bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wind Turbine Planetary Gear Fault Identification Using Statistical Condition Indicators and Machine Learning
Authors: Peeters Cédric , Verstraeten Timothy , Nowé Ann , Helsen Jan 
Published: November 2019

Abstract
This work describes an automated condition monitoring framework to process and analyze vibration data measured on wind turbine gearboxes. The current state-of-the-art in signal processing often leads to a large quantity in health indicators thanks to the multiple potential pre-processing steps. Such large quantities of indicators become unfeasible to inspect manually when the data volume and the number of monitored turbines increases. Therefore, this paper proposes a hybrid analysis approach that combines advanced signal processing methods with machine learning and anomaly detection. This approach is investigated on an experimental wind turbine gearbox vibration data set. It is found that the combination of physics-based statistical indicators with machine learning is capable of detecting planetary gear stage damage and significantly simplifying the data analysis and inspection in the process.
Investigation of the Effect of Block Size, Shape and Freeze Bond Strength on Flexural Failure of Freshwater Ice Rubble Using the Discrete Element Method
Authors: Afzali Soroosh , Taylor Rocky , Bailey Eleanor , Sarracino Robert , Boroojerdi Marjan T. 
Published: November 2019

Abstract
Understanding ice rubble strength and associated failure mechanics is important for a variety of engineering applications in marine ice environments, including the design and operation of coastal, offshore, subsea and floating structures. As part of the Mechanics of Ice Rubble project, recent experiments have been carried out to study the strength and failure behavior of ice rubble beams and the freeze bonds that form between individual ice blocks. These new results serve as an important guide for the development of improved numerical models. The discrete element method (DEM) is a direct modeling approach which has the potential to both describe and enhance understanding of the behavior of brittle granular materials, especially with regard to the evolution of damage towards failure. In this study we present results obtained from a newly developed model for the 3D DEM open-source code LIGGGHTS. The ice model contains normal and shear springs that operate between neighboring particles which are bonded or that overlap due to compressional stresses. Energy dissipation is accounted for by using a viscous damping model. Using this DEM model, medium-scale freshwater ice rubble punch tests have been simulated for ice rubble beams with nominal dimensions of 0.50m × 0.94m × 3.05m. Rubble specimens were generated by “raining” individual DEM ice pieces into a rectangular form and compacting the rubble mass to achieve the target porosity. Before the compacting pressure was removed, bonds between contacting blocks were introduced with parameter values chosen based on representative freeze bond experiments. The ice rubble beam was then deformed by pushing a platen vertically downward through the center of the beam until failure occurred. For the numerical simulations presented here, two types of block size and shapes have been considered: cuboid blocks generated based on the size distribution of the actual rubble, and rubble blocks generated by image processing of actual blocks of broken ice used in the comparison experiments. Results obtained for these two scenarios are compared with corresponding experimental test data. These results highlight that the DEM model is useful for estimating the flexural strength of the rubble, simulating the failure mechanism and for examining the extent to which the ice rubble beam failure is controlled by the strength of the freeze bonds. These results also provide valuable new insights regarding the importance of shape and size distribution of ice blocks on simulated ice rubble strength and failure behavior. Recommendations for future work are provided.
Design of Performance Monitoring System for Diesel Generators of Offshore Drilling Platform
Authors: Hu Lei , Yang Jianguo 
Published: November 2019

Abstract
Conditions of diesel generators on an offshore drilling platform are crucial for oil production, if diesel generators can not work, the efficiency of oil production will be reduced, even worse, it will be a crisis to the offshore drilling platform security. So it is important to reduce maintenance costs and prevent major failures of diesel generators by using some effective means, such as establishing effective monitoring methods and strategies, predicting diesel generators’ working status and managing their operation data, it also can improve convenience for Platform crews’ operation and maintenance. Some on-line or off-line monitoring methods for diesel generators are applied widely, however monitoring strategies and integration technologies for the platform are not yet available. An integration strategy of online and off-line monitoring was proposed by using the instantaneous speed method, CP method and thermal parameters method. A suitable performance monitoring system for diesel generators is composed of performance monitoring module, data management module and network communication module. The system was developed based on virtual instrument technology, by data acquisition, analysis, processing of different types of sensors and design of monitoring strategy and system interface, the status monitoring and prediction of diesel generators is realized. The method was tested on a laboratory diesel engine, the performance and function of the monitoring system were verified. Then the system is validated on a drilling platform, and results indicated that the functions of the developed system met the designed requirements and the performance was reliable.
Fatigue Assessment of Dented Rigid Risers
Authors: Santander Elvis J. O. , Pinheiro Bianca , Magluta Carlos , Roitman Ney 
Published: November 2019

