bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constituting and Investigation of Ion-Implanted Protective Layer on NiTi Alloy for Mechanical and Tribological Applications
Authors: Levintant-Zayonts N. , Starzynski G. , Kucharski S. 
Published: August 2024

Abstract
NiTi exhibits an excellent wear resistance, which can be further enhanced by ion implantation. However, there are some limitations to the implantation effects: only a thin layer of about 100 nm can be created. In this paper, the effect of nitrogen ion implantation on the NiTi wear response is investigated. The different loads and durations of tests are taken into account to show that the implanted layer has the most beneficial effect only in a certain range of contact pressure. It was found that the wear volume changes in a non-linear manner with respect to the load and sliding length, for both non- and implanted samples. For the latter, two distinct stages can be distinguished in the wear process: an initial stage characterized by a low wear-rate and a low coefficient of friction, and a second stage in which the wear-rate drastically increases. The duration of the first stage is longer for lower loads. This specific behavior is explained by differences in the hardness distribution, energy dissipation due to the normal load, and differences in the microstructure of the wear tracks. Our results show that the lifetime of NiTi can be improved by ion implantation, thus boding well for applications in harsh environments.
Study of the Influence of Pre-Drilled Holes on Weakening the Rocks and Enhancing the Rate of Penetration
Authors: Abugharara Abdelsalam N. A. , Alwaar Abourawi , Futheiz Ibrahim , Butt Stephen D. 
Published: August 2024

Abstract
Improving the drilling Rate Of Penetration (ROP) is a target for oil and gas drilling companies. However, efficient drilling performance is not only measured by the improvement of ROP, but it is also measured by minimizing the mechanical specific energy, minimizing the bit wear rate, minimizing the NonProductive Time (NDP) impacted by the pre-mature bit wear and failure, as well as by reducing the overall drilling cost. Another approach of improving drilling performance is sought through optimal applications of drilling parameters including sufficient fluid flow rate for efficient hole cleaning and bit ball prevention, applying adequate Weight On Bit (WOB) that induces effective Depth Of Cut (DOC) without negatively inducing the bit wear rate to increase, and at optimal rotary speed. This research focuses on applying various techniques through multi stage drilling and coring in high strength formation using PDC bits and natural diamond impregnated coring bits to investigate potential micro cracks generation. The analysis of drilling and coring data includes evaluation of input drilling parameters such as WOB and rotational speed as well as the output data of ROP, DOC, torque, etc. The drilling experiments were laboratory based using a large lab scale of a fully instrumented drilling simulator. A high strength rocks were drilled, and water flow rate was used. Different applied WOB and rotational speeds were applied. The results of the analyzed data indicated variation in ROP (increasing and decreasing) when drilling different stages at the same conditions of the applied parameters. ROP was increased parallel to the predrilled section, where the ROP was found decreases when drilling the un-predrilled section. Corresponding data of torque also supported the ROP increase vs. which was influenced by possible rock weakened due to possible micro cracks generation in the predrilled section. Data analysis, results, and conclusions are reported.
Dashpot-Enhanced RVE Model for Simulating Bending of Three-Core Submarine Power Cables
Authors: Li Xiao , Jiang Xiaoli , Hopman Hans , Bai Yong , Liu Zhuangjian 
Published: August 2024

Abstract
This study presents a Representative Volume Element (RVE) model for predicting the bending stiffness of three-core submarine power cables used in offshore wind farms. The RVE model, developed with constant curvature and periodic conditions, incorporates a dashpot technique to address stick-slip challenges associated with cable bending. Bending tests were performed on one-core and three-core cables to serve for model calibration and validation, separately. The dashpot coefficient in the RVE is first calibrated through the one-core bending test. Subsequently, the calibrated model is validated using the three-core bending test. This work demonstrates the capability of the dashpot-enhanced RVE in predicting bending stiffness of three-core cables.
On the Performance of a Novel Hinged Type Wave Energy Converter
Authors: Jin Siya , Guo Bingyong , Chen Lifen , Xu Sheng , Yang Kunde 
Published: August 2024

