bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Fast Algorithm for the Prediction of Distance at Closest Point of Approach in the Maneuvering of Two Ships
Authors: Xu Chen , Jiang Fan , Xu Chaozuo , Zhou Xueqian , Ren Huilong 
Published: September 2023

Abstract
The situation of two ships maneuvering in the vicinity is not so rare, and the significant hydrodynamic interaction effect always poses a threat to navigation safety in these conditions. The assessment of distance at closest point of approach (DCPA) is necessary for ship collision avoidance decision-making. In this study, an efficient ship maneuvering model for close-distance maneuvering is developed to predict DCPA rapidly, where the hydrodynamic interaction between ships is accounted for. The MMG model is used to predict ship motion, and the hydrodynamic interaction effect is estimated in real-time by a code based on the potential flow theory where the variation of free surface is neglected. The ship maneuvering model is validated by the comparison between simulation and experiment in turning and zig-zag maneuvering, furthermore, the validated maneuvering model is used to predict the trajectory under the ship hydrodynamic effect. The characteristic of ship maneuvering under the ship hydrodynamic interaction between two ships is described and illustrated, and the influence of the velocity and lateral distance on the ship trajectory is revealed. A sensitivity analysis of the maneuvering model is performed to determine whether the hydrodynamic interaction effect is necessary to be evaluated exactly for an accurate predicted trajectory and DCPA. The DCPA in different situations are calculated which represents the ship collision risk.
Some Background for the 2023 Revision of the Recommended Practice DNV-RP-C203 Fatigue Design of Offshore Steel Structures
Authors: Lotsberg Inge , Fjeldstad Arne 
Published: September 2023

Abstract
The recommended practice DNV-RP-C203 Fatigue Design of Offshore Steel Structures has been regularly revised since it was first published in 1998. The reasons for these revisions are new data and new learnings from design and in-service experience from installed structures. The standard is also being used for new types of details and structures, and this requires new information to the users of the document. New literature is being published and other standards related to fatigue design is being revised; therefore, a regular revision of this document is needed.
The standard is being used for fatigue design of different structures such as jackets, risers, pipelines, semisubmersibles, spars, floating production vessels, fixed and floating structures for support of wind turbine structures, different types of connectors, etc. This implies that the content needs to be applicable for many different details where the efficiency and reliability of the methods used are being challenged by the industry. During the last year the recommended practice has been through a critical review where the content has been updated where new information has become available.
Trustworthiness Evaluation Framework for Digital Ship Navigators in Bridge Simulator Environments
Authors: Namazi Hosna , Perera Lokukaluge Prasad 
Published: September 2023

Abstract
The maritime industry is going towards implementing digital navigators, i.e., AI created by machine learning algorithms, on autonomous vessels in the future. Digital navigators can be developed by utilizing machine learning algorithms, e.g., deep learning type neural networks trained by data sets from human navigators. Even though there is significant importance in studying the trustworthiness of these digital navigators, a proper framework to evaluate it has not yet been developed. This study identifies the appropriate key performance indicators (KPIs) in the trustworthiness of digital navigators in autonomous vessels.
The trustworthiness of AI-based applications, including digital navigators, can be studied from two primary levels: Software and hardware levels. Each of these levels must have certain characteristics to be called trustworthy. In other words, software codes and algorithms should be Transparent, i.e., Explainable, Fair, and Accountable/Responsible. Moreover, the trustworthiness at the hardware level can be elaborated under two concepts of Resilience and Availability of the relevant systems and technologies. In addition, some concepts, such as Reliability, Privacy, Security, and Safety, should be studied for both levels since those concepts can overlap in both software and hardware levels.
In this paper, the main focus is on investigating the software level’s trustworthiness. After an introduction on the importance of the topic and digital navigator’s development steps, the existing literature on trustworthy AI is reviewed, and the proper approaches for evaluating trustworthiness in AI-based digital navigators are identified and proposed.
RANS Simulations of Propeller-Hull Interaction in Model Scale With the Best-Practice Settings
Authors: Jin Shanqin , Peng Heather , Qiu Wei 
Published: September 2023

Abstract
Extensive convergence studies for the KCS hull model had been carried out, and the best-practice settings were summarized in our previous work [1]. Compared with the experimental results, the best-practice settings were verified in this work by applying them to simulations of the Japan Bulk Carrier (JBC) and KRISO Very Large Crude Carrier V.2 (KVLCC2) models. Bare-hull resistance and propeller open-water performance were first examined. For propeller-hull interaction, both the body-force method and the detailed propeller modelling method were applied to predict the wake fraction and propeller performance behind the hull. Furthermore, the pseudo effective wake fraction determined from CFD simulations was introduced and compared with experimental data.
Localization and Mapping for Deep-Sea Mining Vehicles With Forward-Looking Sonar
Authors: Xu Wenhao , Yang Jianmin , Wei Handi , Lu Haining , Tian Xinliang , Liu Lei 
Published: September 2023

