bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intelligent Defect Recognition of Pipeline Welds Based on Deep Learning for Phased Array Ultrasonic Testing Images
Authors: Zhang Ruyun , Dong Shaohua , Zhang Laibin 
Published: November 2024

Abstract
Non-destructive testing is a crucial process to ensure the quality of pipeline welding. Phased Array Ultrasonic Testing (PAUT) provides real-time scanning and imaging, and compared to radiogaphic testing, PAUT is harmless to humans and the environment, with accurate defect localization and high sensitivity. However, due to its relatively short history of widespread adoption, there is a shortage of professionals and teams trained in PAUT compared to traditional testing techniques such as radiography. In this paper, we study the intelligent defect recognition technology for welds in pipelines using deep learning-based Phased Array Ultrasonic Testing images. We establish a database of PAUT images for pipeline welds, including various types of defect detection images. Subsequently, we perform image peprocessing, to enhance features andreduce noise, thereby improving image quality. Multiple algorithms are employed for defect edge extraction to accurately identify weld defects. Finally, by analyzing the principles and issues of target detection, we improve existing models and frameworks and propose a novel deep learning-based framework for defect classification and localization in PAUT images of pipeline welds. Experimental results demonstrate that the proposed approach achieves high accuracy and localization precision in defect recognition of PAUT images for pipeline welds, providing effective technical support for automated evaluation of weld defects in pipeline systems.
Proposal of a New Flaw-to-Surface Proximity Rule for the Re-Characterization of a Subsurface Flaw Into a Surface Flaw
Authors: Lacroix Valéry , Dulieu Pierre , Hasegawa Kunio 
Published: November 2024

Abstract
When a subsurface flaw is detected close to the free surface of a pressure retaining component, it must be assessed whether the subsurface flaw shall be transformed into a surface flaw in accordance with flaw-to-surface proximity rules. Those re-characterization rules assume implicitly that if the interaction between the subsurface flaw and the free surface is too high, the remaining ligament is susceptible to break leading to this re-characterization of the subsurface flaw into a surface flaw. This re-characterization process from subsurface to surface flaw is adopted in all Fitness for Service (FFS) Codes. In the Section XI of ASME Boiler & Pressure Vessel Code, the limit value for this proximity rule depends on ratio be-tween the subsurface flaw to the free surface distance (i.e., the remaining ligament) and on the flaw depth. This limit value does not depend on the flaw aspect ratio.
This paper firstly demonstrates that, for a given flaw depth, the interaction between the subsurface flaw and the free surface of the component depends highly on the flaw aspect ratio. Therefore, the current flaw-to-surface proximity rule should account for this parameter as well. Then, the paper proposes an interaction limit criterion and presents a new limit value for the flaw-to-surface proximity factor, depending on the flaw depth, the remaining ligament and the flaw aspect ratio as well.
Revision of Long-Term Creep Strength of Base Metal of ASME Grade 91 Type Steel
Authors: Kimura Kazuhiro , Yaguchi Masatsugu 
Published: November 2024

Abstract
In a preliminary study on the creep rupture life scatter estimation of base metals of ASME Grade 91 type steel under actual service conditions performed by one of the authors, it was found that the creep rupture life curves and allowable stress of Grade 91 type steel pipes which were determined in Japan in 2015 may not be appropriate. Therefore, those were re-evaluated in this work by the Assessment Committee on Creep Data of High Chromium Steels, which consists of the Federation of Electric Power Companies of Japan, material producers, power plant manufacturers, and research institutes in Japan, which had evaluated the material in 2015. Creep rupture data were again provided for the re-evaluation by each organization of the committee, and creep rupture strength was assessed using the latest dataset of Grade 91 type steel by the region splitting analysis method in the same manner as in the previous study. It was suggested that the assessment should be performed at once simultaneously regardless of the product form such as pipes, plates, and tubes. As a result, the creep rupture life curves and allowable stresses of steel pipes were revised to the lower strength side than those in 2015. Furthermore, on the basis of the data and knowledge regarding the effect of chemical composition on the creep life of Grade 91 type steel, revisions to Japanese material codes regarding the chemical composition of Grade 91 type steel were proposed to prevent the production of low-strength Grade 91 type steel.
Effect of Temperature on Fretting Wear and Corrosion of 316L Stainless Steel In the Liquid Lead-Bismuth Eutectic (LBE)
Authors: Chen Hui , Zhang Shengzan , Tan Wei , Zhu Guorui 
Published: November 2024