Abstract
In the development of oil fields, submarine pipelines are used in various applications. These pipelines and risers are subject to accidents that may occur during operation, such as shocks between risers or shocks between a riser and an anchor, rock, or any equipment or heavy object, which may cause mechanical failure, such as dents. The objective of this work is to study of the effect of the introduction of plain dents on the structural integrity of rigid risers under fully reversed bending. A three dimensional finite element model was developed to estimate the stress concentration on dented risers under bending. Several numerical simulations were carried out to evaluate stress concentration factors (SCFs) for varying dimensions of dents and risers, in a parametric study. These SCFs can be used in the prediction of the remaining fatigue life of dented rigid risers.
Validation of External Moment Determination for the Shaft-Line of the S.A. Agulhas II
Authors: Nickerson Brendon M. , Bekker Anriëtte 
Published: November 2019

Abstract
Full-scale measurements of shaft torque have been performed on several voyages of a polar supply and research vessel, the SA Agulhas II. Previous work has looked at the determination of the externally induced ice moments on the propeller to shed light on the expected loading conditions in the harsh Antarctic environments. This has been done by making use of a lumped mass model, measurements taken on the shaft-line and an inverse prediction algorithm. Thus the externally applied loads are determined through the internal measurements on the shaft-line. The work presented here is in an effort to assess the validity of the lumped mass model parameters used in the external moment determination process. Two methods of validation have been performed. The first is through the comparison of the lumped mass model to operational modal analysis data of the shaft-line, obtained during dry-dock operations in 2017. The second validation method that is considered relies on data recorded on board the SA Agulhas II during its 2018–19 Annual Relief Voyage to Antarctica. The shaft-line measurement system has been expanded to include the measurement of torque at a second location, further down the shaft. These two measurement locations are each used to determine the external loads and their results are compared. It was found that the results of the validation show correlation, albeit with some error, and that the developed method is valid for use in determining externally induced ice moments. However, there is room for improvement of the current external moment determination method.
Solving 2-D Slamming Problems by the Higher-Order MPS Method With an Improved Pressure Gradient Model
Authors: Zha Ruosi , Peng Heather , Qiu Wei 
Published: November 2019

Abstract
A higher-order moving particle semi-implicit (MPS) method was developed to solve water entry problems. The Wendland kernel function was applied in the particle interaction model. Various models for pressure gradient were investigated. To overcome the inconsistency in the original MPS methods, a pressure gradient correction was implemented to guarantee the first-order consistency of gradient. The corrective matrix was modified by using the derivative of the kernel function. A particle shifting technique was also applied to improve the numerical stability. Validation studies were carried out for water entry of a rigid wedge with the tilting angles of 0°, 10° and 20°, and a rigid ship section. The solutions by the present method are generally in good agreement with experimental data and other published numerical results.
Computational Investigation of Oil Accumulation in a Subsea Deadleg
Authors: Caglar Egemen , Zeng Yi , Khodadadi J. M. 
Published: November 2019

Abstract
Both 2- and 3-dimensional computational studies of two-phase flow within a horizontal pipe with a vertical deadleg placed downstream of an oil/water supply source were considered as part of a model subsea petroleum production system. Two-phase continuity and momentum relations were solved using the open-source computational software OpenFOAM. The unsteady flow behavior of the two-phase dispersed mixture which consists of 90%–10% slurry of 32.8 API crude oil-water at the inlet port (Reynolds number of 2.1 × 105) was investigated. With the 2-D simulations, the effects of the average inlet velocity, diameter of the deadleg and length of the deadleg on the oil fraction within the deadleg and the stagnant zones were studied. Results of the 3-D unsteady simulations exhibited the complex vortical flow field and separation of the two phases that evolved within the deadleg leading to migration of separated oil to the top of the deadleg.
Numerical Study on the Effect of Stern Flap for Hydrodynamic Performance of Catamaran
Authors: Zhou Peng , Liu Liwei , Guo Lixiang , Wang Qing , Wang Xianzhou 
Published: November 2019

Abstract
This paper presents CFD simulation results of the stern flap effect with different lengths for hydrodynamic performance of catamaran moving in calm water, including resistance and sailing attitude. Inhouse viscous CFD (computational fluid dynamics) code HUST-Ship (Hydrodynamic Unsteady Simulation Technology for Ship) is used for the study. The catamaran with/without stern flap with different lengths were studied. The trim and sinkage of the catamaran were solved coupled with flow solver. Experimental studies in calm water were conducted to validate the numerical method. The comparison of hydrodynamic performance of catamaran with stern flaps of different lengths was made. The results show that the stern flap can reduce the sailing attitude and has influence for the resistance of catamaran at high-speed.
Study of the Vortex-Induced Vibration of the Marine Risers With the Buoyancy
Authors: Zhao Lin , Su Hang , Yin Yanju 
Published: November 2019