Abstract
The deep-sea mining vehicle is one of the critical equipment of the deep-sea mining system, which is used to collect manganese nodules or other minerals on the seafloor. When the deep-sea mining vehicles works, a reliable localization system is essential. In addition, the ability to sense and model the surrounding environment in real time is also necessary for the safe and efficient operation for deep-sea mining vehicles. This study developed and validated a localization and mapping algorithm. The localization algorithm uses extended Kalman filtering fusing inertial measurement unit, ultrashort baseline, a compass, track encoders and forward-looking image sonar. The mapping algorithm relies on forward-looking image sonar and the position output by the localization algorithm. The environment map is a grid map to meet the requirements of obstacle avoidance and path planning for deep-sea mining vehicles. A deep-sea mining vehicle named ‘“Pioneer I” which was designed and developed by Shanghai Jiao Tong University has been tested in the South China Sea. All the data of sensors in the sea trials were recorded with time synchronization based on the software framework. Therefore, the sensor data from the sea trials can be used as input for validation of the proposed localization and mapping algorithm.
A Simplified Model of the Carcass Axial Capacity for Unbonded Flexible Pipes Under Differential Pressure Loading
Authors: Zhu Linfa , Liu Jian , Tan Zhimin , Roberts Andrew 
Published: September 2023

Abstract
The formation of hydrate plugs can lead to a significant operational risk to a flexible pipe when uncontrolled differential pressure builds up across a blockage. After a hydrate plug is completely formed, it can fill all the voids within the carcass profile and the gap between the carcass and pressure sheath layers. This bonding mechanism constrains the relative movement of the carcass and pressure sheath layers at the hydrate plug section. The axial end cap force from the differential pressure acts on the formed hydrate plug and the load is directly transferred to the carcass and pressure sheath layers. If large enough, this load could tear the carcass layer apart, and damage the pressure sheath layer which leads to catastrophic failure of the pipe structure. It is important to assess the limiting capacity of such failure mode to assure safe operation.
In this paper, a carcass axial capacity prediction model is presented for flexible pipes under differential pressure loading based on the characteristics of the deformations of the carcass and pressure sheath layers near the hydrate plug. The total axial capacity is predicted by the combination of a 2D finite element model for the carcass layer and a simplified analytical model for the pressure sheath layer. Detailed quantitative analysis results of a given flexible pipe are presented and compared with the test results. The design parameters impacting the model prediction are explored.
Numerical Simulation of the Deflection of Jellyfish due to Air Bubble Curtains
Authors: Liu Lei , Talimi Vandad , Thodi Premkumar , Gauthier David , Paris Mario 
Published: September 2023

Abstract
Increased jellyfish blooms have gained more attention recently due to their tendency to clog seawater intake systems of nuclear power plant cooling stations and threaten marine fish farms. The Bubble Tubing for Jellyfish Deflection Project (BTJD) was conducted by C-CORE to investigate the efficiency of Canadian Pond.ca’s Bubble Tubing® for jellyfish deflection. A three-dimensional Computational Fluid Dynamics (CFD) model was developed to quantify air bubble curtain performance for jellyfish deflection. The commercial CFD package STAR-CCM+ was used for this purpose. The multi-phase (water and air) fluid flow dynamics were simulated by solving Reynolds Averaged Navier Stokes (RANS) equation. The Discrete Element Modeling (DEM) approach was utilized to model the individual jellyfish behavior. The CFD model was initially used to optimize the flume tank test design, and then the model was validated using the test results from the flume tank. CFD simulations covered a range of test parameters such as current speed, number of curtains, curtain spacing, bubbler angles and air flow rates. Good agreement was observed between the CFD simulations and flume tank test results. The developed CFD model can be utilized for similar applications at field scales.
Buckling and Post-Buckling Behaviour of Extruded Aluminium Panels Subject to the Combined Effects of Welding and Pitting Corrosion
Authors: Mokhtari Mojtaba , Wang Xintong , Amdahl Jørgen 
Published: September 2023