Abstract
The change of temperature in liquid lead-bismuth eutectic(LBE) can lead to the formation of oxide film with different properties on the surface of structural steel. In the lead-cooled fast reactor, the heat transfer tubes are the important place for heat exchange in the steam generator. Affected by flow-induced vibration, the heat transfer tubes and the supports occur relative movement, resulting in fretting wear. The dense oxide film can protect the heat transfer tubes. Therefore, according to the temperature in operating conditions, this paper focuses on the influence of different temperatures on the fretting wear and corrosion of 316L austenitic stainless steel in LBE. The temperature ranges from 250°C to 600°C. With the increase of temperature, the friction coefficient decreases first and then increases, and the wear depth keeps increasing. When the temperature is 350°C–450°C, the wear depth increases slowly. Many small exfoliation layers and oxidized abrasive debris appeared on the wear scar surface. Meanwhile, no obvious dissolution corrosion occurred. When the temperature is 600°C, the wea depth increases rapidly to 9.63μm. Large exfoliation appeared on the wear scar surface. The NiO content on the wear scar surface decreases sharply to 2.36%, which indicates that the dissolution corrosion occurred severely, and the corrosion resistance of austenitic stainless steel decreased. 350°C–450°C is a temperature range, which is conducive to reducing the damage of fretting corrosion. The experimental results of this paper can provide reference data for the development of nuclear structural steel for lead-cooled fast reactors.
Tilting Manhole Cover: A Nonlinear Spring-Mass System
Authors: van de Meulenhof Niels F. , Tijsseling Arris S. , Vasconcelos Jose G. , Hou Qingzhi , Bozkuş Zafer 
Published: November 2024

Abstract
Manhole covers are potential “dancers”. They may leave their resting state and start “dancing”. They may hover, move up and down, tilt, rotate, bounce, make noise, flip over, or even fly up into the air. In general, their motion looks chaotic, probably due to the nonlinear dynamics governing the system.
The authors have previously derived basic models of dancing manhole covers covering the translational vertical motion of free covers and the rotational motion of hinged covers. In the current contribution the basic model is extended with tilting (without hinge) and bouncing behavior. Some fundamental problems and assumptions are discussed. Preliminary numerical results are shown together with 3D visualizations.
Scientific curiosity into a mysterious phenomenon has been the motivation for this study. The obtained equations governing the manhole cover’s motion may serve as boundary conditions in hydraulic-pneumatic models of sewer-manhole systems (think of geysering and ventilation).
Commissioning and Scalability of a High-Pressure Multi-Zone Autoclave for Polymer Synthesis
Authors: Schreiner Nicola , Weigel Christoph , Kirsch Julian , Gockel Lena , Busch Markus 
Published: November 2024

Abstract
On industrial scale, low-density polyethylene (LDPE) is produced at pressures and temperatures of up to 3500 bar and 300 °C. High-pressure tubular and autoclave reactors are used. Autoclave reactors usually show a high height-to-diameter ratio and are used as multi-zone autoclaves with additional feed points along the reactor axis. On laboratory scale most reactors used are stirred vessel with only one reaction zone. By means of residence time behavior and the possibility of temperature profiles, both types of reactors differ drastically. To bridge the gap between laboratory and industrial scale, this work shows the commissioning of a high-pressure multi-zone autoclave on lab-scale. An in-house designed stirrer is used, to divide the autoclave into three zones. During high-pressure polymerization experiments different zones of the autoclave are addressed. The response is given by temperature profiles. Subsequent, the effect on the molecular weight distribution is elaborated and discussed both experimentally and simulatively.
Influence of Resonant Acoustic Mode Shape on Source and Sink Patterns in the Wake of a Single Cylinder Based on Howe’s Energy Corollary
Authors: Shaaban Mahmoud , Rashed Mostafa R. , Mohany Atef 
Published: November 2024

