bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation on Fatigue Life Prediction of Riveted Cantilever Beam Using FEA Approach
Authors: Siva Sankara Rao Yemineni , Mallikarjuna Rao Kutchibotla , Subba Rao V. V. 
Published: October 2021

Abstract
Different structural elements of automobiles, ships, aircraft wings and fuselages, turbines, nuclear reactors, and other machine components are susceptible to variable loading condition. Due to this type of loading situation all the mentioned structures are undergone to the formation of internal cracks, these cracks will be grown and eventually lead to the failure of the structures. Hence, the fatigue phenomenon due to variable loading conditions is a major threat and has come into address with the technological development that happening is now a days. To avoid the failure of structures due to fatigue loading condition structures are provided with different fasteners like rivets, bolts, tack welds, etc. In this study, the structures analyzed are cantilever beams, the fasteners considered are rivets, the loading considered for analysis is fully reversed cyclic loading, and the analysis considered is the fatigue analysis, the mode of analysis is a simulation using FEA software named ANSYS R19.2 WORKBENCH software. The variable parameters considered are rivet diameter, load, and coefficient of friction at the common interface of riveted specimens. Here in this analysis, the beam dimensions are kept constant. Besides, in this study, the comparison of fatigue life for solid and riveted cantilever beams of identical dimensions is presented. The material considered for the rivets and beams is aluminum alloy.
Engineering Critical Assessment of Triple-Point Flaws in Mechanically Lined Pipes
Authors: Pépin Aurélien , Tkaczyk Tomasz , Abderrazak Riadh 
Published: October 2021

Abstract
There is increasing demand for subsea transport of well-produced fluids through corrosion resistant pipelines such as stainless steel or bimetallic pipes. The latter are made of carbon steel (CS) pipe and a thin (typically 3.0 mm thick) internal layer of corrosion resistant alloy (CRA) such as 316L, 625, 825 or 904L. The CRA and CS layers are adhered either metallurgically or mechanically by a means of an interference fit. Although less mature than other products, mechanically lined pipes (MLP) are more readily available and economical than both stainless steel or hot-roll bonded (HRB) metallurgically clad pipes. One of the gaps that remains to be filled relates to a reliable assessment method for confirming the MLP integrity during offshore installation and subsea service.
The CRA liner in MLP is metallurgically bonded to CS at pipe ends by overlay welding, typically deposited using alloy 625 consumable. At the triple-point interface between the liner, overlay and host pipe, cracks may initiate from fabrication flaws and grow during installation or in service. Therefore, the engineering critical assessment (ECA) should be carried out to evaluate the risk of triple-point cracks breaching the CRA layer at any stage of the pipeline’s life cycle. Currently, no recognised ECA approach exists to allow completing such an assessment.
Therefore, a bespoke integrity assessment procedure has been developed and validated both numerically and via laboratory testing. This paper outlines the ECA procedure for triple-point flaws in subsea MLP pipelines, which is undertaken through a combined analytical and numerical calculation and small-scale fracture testing. Fatigue crack growth due to cyclic loading is estimated using a geometry-specific stress intensity factor (SIF) solution derived by finite-element analysis (FEA). Ductile tearing during fracture load events is quantified by small-scale fracture testing on specimens with a representative geometry, designed to match the crack tip constraint of triple-point cracks in MLP.
Assessment of Numerical Modeling Tools for the Prediction of Ship Performance in Ice
Authors: Lau Michael 
Published: October 2021

