bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Calculation Method of the Load Factor and Design for Bolted Gasketed Pipe Flange Connections Under Internal Pressure
Authors: Sawa Toshiyuki , Mabuchi Toshio , Sato Koji 
Published: November 2019

Abstract
The contact gasket stress reduces when the bolted gasketed pipe flange connections are subjected to internal pressure. In designing the bolted connections, it is needed to predict the reduced contact gasket stress, so, it is necessary to know the load factor. However, it is difficult to estimate the value of the load factor of the connections under internal pressure. In the previous paper (2018PVP), a more simpler calculation method was proposed. However, a more accuracy for obtaining the values of the load factor is desirable using the spring constants Ktg and Kcg. In the present paper, some calculation models for the spring constants are improved. Then, the values of the load factor for JIS 10K flange connections and ASME B16 flange connections with spiral wound gaskets are shown. The values of the load factor for the above connections are in a fairy good agreement with the FEM results. Using the obtained load factor, the residual contact gasket stress and an amount of gas leakage are predicted. The obtained calculated results of the load factor and the amount of the leakage are in a fairly good agreement with FEM results, and the measured results for 24” connection. As a result, the value of the load factor for the connections with larger nominal diameter is found to be negative and it decreases as the nominal flange diameter increases. In addition, a method how to determine the bolt preload for satisfying a give allowable leak rate is demonstrated.
Evaluation of Irradiation Embrittlement of the Chinese RPV Steels
Authors: Cao Yupeng , He Yinbiao , Wang Binxi , Huang Yifeng , Li Hui , Yu Yan , Hui Hu 
Published: November 2019

Abstract
Reactor pressure vessel (RPV) is considered to be irreplaceable, which is the most limiting factor for the lifetime of a nuclear power plant. This paper aims to introduce our project for the evaluation of the irradiation embrittlement for the Chinese RPV forging. The forging manufactured in China was irradiated in the high fluence engineering test reactor. Tensile tests, Charpy impact tests and fracture toughness tests in terms of master curve T0 were carried out for the material subjected to different irradiation fluences. Comparison of the mechanical properties of the irradiated materials and the materials without irradiation is made. The irradiation resistance of the materials in our project is also compared with the data for the irradiated RPV steels in the literatures.
Modeling Shock and Vibration on Used Nuclear Fuel During Normal Conditions of Transportation
Authors: Klymyshyn Nicholas , Ivanusa Pavlo , Kadooka Kevin , Spitz Casey 
Published: November 2019

Abstract
In 2017, the United States Department of Energy (DOE) collaborated with Spanish and Korean organizations to perform a multimodal transportation test to measure shock and vibration loads imparted to used nuclear fuel (UNF) assemblies. This test used real fuel assembly components containing surrogate fuel mass to approximate the response characteristics of real, irradiated used nuclear fuel. Pacific Northwest National Laboratory was part of the test team and used the data collected during this test to validate numerical models needed to predict the response of real used nuclear fuel in other transportation configurations. This paper summarizes the modeling work and identifies lessons learned related to the modeling and analysis methodology. The modeling includes railcar dynamics using the NUCARS software code and explicit dynamic finite element modeling of used nuclear fuel cladding in LS-DYNA. The NUCARS models were validated against railcar dynamics data collected during captive track testing at the Federal Railroad Administration’s Transportation Technology Center in Pueblo, CO. The LS-DYNA models of the fuel cladding were validated against strain gage data collected throughout the test campaign. One of the key results of this work was an assessment of fuel cladding fatigue, and the methods used to calculate fatigue are detailed in this paper. The validated models and analysis methodologies described in this paper will be applied to evaluate future UNF transportation systems.
Application of Machine Learning in Pipeline Integrity Reliability
Authors: Yin Eunice , Fernandes Phil , Woo Janine , Langer Doug , Hassanien Sherif 
Published: November 2019