Abstract
The interaction between the acoustic field and periodic flow structures in the wake of a cylinder can self-excite resonance and lead to undesirable noise and vibrations in heat exchangers. The underlying energy exchange mechanism responsible for the emergence of a resonant acoustic field depends on the coupling between flow and acoustic parameters in time and space. Previous investigations have demonstrated that a net positive acoustic energy rate over a complete coupled cycle is essential to sustain resonant conditions. However, existing models have primarily focused on the excitation of the fundamental acoustic mode, considering only one-way coupling, resulting in predominantly qualitative findings. This study utilizes Howe’s energy corollary to determine the amount of acoustic energy produced and absorbed by the flow moving downstream of a single cylinder in a rectangular duct. By considering full coupling, resonant mode shapes are self-excited, enabling the computation of the acoustic and flow fields, acoustic energy generation, and the phase delay between the acoustic field and the lift force. Results provide detailed insights into the coupling mechanism governing the first three transverse acoustic modes, which can be excited by the unsteady vorticity shedding from the cylinder within the relevant velocity range of interest.
Static Incremental Analysis With Modal Inertia Force Taking Into Account the Elastoplastic Nature to Estimate Elastoplastic Displacements of Structures
Authors: Taniguchi Tomoyo , Kaieda Takumi 
Published: November 2024

Abstract
Estimating the maximum elastoplastic response of structures during earthquakes is of interest to designers. To date, only the time history analysis can calculate elastoplastic responses of structures. However, such responses are considered lack generality, because dependence of responses on accelerograms cannot be eliminated, and thus they are not always adequate as the design quantities. Contrary, the design response spectrum is generated to provide a normative response which should be considered in design. Therefore, if we can calculate elastoplastic responses of structures based on the design response spectrum, structural healthiness during the severe earthquake can be verified. Such a motivation in mind, this paper develops a static incremental analysis to estimate elastoplastic displacements of structures. Its essence is that; 1) use modal properties according to the spring state and define the modal inertia forces with/without intercept of the restoring force from the absolute acceleration spectrum value, 2) define the intensity of base excitation after yielding so as to make the absolute acceleration in the global coordinates system continue and 3) calculate the maximum elastoplastic displacement of each floor by the modal combination rule. The displacement calculated form the proposed procedure is compared with that computed. Accuracy of the proposed procedure is clarified.
Performance Assessment of Additive Manufacturing Components for an Ex-Core Nuclear User : Valve Component – NUCOBAM Project
Authors: Misler Roxane , Hernandez Rebeca , Fernandez-Viña Antonio , Nardone Steve , Hary Benjamin , Bertelle Norman 
Published: November 2024

Abstract
In recent years, the nuclear industry has been exploring the potential of additive manufacturing (AM) to create components for nuclear power plants (NPP’s). Roadmaps have been developed within this sector, outlining the steps required to enable the use of AM components’ production. In this context, several projects have been initiated, including the European project NUCOBAM [1]. The overarching objectives of the NUCOBAM project (Nuclear Components based on Additive Manufacturing) is to tackle the technical challenges associated with manufacturing NPP’s components using AM [2].
One of the key elements within the NUCOBAM project involves the performance assessment of an ex-core component, specifically a valve. The AM process and alloy within the project’s scope are Laser Powder Bed Fusion (L-PBF) and the austenitic stainless steel grade 316L. This assessment will be incorporated into a methodology for qualifying components produced trough AM that adhere to nuclear codes and standards. This paper will offer a detailed presentation of the study related to additive manufacturing valve body and the qualification methods for this component, along with the procedures developed within the NUCOBAM project.
Review of Secondary Stress Treatment in the R6 Fracture Assessment Procedure
Authors: James Peter 
Published: November 2024