Abstract
This paper provides a general review of available models used in the NRC-OCRE (National Research Council – Ocean, Coastal and River Engineering) that could be used to support the assessment of a ship’s performance in ice conditions. The models were separated into three main categories: empirical, numerical and real-time, and reviewed in terms of key strengths and weaknesses. A general overview of the modelling categories and specific models within each category is given. Within each modelling category, specific models were compared to outline the key features of both the independent models and the modelling category itself. A representative model within each category and sub-category was selected and used to present the output for a given scenario. This enabled a demonstration of output capabilities for each modelling category. It also provides the reader with additional information pertaining to the input requirements and validation for the selected models. A discussion of the integration of an ice loading model into an existing ship simulation framework is included. A specific case was reviewed in which a successful integration had occurred and was documented. This allowed for demonstration of a process that could be followed for updating one’s numerical modelling capabilities. Based on this review, guidance was provided in terms of selecting a numerical tool to extend current ship performance modelling capabilities to consider ice operations. Each modelling category and sub-category has a unique set of advantages and disadvantages. These should be considered in detail to ensure that the numerical model(s) selected are optimal in terms of their ability to assess desired scenarios and interface with existing software.
Design and Research of Offshore Oil Spill Removal Ship With Variable Angle of Attack
Authors: Ou Qibin , Yang Jin , Zhang Zhenxiang , Liu Luo , Zhang Yichi , Qu Ximo 
Published: October 2021

Abstract
With the continuous development of the global economy and industry, and gradually expand the size of offshore oil exploration and transportation, the possibility of oil field leakage, damage of offshore tanker, oil leakage of the offshore ship and the oil spill is increasing continuously, and the harmfulness is increasing continuously. It has seriously polluted the Marine environment and destroyed the ecological balance, and seriously wasted the oil resources. Therefore, this paper developed a kind of offshore oil spill removal ship which can quickly, accurately, and effectively recover oil spill. This paper designs an offshore oil removal device with a variable Angle of attack. Through the use of Rhino and SolidWorks modeling software for the three-dimensional overall design. The variable Angle of attack offshore oil spill removal ship can be divided into seven major systems, which are the main hull of the variable angle of attack, the side hull, the oil suction, and deoiling rollers, the oil collecting groove and oil collecting chamber, the oil baffle, the steering platform, the communication equipment, the propulsion equipment, the main hull, and the external ship docking equipment. At the same time, the new type of offshore oil absorption material is installed on the double roller oil absorption mechanism, and each component system of the offshore oil removal ship is assembled. In this paper, the design of a variable Angle of attack offshore oil spill removal ship can provide a reference for the research and design of a new offshore oil spill treatment device.
Numerical Investigation of a Variable-Shape Buoy Wave Energy Converter
Authors: Shabara Mohamed A. , Zou Shangyan , Abdelkhalik Ossama 
Published: October 2021

Abstract
A novel Variable-Shape Buoy Wave Energy Converter (VSB WEC) that aims at eliminating the requirement of reactive power is analyzed in this paper. Unlike conventional Fixed Shape Buoy Wave Energy Converters (FSB WECs), the VSB WEC allows continuous shape-changing (flexible) responses to ocean waves. The non-linear interaction between the device and waves is demonstrated to result in more power when using simple, low-cost damping control system. High fidelity numerical simulations are conducted to compare the performance of a VSB WEC to a conventional FSB WEC, of the same volume and mass, in terms of power conversion, maximum displacements, and velocities. A Computational Fluid Dynamics (CFD) based Numerical Wave Tank (CNWT), developed using ANSYS 2-way fluid-structure interaction (FSI) is used for simulations. The results show that the average power conversion is significantly increased when using the VSB WEC.
A Review of DNVGL-RP-F105 Fatigue Assessment Model or Why My Free Span Has Not Failed
Authors: Caruso Mário 
Published: October 2021

Abstract
The objective of a free span fatigue assessment is to provide a rational criterion to evaluate the long-term integrity of a free spanning pipeline, to which DNVGL-RP-F105 was developed. The Recommended Practice has a long history. Guideline 14, the foundation document to it, was released in 1998. The guidelines of the DNVGL-RP-F105 were gradually adopted by the industry for free spans analysis, and even API 1111 makes direct reference to it. Today, DNVGL-RP-F105 is the de facto Vortex Induced Vibration analysis guide for all applications where small number of bending driven modes are expected to be excited, overstepping its original purpose of free spanning pipelines and providing guidance when no other source exists.
With such a long history, it is easy to forget the basis for the Recommended Practice fatigue model and obtain results that do not match expectations. A prime example is when assessing a free span based on survey and the fatigue life capacity calculated following the Recommended Practice is much smaller than the actual exposure time. In this situation one may ask “why my free span has not failed?” and conclude that the Recommended Practice is either too over conservative or plainly wrong.
This paper reviews some key aspects of the DNVGL-RP-F105 fatigue model and explore their implication to fatigue design and assessment. And it hopes to clarify why your free span has not failed even when you expected it to.
Sloshing Effects on FLNG and LNGC Side-by-Side Offloading
Authors: Koo Bonjun , Auburtin Erwan , Kim Hyoungchul 
Published: October 2021