Abstract
This paper aims at carefully studying the performance of a novel two-body hinged wave energy converter (WEC). Two different types of WEC are investigated: a counterpart using the generic two-body hinged-type WEC composed of two cubic floating bodies and a designed novel two-body hinged WEC composed of floating bodies with wave channels. The wave channel consists of two side walls, an inclined base and an end wall connected to the main floating body. Physical tank tests, CFD simulations and WEC-Sim modelling are employed in the study. Validated by the physically obtained data (including wave elevation, torque force, surge force and heave force acting on the body), the CFD modelling is shown to be capable of presenting the hydrodynamic interaction between the wave and the novel body with wave channel. Additionally, unlike the traditional cubic body, the body with wave channel is able to receive the incoming wave to change the mass properties of the WEC. As a result, the resonance frequency of the designed hinged WEC can vary under different wave conditions, leading the WEC device to have a broader wave capture band. Moreover, a CFD numerical wave tank is built to model the interaction between the wave and the hinged-type WEC with expensive computation however. A fast-solving WEC-Sim modelling is, therefore established to simulate the hydrodynamic response of this novel hinged-type WEC. The results show that the designed hinged type WEC with wave channels has better hydrodynamic performance compared to the generic hinged WEC.
Numerical Analysis of Structured Sheet Material in Flexible Oscillating Water Column Wave Energy Converter
Authors: Huang Yang , Idarraga Guillermo , Xiao Qing , Yang Liu , Dai Saishuai , Abad Farhad , Brennan Feargal , Lotfian Saeid 
Published: August 2024

Abstract
To improve the power output and reduce the stress levels for Flexible Wave Energy Converters (FlexWECs), a structured material using a sheet of natural rubber with a specific pattern called NR937 is developed in this research. Mechanical characterisation tests are conducted to determine the material properties, and the YEOH hyper-elastic model is employed to capture the nonlinear behaviour of this material. Fluid-structure interaction simulations are performed for a FlexWEC using a CFD-FEA tool. The responses of the Poly-A-OWC model equipped with both the innovative NR937 material and a conventional sheet of Natural Rubber (NR) are compared, and the deformation of flexible membrane, stress distribution, flow field, and power output are all fully explored. The results indicate that at resonance, the deformation amplitude of the flexible membrane using NR937 is increased by 1.3 times compared to that using NR, while the maximum stress increases by only 12%. Additionally, the peak power output of the Oscillating Water Column (OWC) Wave Energy Converter (WEC) utilizing NR937 is approximately 2.6 times higher than that of the WEC using NR. This suggests that structured sheet materials possess potential for improving the performance of FlexWECs, including increasing power output, reducing stress levels in flexible membrane and extending the service life.
Design Analysis of Shared Mooring for Floating Offshore Wind Farm
Authors: Li Binbin , Wang Chenyu , Yang Lei , Zhao Wenhua 
Published: August 2024

Abstract
The development of wind energy in deeper waters presents numerous advantages; however, floating offshore wind turbines (FOWTs) face challenges, primarily in terms of their higher levelized cost of energy (LCOE) compared to onshore and fixed offshore turbines. To address this, the concept of a shared mooring system has emerged as a potential solution to reduce costs. However, practical application and validation of this concept in real-world engineering projects are yet to be realized. Consequently, there is a lack of design methodology, specialized analytical tools, and industrial rules for the design and analysis of shared mooring systems. This study aims to summarize the latest research efforts in developing a methodology for the design and analysis of shared mooring systems. Various levels of dynamic models, including the spring-mass model, quasi-dynamic model, and fully coupled sub-model, are discussed. A dedicated module for shared mooring analysis has been developed within the in-house software KraKen. The study explores design constraints, considerations, modal characteristics, global performance, transient effects resulting from sudden line loss, adaptability of different mooring line models, and structural redundancy of the entire system. These aspects are examined through numerical simulations and a survey of existing rules. By consolidating these research findings, the authors aim to contribute towards establishing a comprehensive framework for the design and analysis of shared mooring systems of floating wind farm.
Dynamic Response Analysis of Bio-Inspired TSUSUCA DOLPHINPatented
Authors: Chandrasekaran Srinivasan , Patil Basanagouda I. , A. Meher Prasad 
Published: August 2024

Abstract
The devastating impacts of tsunamis on humans and strategic infrastructure for naval defence emphasize the requirements for coastal protection. Further, offshore floating platforms are deployed extensively to accommodate the expanding need for oil and gas exploration and wave and wind energy extraction. They are commissioned for limited applications, making them uneconomical. In the present study, a novel attempt is made to combine the functional aspects of coastal protection with energy harvest. The current study focuses on dynamic response analysis of one such novel platform TSUSUCA DOLPHINPatented to act as a tsunami barrier in addition to a wave energy extracting device. Apart from wave energy extraction, solar panels are placed on the deck for additional energy capture. The design follows a bio-inspired geometry to attract tourists under normal sea states. The dynamic response of the multi-body by considering 2 TSUSUCAs is presented. The suggested platform’s dynamic response under regular and irregular waves is being studied numerically and experimentally. The design’s proposed motion characteristics, notably heave and pitch, aid in the capture of wave energy for a wide variety of wave amplitudes. This allows the TSUSUCA body to move in an oscillating motion in the vertical plane, one of the platform’s critical activities: tsunami protection.
Development and Application of a Digital Tool for Real-Time Corrosion Monitoring and Decision Support in Well Integrity Management
Authors: Wu Bohong , Wang Bei , Shi Shuzhe , Nie Zhen , Chen Yingfeng 
Published: August 2024