Abstract
This paper is looking to review ongoing developments related to the treatment of secondary stresses in low temperature fracture such that best practice and pertinent information are identified.
In recent years there has been considerable activity on work associated with understanding the impact of secondary stresses on fracture. Here, secondary stresses are defined as displacement-controlled stresses such as thermal and weld residual stresses that do not contribute to plastic collapse. The consideration of such secondary stresses is crucial to the ongoing justification of high integrity components. The range of work internationally that has focussed on the treatment of secondary stresses includes work performed as part of the R6 development programme, work within other UK national programmes into fracture and work published internationally in the open literature. Given the wide range of activities and potential developments elsewhere, it is considered timely to provide a review of the recent work to understand the areas of progress, relative strengths and weaknesses, potential gaps in understanding, and how this may lead to developments in the associated guidance (such as R6 and BS7910).
Flow-Induced Pulsation in a Header Configuration
Authors: Belfroid Stefan P. C. , Driessen Ronald J. A. , Gonzalez-Diez Nestor , van De Krol Bart 
Published: November 2024

Abstract
Double Tjoint configuration can generate high pressure pulsation amplitudes due to the interaction between vortex shedding and the acoustic resonance. Specific geometries are more susceptible due to the orientation between the acoustic field and the flow field. One geometry often encountered in the field is a header configuration. The arche-type of this is a header with an inlet and outlet (of equal diameter to the header diameter) at ¼ and ¾ of the header. The goal of this paper was to evaluate the sensitivity of the inlet diameter, the inlet location and the outlet location on the pulsation amplitude. A 150 m, 3m header was used in conjunction with a 75mm outlet and an inlet diameter of 25, 50 or 75mm. The inlet location could be varied between 5 locations, the outlet in 3 locations. Only in a limited number of configurations, a flow dependent frequency was measured. The source does not correspond to the sources found in literature for the arche-type. No consistent Strouhal number could be defined. The inlet did act as broadband source for the excitation of the main resonance modes. Smaller diameter inlets lead to a high number of modes excited with overall a high amplitude whereas a larger diameter leads to an overall lower amplitude with excitation of only lower modes.
Towards a Data-Driven Evolutionary Model of the Cyclic Behaviour of Austenitic Steels
Authors: Dorward Hugh , Knowles David , Mostafavi Mahmoud , Peel Matthew 
Published: November 2024

Abstract
Understanding the cyclic behaviour of austenitic stainless steels is important in assessing the integrity of pipework in a wide range of applications including in the nuclear industry. Design and assessment codes such as R5 address the cyclic evolution through phenomenological approaches which can also be informed by models such as Armstrong-Frederick, Ohno-Wang and Chaboche-Lemaitre. They aim to predict the evolution of combined isotropic and kinematic hardening under cyclic loading. More recently, advances have been made in the development of both phenomenological and physically based crystal plasticity models in modelling the cyclic behaviour of steels, however the application of these is limited by their computational expense.
In this study, the application of data-driven approaches for modelling the cyclic evolutionary behaviour is investigated. A synthetic cyclic dataset is produced through crystal plasticity finite element simulations to represent experimental cyclic data. A functional principal component analysis technique is proposed as a reduced order representation of the cyclic data to act as a data-driven parameterisation of the hysteresis curve. This method is shown to be able to accurately recreate the hysteresis loops with only a small number of scalar parameters.
Hydrogen Permeation Behavior of the Liner of Type IV Hydrogen Storage Cylinders Under Different Pressures
Authors: Qi Zhipeng , Shi Hao , Hua Zhengli , Yang Miaomiao , Peng Wenzhu 
Published: November 2024

