantified by HRA current methodologies.
Wave Attenuation by Submerged Oscillating Plates
Authors: Chen Yongbo , Hayatdavoodi Masoud , Zhao Binbin , Ertekin R. Cengiz 
Published: September 2023

Abstract
Submerged oscillating plates are used as heaving plates to reduce the motion of floating objects, in wave energy devices to extract the wave energy, and as breakwaters to attenuate the wave field in shallow water. In this study, we consider a horizontal, submerged plate in shallow water that is allowed to oscillate in the vertical direction due to the wave loads. The plate is attached to a linear spring and damper to control the oscillations. The focus of this study is on the transformation of the wave field by the submerged oscillating plate. To estimate the energy attenuation, wave reflection and transmission coefficients are determined from four wave gauges; two placed upwave and two placed downwave of the oscillating plate. The fluid is governed by the nonlinear Level I Green-Naghdi (GN) equations, coupled with the equations of vertical motion of the plate to determine its oscillations. Time series of water surface elevation recorded at gauges upwave and downwave of the plate, and the wave-induced plate oscillations, obtained by the GN model are compared with available laboratory experiments and other data, and very good agreement is observed. Wave reflection and transmission coefficients are then determined for a range of involved parameters, including wave condition (wave height and wave period), initial submergence depth of the plate, plate length, and the spring-damper system. It is found that a single submerged oscillating plate can have remarkable effect on the wave field, and that nonlinearity plays an important role in this wave-structure interaction problem. Discussion is provided on how the wave reflection and transmission vary with the wave condition, plate characteristic, initial submergence depth and spring-damper system.
DEA Model Applied to Risk Based Inspection for Offshore Flexible Pipelines With Virtual Relative Risk Frontier From Event Trees
Authors: Jaques Honorato Henrique , Antoun Netto Theodoro , Lourenço De Souza Marcelo Igor , Ferraz Netto Carolina 
Published: September 2023

Abstract
The identification of the main nonconformities (NCIs) that occur in offshore flexible pipelines, as well as the recognition of failure mechanisms through event trees, are fundamental points for the generation of the risk-based inspection methodology (RBI-Flex) of these Structures. To ensure the operational safety of subsea flexible pipelines, it is essential to identify the main failure modes that can lead to the total loss of structural integrity due to leakage. In the methodology proposed here, the Submarine Risers System will be subdivided into inspection regions, to better calculate the relative risk of failure to the DEA (Data Envelopment Analysis). The organization of failure mechanisms through event trees allows the visualization of the chronological occurrence of nonconformities in the stages until the final failure mode is reached, which will be the top event. This article aims to propose a two-dimensional and multidimensional DEA model for assessing the relative risk of loss of structural integrity in a scenario whose risk boundary is calibrated by virtual pipelines. In this sense, it is possible to model the temporal evolution of nonconformities at each inspection instant. The DEA RBI Flex model generates a decision-making tool for inspection teams through risk rankings.
A Preliminary Study of Learning a Wave Energy Converter System Using Physics-Informed Neural Network Method
Authors: Chen Bo-Chen , Yu Yi-Hsiang 
Published: September 2023

Abstract
Physics-informed neural network (PINN) is a new type of neural network method that can be used to solve the physical problem by providing a given data set in the machine learning process with embedded physics information directly described by differential equations. A PINN model was applied in this study to solve the governing equation of motion for the analysis of a floating sphere wave energy converter (WEC), and a time-series segmentation approach was implemented to effectively handle the time-dependent problem. A series of PINN simulations are presented in this paper, including a decay test and a set of wave conditions, where the PINN solutions are verified against those obtained from other time-domain numerical models. This work aims to investigate the feasibility of using PINN for WEC applications with a focus on numerical benchmarking, and the studies of collection point resolution, the overall model accuracy, and the corresponding computational efficiency are also investigated.
Flow-Induced Vibration Analysis Using a Low-Cost Inertial Measurement Unit
Authors: Peres Leal Aline , Luís Condino Fujarra André , Matos Carnier Rodrigo , Trentin Gonçalves Rodolfo , Suzuki Hideyuki 
Published: September 2023

Abstract
Flow-induced movements have been investigated for more than 20 years, especially in offshore platforms, where Vortex-Induced Movements (VIM) impact platform productivity, mooring lines, and risers fatigue life. However, monitoring these systems with standard methods (i.e. robots) is very expensive. In this work, a low-cost alternative is developed: we carried out experiments in the towing tank at The University of Tokyo (UTokyo), measuring the movements of a spar-type platform model with a low-cost Inertial Measurement Unit (IMU). The IMU application is beyond the computation of orientation: by measuring movements, displacement amplitudes and frequencies, we analyzed Flow-Induced Vibrations (FIV) in the spar model. The model was free to move in six degrees of freedom (6DOF), while its acceleration, rotation rate and magnetic field were recorded using the commercial IMU GY-87. A robust signal treatment methodology is developed based on the Kalman filter, Fast Fourier Transform (FFT) filter, Intrinsic Mode Function (IMF) decomposition, and coordinate manipulation using quaternion rotations, to remove drift and noise problems, and extract the model displacement in the three axes. The IMU application is evaluated by comparing its results with a high-accuracy optical tracking system, showing the potential of low-cost sensors for FIV analysis. Maximum amplitudes were found for cross-flow displacement at the reduced velocity VR = 10.13, with a significant amplitude of 0.7D for the IMU and 1D for the optical system.
Study of Crack Initiation and Fracture in OC4 Jacket Structure Under Cyclic Loading by Peridynamic Approach
Authors: Bachimanchi Pranitha , Saha Nilanjan 
Published: September 2023

Abstract
The offshore structures are frequently subjected to the cyclic loads generated by environmental conditions leading to structural damage. The analysis of such damage that manifest as cracks become non-trivial due to mathematical abstraction of their classical governing equations in the presence of structural discontinuities. In this study, we employ peridynamic theory [1] that modifies the classical mathematical model by replacing spatial derivatives with integrals through non-local bond interactions between material points. This approach helps us model the breakage of bonds pertaining to structural cracks. In the peridynamic fatigue model [2], the breakage of bonds is evaluated through the remaining life parameter that accounts for the cumulative damage at every load cycle caused by in-plane cyclic deformation in a 2D plate. In this work, we model OC4 jackets with peridynamic beam formulation [3], where the fatigue model considers the bond’s cyclic in-plane, shear, bending, and torsional deformation. We successfully identify the critical locations for crack initiation in the jacket under constant amplitude cyclic point loading. We further evaluate the number of load cycles required for crack initiation and fracture under different maximum load magnitudes of cyclic loading.
Seakeeping Behavior of a Helicopter Landing in Waves
Authors: Tadashi Katsuno Eduardo , Peters Andreas , El Moctar Ould 
Published: September 2023

Abstract
This work analyzed the behavior of a helicopter that needed to land in water and compared the results from two methods, Boundary Element Method (BEM) and Computational Fluid Dynamics (CFD), in terms of their predictions of the helicopter’s response to waves. The study concluded that while BEM can provide quick results for estimating loads on the floaters in not-so-rough wave conditions, it cannot predict capsizing and should be used with caution. On the other hand, CFD can provide accurate results, but it has a higher computational cost. The results of the study showed that BEM and CFD produce similar results in terms of the natural period of roll and pitch, and that the time-domain simulation of 600 seconds using BEM can be used to estimate cabin acceleration. However, CFD simulations are necessary to check for capsize or water inside the cabin in future works.