Abstract
Well integrity management is essential for preventing well leakage and ensuring the optimal performance of oil and gas wells. Existing downhole monitoring tools are complex to install and unable to monitor the corrosion condition along the wellbore. These drawbacks limit the effective support for well integrity management and increase potential HSE risks.
Therefore, a new digital and visual corrosion management platform was developed to overcome these challenges and enhance well integrity management. This dashboard links to the oilfield database to obtain dynamic real-time data, integrating it with static data through manual integration to form a wellbore integrity database with over 46 types of data. Advanced corrosion rate prediction models were established based on this database, developing modules for single well corrosion rate monitoring, remaining wall thickness and life prediction for tubing, and early warning of corrosion status in oil and gas fields. This dashboard is currently the only tool capable of calculating corrosion rates for gas lift wells, dynamically displaying corrosion risk and integrity parameters for various types of wells, providing support for intelligent decision-making in oil and gas fields. It also offers quick recommendations for material selection through simple parameter input to support wellbore integrity management.
Numerical Investigation of Mooring System and First-Year Ice Ridge Keel Interaction
Authors: Chen Jiaming , Zhou Li , Ding Shifeng , Ding Yi 
Published: August 2024

Abstract
This work focuses on develop a new mooring cable-keel interaction model to investigate the dynamic response of mooring system for moored structures in Arctic regions. Since the ice ridge volume change during failure process of cohesion, it is more practicable to use a constitutive model considering deformation accumulation and stiffness decay in the interaction between slender body and ice ridge keel. A formula for the relationship between the contact index and the porosity between the brash ice is presented, and the breaking condition of the ice ridge keel is described according to the relevant critical state. The simulation results are compared with model test data to verify the accuracy of the new interaction model. The plastic failure mode can be directly applied to predict the ice ridge load on the mooring cable, and the mooring cable gradually breaks the ridge keel as the ridge drifts motion. The result of tension distribution and dynamic response on the mooring cable can provide some significant hints for the design of mooring system for moored structures.
Long Horizontal Slim-Hole Cementing Technologies for Cost-Effective Development in a Middle East Ultra Low Permeability Reservoir
Authors: Nie Zhen , Shi Shuzhe 
Published: August 2024

Abstract
The Sadi ultra-low permeability reservoir accounts for more than 25% geological reserves of a giant Middle East Oilfield. 70 horizontal wells with more than 5000m MD have been planned and the infinite stage cementing fracturing technique are proposed in 1000m-2000m horizontal section for Sadi reservoir cost-effective development. The liner cementing quality in long horizontal section is the key to the success of good zonal isolation and premises of effective hydraulic fracture operation.
To improve the efficiency and performance of 4 1/2″ liner cementing, a comprehensive series of numerical simulation of cementing process and experimental research of core additives have been carried out to overcome slim-hole cementing challenges such as poor centralization, insufficient mud removal or displacement, and low cement bond quality. The cementing operation procedure was optimized including centralizer selection, cementing liquid volume design, Rheological property design and cementing operation parameters. The integrity mechanical model of cement sheath was established so that to design the high efficiency washing space fluid and flexible cement slurry based on experimental results.
By simulating mud removal and cement slurry placement process, integral elastic centralizer and centralization program was recommended, sequence of cementing fluid with appropriate density and volume was determined. the rheology property of Spacers/ Lead slurry / tail slurry was determined in view of the friction resistance hierarchy concept, and variable pumping procedure has been optimized to achieve better effective mud displacement. Meantime, the mechanical properties of the cement sheath was demonstrated by integrity analysis under the condition of multistage fracturing in horizontal section, and concluded that cement sheath shall meet the requirements of Elastic modulus &lt; 6.5GPa, Poisson’s ratio &gt; 0.18, Compressive strength &gt; 24MPa, Tensile strength &lt; 2MPa. In terms of cementing fluid. A new toughening agent was also developed to improve the mechanical property of cement sheath to meet the requirements of infinite stage cementing fracturing operation.
Liner cementing key techniques has been developed to achieve effective zonal isolation and good cement bond quality in challenging long horizontal slim-hole cementing and application in-site horizontal well cementing job and achieved the good cement bond quality, this technology is expected to deliver a successfully optimized liner cementing operation for future horizontal wells cementing.
Deterministic Sea Wave Prediction Based on Radar Images Via End-To-End Deep Learning Methods
Authors: Zheng Yaokun , Lin Zhiliang 
Published: August 2024