Abstract
Regarding the very large top tension of ocean deep water riser which is caused by the heavy self-weight, a innovated buoyancy system is designed. This system can effectively decrease the top tension and improve the performance of the riser movement. In order to study the upper and lower part of the floating system, a specialized model test is carried out, where the acceleration, amplitude, frequency and trajectory of the interested points along the risers are investigated. It has been observed that with the increase of the current speed, both the vibration acceleration and the vibration frequency are increasing but the bare riser amplitude is decreasing. At the speed of 0.2m/s, the resonance phenomenon is observed, but the same phenomenon is not observed for the middle floating riser subjecting to different flow velocities. At the speed of 0.4 m/s, the largest amplitude is captured. Due to the response differences of the floating riser at the up and down parts of the middle floating riser, when the amplitude is increasing, the vibration frequency is decreasing, both at cross flow (CF) direction and inline flow (IL) direction. Especially the vibration behavior of the interested points is most influenced by the buoyancy. Under different models, vibration at different flow velocities is presented along bare riser, the modal vibration effects of the floating riser will decrease In addition, according to the experiment condition, Orcaflex is applied to conduct the numerical simulation to get the vibration law of the corresponding feature points and compare it with the experimental results. The results indicate that the numerical analysis reasonably match with experimental results.
Analysis of Products Pipeline Accident Infiltration Process in Surface Soil Condition
Authors: Wang Xiao , Liang Yongtu , Liu Shengli , Wu Mengyu 
Published: November 2019

Abstract
The most common way of transportation for refined oil is long-distance pipeline. Pipeline accidents occur frequently due to corrosion, equipment failure, external forces destruction. Aiming at predicting the contaminated area in soil caused by products pipeline accidents, this experimental study was conducted to examine the relationship between the light non-aqueous phase liquids (LNAPL) accumulative infiltrate volume and the time of infiltration process in homogeneous and layered soils. The soil’s hydraulic parameters were obtained by basic experiments and RETC software. Compared with traditional infiltration mathematical model, Green-Ampt model is the most common mathematical model to calculate the infiltration process in the unsaturated soil. In this study, a modified Green-Ampt model was developed to describe water and diesel infiltration through a 100-cm-long and layered soil column. In the modified Green-Ampt model, an infiltration reduction ratio was introduced to describe the effect of the hydraulic conductivity of the layered position. To evaluate the proposed method in the effect of the layers position infiltration permeability, eight constant water head layered column infiltration experiment were conducted to record the different infiltration fluid and different constant water head infiltration process. Compared the experiment results with traditional mathematical traditional Green-Ampt model (average R2 = 0.976) and Hydrus-1D software (average R2 = 0.988) The modified Green-Ampt model had relatively higher precision in accumulative infiltrate volume (average R2 = 0.992) and the wetting front velocity in infiltration process (average R2 = 0.997). Thus, the modified mathematical model was applied an effective upscaling scheme in layered formations. The experimental result also demonstrated that soil layering affected the infiltration process. With the increase of soil depth and density, the infiltration speed of the layered soil column decreased. Additionally, the infiltrate speed of wetting front decreases slowly at the layered surface. The experiment’s fitting results showed that the modified mathematical model about infiltrate time and liquid contaminant accumulative infiltrate volume, wetting front infiltrate velocity can highly effective approach to simulate water and light non-aqueous phase liquids (LNAPL) infiltration process in layered soils.
Assessing Low-Constraint Fracture Toughness Test Methods Using Clamped SENT Specimens
Authors: Zhu Xian-Kui , McGaughy Tom 
Published: November 2019

Abstract
The low-constraint fracture toughness can be measured using a single edge-notched tension (SENT) specimen in the clamped-end conditions. The SENT specimen has been used in the oil and gas industry in the strain-based design and the crack assessment for transmission pipelines. Since 2006 when DNV published the first SENT test practice, many investigations have been done, and various SENT test methods were developed, including CANMET and ExxonMobil methods in terms of the J-integral and CTOD. The effort led to the first SENT test standard BS 8571 being published in 2014. However, the experimental evaluation methods remain in developing, and different methods may determine inconsistent results. For this reason, the present paper gives a brief review on SENT fracture testing and assesses the available test methods, including progresses on study of stress intensity factor, geometric eta factors, elastic compliance equation, and constraint m factor as well. The difference between J-converted CTOD and double clip gage measured CTOD is also discussed. On those bases, agreements and challenges in SENT testing are identified. The results provide a direction for further investigation to improve the current SENT test methods.
Recent Improvements in Toughness Prediction of Cast Duplex Stainless Steel Components
Authors: Le Delliou Patrick , Saillet Sébastien 
Published: November 2019