Abstract
The present study investigates the effects of pitting corrosion and welding, both independently and combined, on the buckling and post-buckling behaviour of extruded aluminium panels. For this purpose, a finite element model of an aluminium panel made of AA6082-T6 extruded profiles is first developed without having the pitting corrosion and welding effects considered. Then, this finite element model is upgraded to account for the welding effects. This is followed by the validation of the upgraded model against the experimental data obtained from the literature. After the model validation, a hierarchical stochastic algorithm is utilised to simulate the pitting corrosion attack as geometrical defects distributed on the surface of both finite element models, with and without the welding-induced imperfections. Two different corrosion scenarios are considered. In the first scenario, the plating is corroded while the stiffeners remain intact. In the second scenario, the plating is intact, and the stiffeners contain pitting corrosion defects. The corroded parts are modelled with solid, hexahedral elements while shell elements are employed elsewhere. The effect of element type on the numerical results is discussed. Ultimately, the results obtained from the finite element models with and without corrosion and welding effects are compared in terms of ultimate strength, post-buckling response and stress/strain distribution.
RANS Simulations of Self-Propulsion Model Tests for a Fishing Vessel
Authors: Cilkaya Emre , Peng Heather , Qiu Wei 
Published: September 2023

Abstract
This paper presents the self-propulsion simulations for a fishing vessel with an optimized bulbous bow and a four-bladed fixed-pitch propeller using the RANS solver in the open-source Computational Fluid Dynamics (CFD) package OpenFOAM. Steady simulations were carried out at the design speed without a propeller to validate the bare-hull resistance results against the experimental data. The open-water hydrodynamic characteristics of the propeller were then simulated with the Moving Reference Frame (MRF). Finally, the self-propulsion simulations were performed by changing the propeller rotational speed with the same forward speed. The propeller thrust and torque coefficients were compared with the experimental data. Discrepancies between the experimental measurements and the numerical results on the towing forces were observed.
Developments of the Glen Lyon FPSO Digital Twin: Vessel Response and Structural Monitoring
Authors: Bailey Jonathan , Bamford Richard J. , Das Suvabrata , Maroju Soma S. , Barker Robert J. 
Published: September 2023

Abstract
This paper presents the continuing developments of the Glen Lyon FPSO Digital Twin. The objective of the Glen Lyon Digital Twin has always been to monitor and inform structural barrier health and verify operation within the allowable design limits. A detailed vessel motion response and loads monitoring is being undertaken to keep track of the fatigue life consumption of the hull structure, and to take mitigating actions as needed to maintain integrity. The structural response monitoring system onboard is contained within the vessel’s Integrated Marine Monitoring System (IMMS), which consists of various sensors, including accelerometers and strain gauges. The measurements from these are accessed and post-processed through BMT DEEP, harnessing the benefits of Digital Twin Technology, by bringing in data from all sources and enabling to synthesize and monitor the FPSO response in near real-time from any remote location.
The structural dashboard monitors the vessel dynamic stability, relative environment headings, and vessel offsets, through several statistical distribution charts. The hull girder bending moments are continuously monitored through deflections measured by the deck strain gauges. Also, the vessel fatigue damage is computed from the deck strain gauge measurements. Apart from these, the vessel motion responses like relative wave elevations and vertical accelerations at the turret center, are being utilized to help monitor vessel fatigue life consumption by comparison with established fatigue curves using these parameters. Comparisons are made with the predicted fatigue damage rates during the vessel design. Some key insights and findings from these comparisons are presented. The challenges faced in this process are highlighted, along with the steps taken to overcome those.
Performance Feasibility of a Multi-Source Offshore Renewable Energy Platform for Aquaculture
Authors: Roberts Sophie , Howe Damon , Nader Jean-Roch 
Published: September 2023

Abstract
The global aquaculture industry is facing new challenges as it strives to satisfy the continually growing demand for seafood products. The expanding industry brings with it challenges such as the diminishing availability of suitable coastal zones due to increased competition for marine-use areas, and a responsibility to limit negative impacts to the environment. As a potential solution to the negate environmental impact and continue industry expansion, operations are expected to transition further offshore. Moving aquaculture operations offshore presents several challenges, foremost of which is the provision of energy. This paper explores the feasibility of using a novel multi-source renewable energy platform to overcome the reliance on diesel in the offshore aquaculture industry. Through the development of a numerical model, this solution proposes a scalable renewable energy platform located off the coast of Tasmania utilising solar photovoltaic (PV), wind turbines and wave energy conversion. The feasibility is assessed through a numerical model based on factors such as resource availability, energy demand and conversion system efficiencies to determine how different design and resource variable influence the ability of the platform to meet the energy requirements.
Relating the Stiffness of Load-Transfer Functions for Monopile Foundations to Elastic Soil Modulus
Authors: Doherty James , Randolph Mark , Wan Xiao 
Published: September 2023