Abstract
Deterministic sea wave prediction (DSWP) based on radar images is meaningful in ocean engineering. Achieving accurate and efficient methods for predicting nonlinear waves remains a challenge. In this paper, spatiotemporal reconstruction and prediction based on radar images via deep learning methods are investigated. The radar images are synthetic and based on the 2nd order Lagrange wave model. The Fourier neural operator (FNO), which integrates Fourier transform and deep learning, and ConvLSTM, which is a classical spatiotemporal forecasting network, are tested. The direct prediction approach and multitask learning approach are introduced and evaluated. The results show that the FNO with multi-task learning approach performs effectively in the presence of noise and under multiple wave steepness. The results confirm the feasibility and performance of deep learning method for DSWP based on radar images.
Elastic-Plastic Buckling Analysis of a Ship Circular Hollow Pillar Under Compression and Bending Loads: Analytical Resolution and Comparison to Finite Element Analysis
Authors: Nicolas Aurélien , Conti Fabien 
Published: August 2024

Abstract
Pillars have various applications in ships and maritime structures. They can undergo bending, torsion and compression loads. Their limit state can be determined through finite element analysis, considering their geometric characteristics, material and applied stresses. However, finite element modelling can be less easy to handle than an analytical solution, especially when large numbers of calculations are needed.
In this study, we present the results from 1D analytical analysis considering an initial compression stress and two different moments at each end of the pillar — implying that a transverse force was applied at one end. This represents a typical ship pillar between two consecutive decks.
The physical problem statement consists of the resolution of a first order coupled differential system of four equations. Solving this problem numerically accounting for large displacements and elastic material behavior yields solutions very close to the finite element modelling. We finally developed an elastic-plastic analysis of the same problem. Analytical resolution consisted of the derivation of a moment-curvature law including elastic and perfectly plastic behaviors. To derive this law, compression and moment are applied on a cross section of the beam. In the elastic behavior, bending stress and curvature are related through Young’s modulus and inertia, whereas once yield stress is attained no additional stress can be carried in the yielded surface and a new moment-curvature relationship must be developed: In a given cross section, bending stress varies linearly around the neutral fiber (which position depends on the compression stress and curvature) until yield stress is eventually attained. Above and below the position where the yield stress is attained, bending stress remains constant and equal to the material yield stress.
The full analytical procedure is the following: let us first apply the compression stress in a uniform manner in the beam cross section. Then, curvature is increased step by step, and we let plasticity arise and penetrate from the inner part of the curved beam. Integrating the moment over the cross section at each curvature step allows to build the moment-curvature relationship. Analytical results were compared to finite elements analysis; and turned out to be similar with a discrepancy falling within a few percents for both full and hollow pipes.
Finally, we used the moment-curvature relation that was developed to derive the full elastic-perfectly plastic solution with a numerical model; and compared to FEA results.
Exploring the Use of Field Data to Improve Predictions of Pipeline As-Laid Embedment
Authors: Taner Yasar , Hou Zhechen , Bransby Fraser , Watson Phil , Low Han Eng 
Published: August 2024

Abstract
Reliable prediction of as-laid embedment for surface-laid offshore pipelines is important for predicting seabed resistance during operation. However, the accuracy of existing methods can be limited by various challenges: difficulties in determining representative, very near-surface soil properties (either by field or laboratory investigation), inherent seabed variability including bathymetry, and changing/ complex lay conditions.
Given significant experience across the offshore sector with installing offshore pipelines, this study explores the potential to predict as-laid embedment directly from field cone penetration test (CPT) results. Part of the ARC ITRH Transforming energy Infrastructure through Digital Engineering (TIDE), the installation data for two parallel flowlines from a single project on the Northwest Shelf of Australia are used to show that correlations can be made between cone resistance and pipeline embedment — if the cone data is used appropriately. By comparing the observation based correlations with predictions made using current industry practice, the potential to develop a data informed method to predict pipeline as-laid embedment is demonstrated — with the current study to now be extended to other sites, and (if relevant) to consider parameters other than cone resistance to improve the approach.
Validation of a Time Domain Panel Code for Prediction of Impulsive Wave Loads on Container Ships
Authors: van Walree Frans , Grin Rob 
Published: August 2024

Abstract
The focus of the paper is on the prediction of wave loads experienced by a 20kTEU container ship. The principles of the potential flow panel method to predict motions and loads are briefly described. A description of scale model tests is given. A number of validation cases are discussed, whereby experimental and simulated time traces and frequency spectra of accelerations, shear forces, torsion and bending moments in regular and irregular waves are compared. Particular attention is paid into the prediction of whipping and springing phenomena.