Abstract
Thermal ageing of cast duplex stainless steel components is a concern for long-term operation of EDF nuclear power plants. The thermal ageing embrittlement results from the microstructural evolution of the ferrite phase (spinodal decomposition), and can reduce the fracture toughness properties of the steel. In addition, it is necessary to consider manufacturing quality and the possible occurrence of casting defects such as shrinkage cavities. In a context of life extension, it is important to assess the safety margins to crack initiation and crack propagation instability. One major input of the assessment methodology is the toughness value of the thermally aged component. Recent work conducted at EDF R&D to improve the accuracy and the conservativeness of the toughness prediction has led to the development of new prediction formulae.
The toughness prediction relies on three steps:
• estimation of the Charpy impact test values at 20 and 320°C using the chemical composition of the steel and the aging conditions (temperature and duration),
• estimation of the J-R curve at 20 and 320°C - defined by a power law J = CΔan - thanks to correlations between n and C and the Charpy impact test values,
• estimation of the J-R curve at any temperature between 20 and 320°C thanks to interpolation formulae.
The paper presents the experimental data used to develop the formulae, the formulae themselves and some elements of validation.
Technical Basis and Strategy for Consolidation of ASME Boiler and Pressure Vessel Code, Section III, Subsection NC (Class 2) and Subsection ND (Class 3) Into a Single Subsection
Authors: Wen Jie , Keating Robert , Adams Timothy M. 
Published: November 2019

Abstract
ASME Boiler Pressure Vessel Code, Section III, Division 1, Subsection NC, Class 2 components, and Subsection ND, Class 3 components, have significant technical and administrative similarities. The ASME BPV III Standards Committee has a long-standing goal of combining these two subsections (NC and ND). Consolidating Subsections NC and ND will simplify, reduce repetitions and make the Code easier to use. Additionally, a combined Subsection NC/ND will simplify Code maintenance. To facilitate this consolidation, the Subgroup on Component Design, under the BPV III Standards Committee assigned a Task Group to develop a strategy to combine the two subsections into a single subsection while maintaining both Class 2 and Class 3 as separate classes of construction.
Both Subsections NC and ND of the Code have been completely reviewed, compared and the technical bases for the differences have been established. The conclusion of this review is that there are only a few major technical differences between the two code class rules; however, there are a significant number of editorial differences. Based on the review, the Task Group developed a strategy that completes the consolidation within two publishing cycles of Code edition. For the Code Edition 2019, two separate Subsections NC and ND books will be published to resolve editorial differences and otherwise align the two subsections. For the Code Edition 2021, a single merged subsection will be published. This paper provides the background for the proposed code change, discusses the detailed result of the NC/ND comparison, and provides the basis for the major technical differences. The paper will also update the status of the project and code actions needed to consolidate to a single subsection.
Fitness-for-Service Strategies for Impulsively Loaded Vessels
Authors: Duffey Thomas A. , Fehlmann Kevin R. 
Published: November 2019

Abstract
High-explosive containment vessels are most commonly designed for repeated use, implying predominately elastic material behavior. Each explosive test imparts an impulse to the vessel wall. The vessel subsequently vibrates as a result of the internal blast loading, with amplitude diminishing exponentially in time due to structural damping. Flaws present in the vessel could potentially grow by fatigue during these vibrations. Subsequent explosive tests result in new sequences of vibrations, providing further opportunity for existing flaws to grow by fatigue. The obvious question is, ‘How many explosive experiments can be performed before flaws potentially grow to unsafe limits?’ The evaluation of remaining life and fitness-forservice of explosive containment vessels draws upon three interrelated codes and standards: Section VIII, Division 3 of the ASME Boiler and Pressure Vessel Code; API-579/ASME FFS-1; and ASME Code Case 2564. The paper discusses their implementation in determining the remaining life of dynamically loaded vessels that have seen service and are potentially damaged. In this paper, results of a representative explosive containment vessel are presented using actual flaw data for both embedded weld flaws and fragment damage. Because of the potentially large number of flaws that can be detected by modern non-destructive inspection methods, simplifying procedures are also presented for conservatively eliminating from further consideration the vast majority of the flaws that possess considerable remaining life.
Investigation on the Protection of the End Cover of the Cylindrical Containment Vessel
Authors: Zhang Liucheng , Dong Qi , Yang Sha , Feng Jiahe , Hu Rongxi 
Published: November 2019

Abstract
The cover of a cylindrical explosion containment vessel would suffer an extremely intense impact because the shock wave and blast products would converge at the cover area. To reduce the impact of shock waves to the cover, cases with aluminum foam placed at the end of the vessel and in the interior of the cylindrical portion are studied by numerical simulation and experiment. The result shows that aluminum foam located at the end of the vessel can have a great effect on the protection of the cover because it can absorb the energy of the shock wave that has spread to the end of the vessel. Aluminum foam located in the interior of the cylindrical portion would have a negative effect on the protection of the cover because it would reduce the distance between the charge and the cylindrical portion, the effect of which is more significant than the effect of energy absorption. These results can contribute to the design of cylindrical explosion containment vessels.