bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Applicability of Risk-Based Methods to Optimize Inspection Costs With Focus on a Hydrogen-Fueled Fishing Vessel
Authors: Giannini Leonardo , Salzano Ernesto , Ustolin Federico , Paltrinieri Nicola 
Published: August 2024

Abstract
In an era marked by a growing effort towards environmental sustainability, the development of the hydrogen value chain is crucial for the transformation of the energy landscape. From road transport to aviation and maritime applications, numerous investments and ongoing projects aim at implementing clean hydrogen solutions to reshape entire industries. The spread of hydrogen technologies, however, comes with a rising demand for specific and standardized inspection plans and maintenance activities that are suitable for equipment operating in hydrogen environments. For this reason, a number of critical challenges do emerge. Some main issues of such innovative and environmentally compatible alternatives (i.e., hydrogen-fed fuel cells and hydrogen combustion engines) involve in fact the lack of operational experience and the inexistence of tailored standards and guidelines specifically conceived for hydrogen systems. This may result in a tendency to implement over conservative risk-reducing measures, thus leading to continuous inspection activities and unsustainable associated costs. In fact, an over-conservative risk threshold may imply economic burdens and a competitiveness loss for hydrogen technologies, potentially resulting in the inhibition of their market penetration potential. The current work delves into this problem by addressing the main steps of a cost-benefit analysis based on risk-informed inspection strategies [1] and using a hydrogen-fueled fishing vessel as a practical example, highlighting hazardous scenarios involving the storage system, the costs associated with a hydrogen unwanted release and the measures — inspection and preventive maintenance — that aim at minimizing its likelihood. Through this lens, this paper outlines potential strategies to achieve an optimization of costs and minimization of risk by optimally scheduling inspection procedures, with the idea of supporting the shift towards sustainable energy solutions.
Investigation on Semi-Analytical Solution of Diffracted Wave Field Caused by a Bottom-Mounted Block
Authors: Wang Zerun , Feng Aichun 
Published: August 2024

Abstract
A number of marine structures can be represented by bottom-mounted blocks when analyzing the diffracted wave field. In this paper, the method of domain decomposition and separation of variables are used to derive the velocity potential of diffracted wave field by a bottom-mounted block in a semi-infinite tank. The semi-analytical solutions are compared with the free surface elevation RAO of a block in open waters obtained by commercial software WAMIT, and good agreement is reached. The present solution can be applied as benchmark to verify the results obtained by other numerical methods.
Employing an Asymmetrical Anchoring Solution for Rigid Flowline Riser System Adopting Single Torpedo Piles
Authors: Grevet Simon , Bianco Bruno , Maior Steve , Volpi Eduardo , Genzani Rachel , Solano Rafael F. , Pavone Diego 
Published: August 2024

Abstract
This paper introduces the technical pipeline anchoring solution deployed for rigid flowlines of the Buzios field.
Based on the usual combination of an anchoring pile, a chain and an In-Line Anchor mounted as part of a rigid flowline, this solution stands out on two accounts: the use of torpedo piles, and an asymmetrical configuration with a single fixed point.
This paper addresses the technical challenges associated to it in terms of flowline design in order to guarantee the robustness of the system.
Chain slack management stood as the most critical challenge, due to the inherent extra chain length needed to connect the torpedo pile to the ILA, with the relative angle between the chain and the flowline coming second.
Although one might surmise the design to be governed by the extreme values of these parameters, the analyses carried out demonstrated specific limit states to be occasionally maximized at intermediate values instead, thus requiring more scrutiny and precision in the load cases matrices.
This paper also discusses the importance of properly implementing and modelling the ILA in global flowline models.
Lastly, the benefits of this new solution are discussed, in terms of how it improved installation requirements and overall project readiness.
Numerical Investigation of Vortex-Induced Motions (VIM) on a Semi-Submersible Floating Offshore Wind Turbine
Authors: Yin Decao , Passano Elizabeth , Berthelsen Petter Andreas 
Published: August 2024

Abstract
Vortex-induced motions (VIM) adversely affects the structural integrity and performance of floating offshore wind turbines (FOWT). These motions can impart extreme loads and fatigue stresses on the mooring lines, cables, and other vital substructures, including the nacelle. While semi-submersible platforms with multiple columns are susceptible to VIM, the comprehensive understanding of this phenomenon remains elusive. Historically, model testing has been the primary approach, primarily focused on oil and gas platforms, thereby introducing inherent scaling effects, including Reynolds number effects.
This paper introduces a novel numerical investigation into the VIM behavior of a semi-submersible floater named ‘INO WINDMOOR’. Employing semi-empirical time-domain vortex shedding loads on the platform’s columns, we rigorously explored the VIM responses across a spectrum of current speeds and incident angles.
Our study conclusively demonstrates the presence of VIM in the operational environment of FOWT and underscores the paramount importance of integrating VIM considerations into the design process. This research contributes significantly to advancing our comprehension of VIM effects on semi-submersible FOWT systems, ultimately informing safer and more efficient offshore wind energy solutions.
Utilization of Micro-Annuli Characterization Techniques on Wellbore Samples; Visualization and Permeability Test
Authors: Opedal Nils , Feneuil Blandine , Larsen Idar , Taghipour Ali , Wiggen Even , Skorpa Ragnhild 
Published: August 2024