Abstract
A side-by-side moored offloading configuration has relatively stronger hydrodynamic and mechanical interactions compared to a tandem moored offloading configuration. For instance, due to the narrow gap between FLNG and LNG Carrier, the trapped water resonance induces higher relative motions between the FLNG and LNG Carrier. In addition, due to the partial filling conditions during the offloading operations, the sloshing loads excite ship motions which induce higher loading on the offloading arms. In this research, a time domain sloshing-ship motion coupling analysis module has been developed for analyzing interactions of the side-by-side moored multiple floating platforms. This paper presents the numerical modeling, the validation analysis results, and the sloshing-ship motion coupled effects on the side-by-side offloading analysis.
Numerical Ocean Wave-Basin (NOW): A Numerical Solution for FSRU Mooring Design Analysis
Authors: Kim Jang , Jang Hyunchul , Lim Ho-Joon , Lai Lawrence , Latifah Arnida , Auburtin Erwan , Tcherniguin Nicolas , Petrie Francois 
Published: October 2021

Abstract
A numerical solution is proposed for the design analysis of the mooring system of an FSRU in shallow water. Previously. such analysis relied on second-order diffraction theory with viscous damping empirically calibrated from physical model tests. However, both experimental and theoretical methods had to introduce uncertainties in the predicted mooring load because of their physical and theoretical limitations. A complicated procedure had to be introduced to derive design loads considering the uncertainties and limitations. The proposed numerical solutions are developed to minimize those uncertainties by introducing the state-of-the-art numerical tools to accurately model the flow field near the FSRU and the surrounding wave field. A CFD-based numerical wave basin, MrNWB, and a potential-based higher-order Boussinesq wave model, HAWASSI, are coupled together to simulate the near- and outer-field free-surface flows around the FSRU hull.
This paper describes the framework of the proposed numerical method, followed by preliminary verifications of the accuracy and effectiveness of the proposed solution. A benchmark model test of an FSRU moored in a shallow sloping beach is used to validate the generation of the low-frequency wave and the slow-drift motion of FSRU from CFD simulation. The numerical results show significant improvement in the low-frequency FSRU responses compared to the conventional theoretical methods.
Independent Design Verification of Deepwater SCRs for the Application in South China Sea
Authors: Yang Hu , Cheng Yongming , Xu Fanli , He Ning 
Published: October 2021

Abstract
Through nearly 30 years of design and implementation, Steel Catenary Risers (SCRs) have been found to have the advantages of relatively low cost and good adaptability to floating platform’s motion. SCRs have been selected as the production and export riser solution for Lingshui 17-2 (termed LS17-2) field in South China Sea, which consists of a subsea production system, a deep-draft semi-submersible, and an export riser/pipeline. This paper investigates independent design verification of deepwater SCRs for the application in South China Sea.
This paper first introduces a SCR system for LS17-2 project. The field for this project is located in northern South China Sea, with water depth of 1220m to 1560m. This paper describes the design verification methodology, procedure, riser computer modelling, extreme challenges, findings, and technical discussions. The independent design verification includes riser sizing, adjacent riser interference, cathodic protection, dynamic strength analysis, Vortex-Induced Vibration (VIV) analysis, wave motion fatigue analysis, semi-submersible Vortex-Induced Motion (VIM) fatigue analysis, and riser installation. Sensitivity study was carried out to demonstrate the accuracy of the results and the robustness of the riser design.
SCR designs are extremely sensitive to environmental loading and the motion characteristics of a host platform. The independent design verification shows that the riser governing location of global performance is at the riser Touch Down Point (TDP) region. Compression forces in an SCR touchdown area can be caused by extreme or survival load cases. Among the fatigue damage sources, fatigue damage contributions are dominated by wave motion, VIM and VIV.
This paper finally summarizes the findings from the independent verification work. It concludes that the SCR system design for LS17-2 development meets the requirements of API 2RD design code.
Uncertainty in Collapse Strength Prediction of Sandwich Pipelines
Authors: Bhardwaj U. , Teixeira A. P. , Guedes Soares C. 
Published: October 2021