Abstract
Type IV hydrogen storage cylinders are increasingly recognized as a prime solution for hydrogen storage in hydrogen fuel cell vehicles (HFCVs). Compared with other cylinders, this type of hydrogen storage cylinder is comprised of a polymer inner liner wrapped with carbon fiber composite material, offering advantages such as light weight, low cost, and fatigue resistance. Nonetheless, the polymer liner, typically fabricated from high-density polyethylene (HDPE) or polyamide (PA), exhibits notable hydrogen permeability, posing an increased risk of hydrogen permeation leakage. This constitutes a primary factor influencing the safety of its operational application in hydrogen storage contexts. In this paper, experiments on hydrogen permeation were executed under varied pressure conditions on two representative liner materials (HDPE and PA6) of Type IV hydrogen storage cylinders, aiming to scrutinize the relationship between hydrogen permeation performance of different liner materials and pressure, and to encapsulate the differences and consistencies between materials. Based on the test results, a finite element simulation was conducted on the hydrogen permeation behavior of the cylinder liner to probe into the effects of various liner high-pressure side pressures and liner thicknesses on the hydrogen permeation behavior, culminating in the formulation of the hydrogen permeation law of Type IV hydrogen storage cylinders. The outcomes of this study and the elucidated hydrogen permeation laws provide a fundamental reference for further research and design endeavors aimed at enhancing subsequent Type IV cylinder liners.
Prediction of Tensile Behaviour of Electron Beam Welded SS316L Using Crystal Plasticity Framework
Authors: Ashraf Farhan , Demir Eralp , Mokhtarishirazabad Mehdi , Mostafavi Mahmoud , Knowles David 
Published: November 2024

Abstract
Electron beam welding (EBW) is particularly attractive to the nuclear sector for joining future components due to its characteristic features, efficiency, and high productivity. In terms of its characteristics feature, EBW creates a narrow heat-affected zone and uniform energy density that minimize distortion and residual stresses in the weldment. Moreover, EBW can join thick components with uniform chemistry, however, it creates significant microstructural heterogeneities and different texture inducing directional properties in the weldment. The weld microstructure consisted of large columnar grains relative to the equiaxed grains of varying sizes in the surrounding parent material.
This work aims to study the effect of microstructure heterogeneities on the mechanical response of weldment using a crystal plasticity framework. The grain size and texture dependence of local deformation have been a grand challenge to model the mechanical response of metals. Here, we implemented a finite element crystal plasticity framework named “University of BRIstol cryStal plasTicity sOLver” (BRISTOL) that considers the effect of heterogeneous microstructure to predict the mechanical properties of the weldment in different loading directions. The comparison of model results with experiments shows that the proposed length-scale dependent model predicts accurate stress-strain response of the weldment in the longitudinal and transverse directions.
The Mechanical Behavior of Corrosion Resistant Alloys at Elevated Temperature With Internal Hydrogen
Authors: Ronevich Joseph , San Marchi Chris , Narasimhachary Santosh , Palmert Frans , Sheng Shilun , Wanjura Stefan 
Published: November 2024

Abstract
Structural materials used in combustion or power generation systems need to have both environmental and temperature resistance to ensure long-term performance. As the energy sector transitions to hydrogen, there is a need to ensure compatibility of highly-alloyed austenitic steels and nickel-based alloys with hydrogen over a range of temperatures. Hydrogen embrittlement of these alloy systems is often considered most detrimental near ambient temperatures and low temperatures, although there is some evidence in the literature that hydrogen can affect creep behavior at elevated temperature. In the intermediate temperature range (e.g., 100–400°C), it is uncertain whether hydrogen degradation of mechanical properties will be of concern. In this study, three alloys (304L, IN625, Hastelloy X) commonly used in power generation systems were thermally precharged with hydrogen and subsequently tensile tested to failure in air at temperatures ranging from 20°C to 200°C. At 20°C, the hydrogen-precharged condition for all materials exhibited loss in ductility with relative reduction of area ranging between 32% and 57%. The three alloys exhibited different trends with temperature but, in general, the relative reduction of area improved with increasing temperature tending towards noncharged behavior. Tests were performed at a nominal strain rate of 2 × 10−3 s−1 in order to minimize loss of hydrogen during elevated temperature testing. Hydrogen contents from the grip sections were measured both before and after testing and remained within 10% of starting content for 100°C tests and within 8–23% for 200°C tests.