Abstract
Cement is placed in the annulus between the casing(s) and the surrounding formation rock to ensure no migration of fluids form through the barrier. However, during the operational lifetime of a well changes of pressure and / or temperature lead to extra stresses inside the casing. These stresses can lead to expansions and / or contraction of the casing, with subsequent extra stresses on the surrounding cement sheath. These stresses can result in debonding between the materials or the formation of fractures along the material interfaces or through the material itself. Assessment of the cement is crucial in order to sufficiently manage the integrity of the well. The ideal assessment should consist of 1) a proper visualization of both the sample and fracture geometry, 2) comparison with logging and 3) permeability measurements of the sample/specimen.
This paper describes a study where we have used a unique downscale wellbore cell to mimic the behavior of casing-cement-rock specimens. The specimen was exposed to inner casing pressure cyclic changes and the effect of these cyclic changes are measured using pulse-echo and pitch-catch ultrasonic tool to assess the cement-casing debonding. Furthermore, the specimens are visualized using X-ray CT, and finally the changes in permeability are tested.
An Analysis Method for Fatigue Dynamic Reliability of Ship Structure
Authors: Zhen Chunbo , Zhou Qingwan , Zhang Runze , Xing Shizhu 
Published: August 2024

Abstract
In this paper, the dynamic fatigue reliability analysis method is used to evaluate the fatigue damage of ship structure. Firstly, the limit state equation is established according to the stress strength interference method of fatigue dynamic reliability. Then, according to the characteristics of external load on ship structure, the concept of equivalent stress range and its calculation method for the whole service life of ship structure are given. The time-varying degradation model of fatigue strength is determined according to the characteristics of structural materials, and then a dynamic fatigue reliability analysis method of ship structure is proposed. Finally, taking a bulk carrier as an example, the equivalent stress range of typical hot spots is determined by the direct calculation method of spectral analysis, the structural dynamic reliability and failure probability are calculated, and the fatigue reliability characteristics of hot spots are given. The example results show that, the parts with large fatigue damage have high fatigue failure probability in the early stage of ship service.
Flow-Induced Vibrations of a Square Cylinder With Rigid Upstream Splitter Plate
Authors: Bhatt Dhyey , Nandipeta Vijay Krishna , Joshi Vaibhav 
Published: August 2024

Abstract
Flow across geometries of non-circular cross-section is encountered in many applications such as buildings and offshore semi-submersible columns. In particular, columns of semi-submersibles with square cross-section are subjected to complex ocean currents which could lead to flow-induced vibrations. The possibilities of resonance-type response (vortex-induced vibrations) along with motion-induced instability-type response (galloping) has been observed for such cases, which could be detrimental to the structural integrity. Therefore, it is imperative to control these unwanted oscillations. One possibility is the introduction of a rigid splitter plate on the upstream side of the structure, which has been found to suppress vibrations in case of a circular cross-section. The current study aims to explore this effect by considering a splitter plate of length equal to the side of a square cylinder. A two-dimensional stabilized Petrov-Galerkin variational formulation is utilized to solve the Navier-Stokes equations on an arbitrary Lagrangian-Eulerian moving mesh framework. The rigid cylinder is elastically mounted on a spring and is free to oscillate in the cross-flow direction. The gap between the cylinder and the trailing edge of the splitter plate is varied in the range of 0 to 3D, with D being the side of the cylinder. The study is conducted at Reynolds number of 200 and a mass ratio of 10 in which the galloping-type of instabilities are expected. The results may pave the way for possible passive suppression of flow-induced vibrations for marine structures with square cross-section.
Invasive Marine Species and the Decommissioning of Offshore Oil and Gas Installations: Challenges and Sustainable Management
Authors: de Lima Fasca Hanna , Salomon Paulo Sergio , Costa José Lino , Carneiro Paulo Roberto F. , Couto Thiago Correia , Cordeiro Marcelle Cândido , de Souza Marcelo Igor Lourenço 
Published: August 2024