Abstract
This paper assesses the uncertainty in the collapse strength of sandwich pipelines under external pressure predicted by various strength models in three categories based on interlayer adhesion conditions. First, the validity of the strength models is verified by comparing their predictions with sandwich pipeline collapse test data and the corresponding model uncertainty factors are derived. Then, a parametric analysis of deterministic collapse strength predictions by models is conducted, illustrating insights of models’ behaviour for a wide range of design configurations. Furthermore, the uncertainty among different model predictions is perceived at different configurations of outer and inner pipes and core thicknesses. A case study of a realistic sandwich pipeline is developed, and probabilistic models are defined to basic design parameters. Uncertainty propagation of models’ predictions is assessed by the Monte Carlo simulation method. Finally, the strength model predictions of sandwich pipelines are compared to that of an equivalent single walled pipe.
Nonlinear Fourier Analysis for Shallow Water Waves
Authors: Osborne Alfred R. 
Published: October 2021

Abstract
I consider nonlinear wave motion in shallow water as governed by the KP equation plus perturbations. I have previously shown that broad band, multiply periodic solutions of the KP equation are governed by quasiperiodic Fourier series [Osborne, OMAE 2020]. In the present paper I give a new procedure for extending this analysis to the KP equation plus shallow water Hamiltonian perturbations. We therefore have the remarkable result that a complex class of nonlinear shallow water wave equations has solutions governed by quasiperiodic Fourier series that are a linear superposition of sine waves. Such a formulation is important because it was previously thought that solving nonlinear wave equations by a linear superposition principle was impossible. The construction of these linear superpositions in shallow water in an engineering context is the goal of this paper. Furthermore, I address the nonlinear Fourier analysis of experimental data described by shallow water physics. The wave fields dealt with here are fully two-dimensional and essentially consist of the linear superposition of generalized cnoidal waves, which nonlinearly interact with one another. This includes the class of soliton solutions and their associated Mach stems, both of which are important for engineering applications. The newly discovered phenomenon of “fossil breathers” is also characterized in the formulation. I also discuss the exact construction of Morison equation forces on cylindrical piles in terms of quasiperiodic Fourier series.
Suction Caissons as Multipod OWT Foundations in Clay: Investigation of Loading Rate Effects
Authors: Antoniou Maria , Kourkoulis Rallis , Gelagoti Fani , Anastasopoulos Ioannis 
Published: October 2021

Abstract
The paper elaborates on the bearing mechanics of suction caissons serving as the foundation system of offshore wind turbines (OWTs) supported on jacket structures. As axial loading governs foundation design in this configuration, the study proceeds to a numerical investigation of the tensile load carrying capacity of a suction caisson in clay through a series of coupled pore fluid diffusion — effective stress analyses with a hypoplastic constitutive model. The latter allows for the quantification of loading rate effects on the amount of negative excess pore pressures (passive suction) generated within the confined soil plug and their contribution to uplift caisson resistance. Based on these results, a simplified uncoupled procedure is employed to account for loading rate effects in the performance-based design of an 8MW OWT founded on a Suction Bucket Jacket (SBJ).
Investigation of Near-Field Temperature Distribution in Buried Dense Phase CO2 Pipelines
Authors: Olugunwa Babafemi , Race Julia , Yurtseven Ahmet , Tezdogan Tahsin 
Published: October 2021