Abstract
Estimating the stiffness of large diameter monopiles used to support offshore wind turbines is an important step in the design process. This is generally done using load-transfer functions in the form of independent (Winkler) springs to represent the relationship between the net soil resistance at any depth adjacent to a pile (p) and the lateral deflection of the pile at the same depth (y). Recent studies for monopiles, which have low length to diameter ratios and high moment loading, have led to recommendations for additional moment-rotational, or m-θ, springs distributed along the shaft of the monopile, as well as base lateral and rotational springs. A significant challenge in applying these new recommendations is to relate the load-transfer functions to conventional soil properties. A simple ‘Step 0’ design approach has derived relationships between the initial stiffness values of the load-transfer functions and the elastic modulus of the soil at a given depth. In this paper, the accuracy of these relationships is examined for a more complex, layered soil profile that includes realistic but abrupt changes in soil modulus. It shown that once a soil modulus profile is established, a reasonably accurate estimate of the stiffness of a monopile can be obtained, sufficient for initial design calculations, without the need for more onerous 3D FEA.
Investigation of Theoretical Solutions to a Bottom-Raised Oscillating Surge Wave Energy Converter (OSWEC) Through Experimental and Parametric Studies
Authors: Nguyen Nhu , Davis Jacob , Thiagarajan Krish , Tom Nathan , Husain Salman 
Published: September 2023

Abstract
Experiments were conducted on a wave tank model of a bottom raised oscillating surge wave energy converter (OSWEC) model in regular waves. The OSWEC model shape was a thin rectangular flap, which was allowed to pitch in response to incident waves about a hinge located at the intersection of the flap and the top of the supporting foundation. Torsion springs were added to the hinge in order to position the pitch natural frequency at the center of the wave frequency range of the wave maker. The flap motion as well as the loads at the base of the foundation were measured. The OSWEC was modeled analytically using elliptic functions in order to obtain closed form expressions for added mass and radiation damping coefficients, along with the excitation force and torque. These formulations were derived and reported in a previous publication by the authors. While analytical predictions of the foundation loads agree very well with experiments, large discrepancies are seen in the pitch response close to resonance. These differences are analyzed by conducting a sensitivity study, in which system parameters, including damping and added mass values, are varied. The likely contributors to the differences between predictions and experiments are attributed to tank reflections, standing waves that can occur in long, narrow wave tanks, as well as the thin plate assumption employed in the analytical approach.
Stability of Concrete Mattresses
Authors: O’Brien Dermot , Draper Scott , An Hongwei 
Published: September 2023

Abstract
Concrete mattresses are widely used in the offshore industry for a variety of purposes, including to stabilise pipelines, flowlines and umbilicals, provide supports for span correction or crossings over other services and for scour mitigation.
Despite their widespread use, the stability of mattresses under hydrodynamic loading is not very well understood, an issue which is particularly apparent when the purpose of employing mattresses is to provide secondary stabilisation for a pipeline, flowline or umbilical against hydrodynamic loading. The complexity of the mattress shape does not easily lend itself to analytical solutions based on data presented in existing codes and papers, with the result that a conservative analysis of mattress stability is regularly adopted in project environments. Where the project requirement is for a small number of mattresses, this is not a significant issue, however where large numbers of mattresses are required, such conservative approaches can result in unnecessary project costs.
This paper presents the outcomes from two programs of physical model testing of mattresses specifically aimed at improving understanding of mattress stability under hydrodynamic loading, and the peak resistance that mattresses can provide to prevent flowline lateral movement when both the mattress and flowline are under hydrodynamic loading. While the physical model testing programs performed were tailored to specific project requirements, the testing results and means of application for those projects provide valuable insights to mattress stability under hydrodynamic loading, and a pathway to a less conservative approach to defining mattress requirements in such scenarios.
Challenges Associated With High Voltage Dynamic Inter Array Cables
Authors: Dobson Alan 
Published: September 2023

Abstract
Dynamic helical cables and umbilicals have been operating in a range of offshore environments for the past 35 years in support of Oil & Gas developments and from a range of hosts in a range of dynamic environments globally. With the advent of offshore wind power generation and more recently, the piloting of floating offshore wind power generation, the reliability of power cables is both a concern and a focus area for developers and operators as well as a research area for academia. Knowledge and lessons learnt from the Oil and Gas domain can be applied to the offshore floating wind domain but with some caveats. The paper will provide an insight into these lessons learnt and highlight critical risks with some potential mitigations.
There will be a focus upon system reliability with various modes of failure and the failure mechanisms discussed, such as material fatigue, creep, hydrolysis and corrosion, from a component perspective. Structural failure is also evaluated through a system perspective linking failure mechanism with global response of the riser cable and material degradation and ageing. In particular the coupled effects of mechanical, thermal and electromagnetic loading will be presented together with the design challenges they pose for installation, static and dynamic operation of the system.