Abstract
Oil and natural gas (O&G) industries are significant players in the global economy. The lifecycle of O&G installations has reached an age at which many must be decommissioned. Biological invasion is the process by which a species is introduced into a new geographic region caused by the interference of human activities. Scientists and policymakers have identified invasive species as a significant threat to marine ecosystems affecting biodiversity. Today, O&G habitats and invasive species represent only 9% of biodiversity studies relative this field. We provide an overview of invasive species linked to decommissioning operations worldwide and emphasize the Brazilian context to support the sustainable management of decommissioning operations. O&G facilities have contributed to the spread of invasive species, such as the bryozoan Watersipora subatra in Santa Barbara Channel (California) and the sun coral species Tubastraea coccínea and T. tagusensis in the Gulf of Mexico and the Brazilian coast. The Brazilian case highlighted in this study shows several platforms to be decommissioning, and the presence of sun coral along the coast which poses biodiversity in risk. Measures must be taken to control the sun coral dissemination and some recommendations were made in this study to support futures studies.
Investigation of Water Surface Fluctuation and Flow Velocity Inside a Floating Closed Flexible Membrane Fish Cage Under Forced Oscillation Experiment
Authors: Dong Shuchuang , Zhou Jinxin , Han Yunzhou , Bai Shenyi , Kitazawa Daisuke 
Published: August 2024

Abstract
A floating closed fish cage is required for environmental issues such as SDGs (Sustainable Development Goals). The flexible membrane fish cage generally exhibits a reduced motion response. However, the sloshing-induced fluctuations in the internal water remain unclear, despite their critical importance for fish welfare and waste and bait removal in closed fish cages. In the present study, we investigated the water flow velocity, water surface level changes, and fish school behavior in a closed flexible fish cage by forced oscillation experiments. The target fish cage is circular, representing a real fish cage with dimensions of 25 m in diameter, a sheet height of 12.5 m, and a free board of 2.5 m. A 1/50 scale model was designed and attached to a forced oscillation device. To analyze the internal water movement in waves, we reproduced pitch motion using the forced oscillation device. We measured pitching moment, and flow velocity at a depth of 6 cm and 12 cm below water surface, and water level fluctuations on both sides and in the center of the fish cage. 23 zebrafish Danio rerio were placed inside the fish cage, and their behavioral characteristics were observed.
As a result, the pitching moment exhibited an increasing trend with increasing pitch oscillation amplitude, peaking at a pitch oscillation period of 1.05 s. Simultaneously, the internal water surface exhibited pronounced and highly nonlinear fluctuations at the period of 1.05 s. The internal water level at the sides followed a similar trend in both magnitude and change tendency, showing symmetry. The water level measured at the center was significantly lower than that on the sides. Within the measurement range, the flow velocity increased as the oscillation amplitude increased, reaching a maximum of 10.8 cm/s. Despite the complexity of zebrafish fish school behavior under forced oscillation conditions, the fish tended to aggregate in the deeper parts of the net cage. Furthermore, the presence of fish had minimal impact on the pitching moment results. Overall, these findings are expected to provide references for the design and operation of the closed fish cage system.
Study on Wear and Breakage Estimations for Single Point Mooring Chain of Offshore Floating Platform
Authors: Katayama Toru , Hasunuma Ryoya , Yamamoto Yusuke , Taniguchi Tomoki , Fukute Yusuke , Goto Masahiro 
Published: August 2024

Abstract
In this study, a practical estimation method for wear and breakage of mooring chain is investigated. In the method, mooring tension and sliding angle between mooring links are estimated from measured buoy’s motion. At the towing tank of Osaka Metropolitan University, by using motion of a small scale model of buoy with single point slack moored for 75m sea depth, its mooring tension and its motion of the mooring chain are measured in irregular waves. From the results, it is found that the mooring tension at the mooring point is correlated with the vertical acceleration on the buoy regardless of significant wave height and period. Furthermore, it is also found that the sliding velocity at the mooring point is proportion to the pitching angular velocity of the buoy. These results indicate that the wear condition and the breakage possibility at mooring point can be estimated by measuring buoy’s motion. In addition, the feasibility of the wear and breakage possibility estimation for whole mooring chain by using an numerical simulation assimilated to the measured data is investigated.
Development of Calibrated Deterministic Design Approach for Design and Assessment of Offshore Structures Exposed to Environmental Loading
Authors: Tychsen Jesper , Zeeberg Allan , Nielsen Jørgen S. , Cholley Jean-Marc 
Published: August 2024