Abstract
Buried pipelines transporting dense phase Carbon dioxide CO2 are crucial to carbon reduction and climate change mitigating technologies such as Carbon Capture and Storage (CCS) and Carbon Capture Utilization and Storage (CCUS). One of the major challenges for optimum pipeline operating conditions is to avoid phase change of the compressed CO2 and maintain temperature and pressure above the critical point throughout the pipeline route. A suitable pipe-soil heat transfer model during design can mitigate this challenge. However, variations in annual ambient temperatures, ground temperature at pipeline burial depth and soil temperature profile behaviors with seasonal climatic conditions especially during winter and summer periods also affect the heat transfer process between the soil burial medium and the CO2 pipeline. Assuming steady state, this paper investigates the nearfield temperature distribution up to 3m lateral distance away from a buried dense phase CO2 pipeline by numerical simulation with a two-dimensional pipe-soil heat transfer model at a burial depth of 2.3m to pipe center using a finite volume computational code. Results show that thermal parameters such as thermal conductivity and the soil temperature profile influence the heat exchange between pipe walls and porous soil medium. Consequently, this study shows that the near-field temperature distribution and effect of heat around a buried CO2 pipeline diminishes with distance and burial depth further away within the immediate vicinity of the pipeline.
Software-in-the-Loop Combined Machine Learning for Dynamic Responses Analysis of Floating Offshore Wind Turbines
Authors: Chen Peng , Hu Changhong , Hu Zhiqiang 
Published: October 2021

Abstract
Artificial intelligence (AI) brings a new solution to overcome the challenges of Floating offshore wind turbines (FOWTs) to better predict the dynamic responses with intelligent strategies. A new AI-based software-in-the-loop method, named SADA is introduced in this paper for the prediction of dynamic responses of FOWTs, which is proposed based on an in-house programme DARwind. DARwind is a coupled aero-hydro-servo-elastic in-house program for FOWTs, and a reinforcement learning method with exhaust algorithm and deep deterministic policy gradient (DDPG) are embedded in DARwind as an AI module. Firstly, the methodology is introduced with the selection of Key Disciplinary Parameters (KDPs). Secondly, Brute-force Method and DDPG algorithms are adopted to changes the KDPs’ values according to the feedback of 6DOF motions of Hywind Spar-type platform through comparing the DARwind simulation results and those of basin experimental data. Therefore, many other dynamic responses that cannot be measured in basin experiment can be predicted in good accuracy with SADA method. Finally, the case study of SADA method was conducted and the results demonstrated that the mean values of the platform’s motions can be predicted with higher accuracy. This proposed SADA method takes advantage of numerical-experimental method, basin experimental data and the machine learning technology, which brings a new and promising solution for overcoming the handicap impeding direct use of conventional basin experimental way to analyze FOWT’s dynamic responses during the design phase.
Experimental Study of Combined Wave and Ice Loads on a Fixed Offshore Structure
Authors: Mintu Shafiul , Molyneux David 
Published: October 2021

Abstract
Ice floes in the marginal ice zone (MIZ) are exposed to wind, wave, and current forces which greatly influence the dynamics of the ice floes. ISO 19906 recommends considering combined wave and ice actions while designing offshore structures for arctic and cold regions. Few studies have focused on ice-structure interactions in waves. There are not many tools available to estimate these combined loads on structures. A numerical tool “SAMICE” has been developed to simulate the hydrodynamics of wave-ice interactions, but there exists a lack of data for a realistic MIZ under wave actions for validation studies of the numerical code.
To address this gap and to investigate the hydrodynamics of ice floes under waves, a set of experiments was conducted at the wave tank of Ocean Engineering Research Center (OERC) of Memorial University of Newfoundland. A six-component dynamometer was used to measure the loads on a model scale aluminum cylindrical gravity-based offshore structure. Loads were measured for five regular waves of various steepness in combination with three current speeds. Two ice concentrations with various floe sizes of random shapes were prepared from polypropylene sheets to represent the MIZ. Most of the tests were repeated three times and a statistical approach was used to analyze the loads. The preliminary analysis shows that the average wave-ice loads may be determined by ISO guidelines, but the predictions of impulse loads from individual wave-driven ice floes are very uncertain.