Abstract
The integrity of offshore structures is commonly demonstrated by proving the structure has sufficient strength to pass code-based strength checks (limit states). Hence, the reliability of any structure exposed to environmental loading from waves, wind, etc. is inherently linked to the requirements of codes and standards.
Design requirements in European codes and standards for onshore structures are commonly calibrated to link code compliance to acceptance criteria expressed in terms of target annual probability of collapse. However, this is not generally the case for codes and standards used in the offshore industry to verify structural integrity and so designers, asset owners etc. of offshore installations will usually not know the failure probability of their code compliant structures. In [4] the common design criteria for the most important offshore code, ISO19902 [5] has been (re-)assessed, and a huge variability across a range of different failure mechanisms is found. In other words, the reliability of code compliant structures is far from uniform: it depends upon the structural configuration, the environment at the installation site, and the location (within the structure) of the weakest failure mechanisms. The result is that structures either have a too low or too high failure probability and cost-benefit is not optimized as a few weak links may control integrity, while major parts of the structure are relatively too strong.
To mitigate the above, we have used a newly developed SRA model [3] that accounts for non-breaking, spilling-breaking and plunging-breaking 3D waves, to calibrate a deterministic engineering approach to align with user defined target failure probability. The work is described in the present paper.
Data-Driven Prediction Method for Remaining Useful Life of Rolling Bearings
Authors: Xu Shiyi , Li Tianyun , Zhang Yao 
Published: August 2024

Abstract
As a critical component of maritime vessels, bearings face various extreme environments and challenges, making them susceptible to high loads and adverse working conditions. Predictive analysis of bearing life allows maritime maintenance teams to take proactive measures, such as actively replacing or repairing damaged bearings, thereby preventing sudden failures and ensuring the reliability and stability of the vessel. To achieve accurate prediction of the remaining life of rolling bearings, this study proposes a novel two-stage strategy for life prediction. In the first stage, time-domain and frequency-domain features are extracted from the original vibration signals of rolling bearings. Subsequently, an adaptive feature selection method autonomously determines the dimensions of the feature subset, identifying the optimal feature subset. In the second stage, the optimal feature subset is input into the proposed ResNet-BiLSTM-ATT model for predicting the remaining useful life of bearings. The proposed prediction strategy has been validated on two public datasets. The results indicate that the proposed data-driven prediction method can accurately predict the remaining life of rolling bearings. This study holds significant practicality in ensuring navigation safety, optimizing maintenance management, and reducing energy wastage.
Assessment of Power Generation Systems With and Without Carbon Capture on Offshore Hydrocarbon Processing Facilities
Authors: Tan Jaime HuiChoo , Lee Chong Jin , Mantry Ravi Kumar 
Published: August 2024

Abstract
There are very few offshore hydrocarbon processing facilities in operation that have implemented combined-cycle power generation systems, and this power scheme deserves more serious consideration and adoption due to its positive effect on carbon reduction. In this study, assessment is made of power generation schemes based on gas-driven power generation system, steam-driven power generation system and combined-cycle power generation system for an example floating production, storage and offloading (FPSO) platform design, to compare the engineering design, fuel gas consumption, equipment weights, and carbon dioxide (CO2) emissions associated to each power generation system. It is found that the combined-cycle power generation system improves energy efficiency, reduces fuel gas consumption and in turn reduces CO2 emissions. Further, potential implementation of an offshore carbon capture system for separating CO2 from the gas turbine flue gases using a proprietary amine absorption technology, is presented. This paper recommends integrating combined-cycle power generation scheme and post-combustion carbon capture on the gas turbine exhausts for reducing the carbon footprint of the power generation system on the facility. Carbon capture of the process waste gas incinerator exhausts can further achieve the overall facility net-zero carbon emissions target, however this aspect is not in the scope of this paper.
A Global Shape Function Method for Dynamic Analysis of Mooring Systems
Authors: Liu Fushun , You Shiji 
Published: August 2024

Abstract
A new global shape function (GSF) based dynamic analysis method for mooring systems of floating structures is proposed, aiming at securing a robust solution to the existing trade-off issue between accuracy and efficiency. Distinguished from the widely used methods, the GSF method is initially derived from Hamilton’s principle, and then the global stiffness matrices are directly constructed under the consideration of global nonlinear strain with the capability of high-computational efficiency, owing to the unemployment of transformation matrices. Each mooring line is discretized into elements using Lagrangian shape functions, which deliberately consider both the Morison forces and the time-varying global stiffness matrices in a set of control equations. The accuracy of the proposed GSF method is firstly verified by experimental results published. Results show that the GFS method has the ability to achieve more accurate results than the solutions of the rod theory applicable to dynamic analysis of the mooring system. Furthermore, an OC4 floating wind turbine is employed to demonstrate at least 35% efficiency improvement than the results by the rod theory, while maintaining the same accuracy. This study sheds light on potential applications in marine engineering.