Abstract
Probabilistic analysis is becoming increasingly adopted by pipeline integrity management practices in recent years. The practice employs reliability engineering methods to address pipeline integrity and safety concerns. At present, the industry is beginning to pair reliability methods with numerical methods to estimate probabilities of failure (PoF) for individual defects, or features, in a pipeline. The effort required for this can be intensive, since it must be repeated on hundreds of thousands of features, which need to be analyzed on a regular basis. This poses a challenge for pipeline reliability engineers, given limited human and computational resources.
In the meantime, machine learning applications in many industries have grown significantly due to advancements in algorithms and raw computing power. With massive amounts of raw data available from inline inspection (ILI) tools, and artificial data available through simulation techniques, pipeline integrity reliability becomes a promising field in which to apply machine learning technology to fast-track PoF estimation. Since a large population of reported features have low PoFs and pose low risk to integrity and safety, they can be safely screened out using fast machine learning models to free up engineers who can be dedicated to in-depth analysis of more critical features, which could have a much larger impact on pipeline operational safety.
In this paper, two machine learning models are proposed to address the pipeline integrity reliability challenges. The regression model was able to predict features with low PoFs with 99.99% confidence. The classification model was able to conservatively predict PoFs so that no high PoF feature was misclassified as being low PoF, while correctly filtering out 99.6% of the low PoF features. The proposed approach is presented and validated through pipeline integrity simulated case studies.
Fatigue Evaluation Method for Piping System Based on Total Input Energy and One-Cycle Momentary Input Energy
Authors: Sakai Michiya , Tamura Ichiro , Matsuura Shinichi , Shimazu Ryuya , Ono Yohei , Hagiwara Yutaka 
Published: November 2019

Abstract
In this study, the fatigue damage evaluation of seismic loadings was proposed and applied to an elbow of a three-dimensional simple piping system. The energy evaluation method was employed, focusing on energy balance of the total input energy and energy absorption of the piping system. Moreover, the concept of one-cycle momentary input energy was used for counting the loading cycle. Fatigue damage evaluation of the piping system was performed according to the maximum response of the elbow from the experimental results. The fatigue evaluation results were compared with the shaking test results of the piping system. Moreover, they were determined to be within the factor of 2 range, and were demonstrated to be applicable.
Effect of Welding Conditions on Sheets’ Interface Properties in Friction Stir Spot Welding of Copper
Authors: Mahgoub Ahmed , Merah Neçar , Bazoune Abdelaziz 
Published: November 2019

Abstract
Friction Stir Spot Welding (FSSW) is a solid-state joining technique widely applied to high conductive metals. In this paper, the effects of FSSW parameters, namely, rotational speed (N), plunging rate (V) and dwell time (DT) on the joint fracture mode and fractured surface morphology were investigated using scanning electron microscopy (SEM). The effect of the abovementioned welding parameters on the microhardness profile along the sheets’ interface was also investigated to gain insight into the strength of the joint and the width of the bonding ligament. Two conditions were considered for each parameter 1200 rpm and 900 rpm for N, 60 mm/min and 20 mm/min for V, 4 and 2 seconds for DT. The welding condition 1200 rpm rotational speed, 20 mm/min plunging rate and 2 seconds dwell time showed a wider bonding ligament, relatively higher elongation, higher tensile failure load, and greater microhardness on the sheets’ interface.
Dimple surface morphology (DSM) with regular dimples along the stir zone was also observed at the abovementioned set of process parameters.
Estimating Collapse Pressure of Centralizer Subs From Machine Learning Models
Authors: Chakraborty Ishita 
Published: November 2019

Abstract
Centralizer subs are run in conjunction with the casing strings in the oil/gas wells to ensure that the casing is centralized while it is installed down hole. Centralizer subs are fabricated of stronger material than the casing strings and designed such that it can sustain a higher collapse pressure than the attached tubing string. A typical centralizer sub is a tube with some complex geometrical features, so the collapse pressure of a centralizer sub can only be estimated by conducting a finite element analysis or subjecting it to a collapse pressure test. Both the options are time consuming and expensive.
In this work, a machine learning based regression model is used to derive a parametric equation for calculating the collapse pressure of a centralizer sub. The data needed to train and cross validate the regression model is obtained from finite element analysis (FEA).
This machine learning based equation provides a closer estimate of the collapse pressure of the centralizer subs to the results obtained from the FEA than the existing collapse prediction equations from API RP 1111. This machine learning based estimation of collapse pressure will help in correctly predicting the collapse rating of the centralizer sub without performing FEA or testing for each individual subs.
This approach of building machine learning models from data generated from FEA can be used for analysis of other equipment as well. With the availability of past data collected/generated through years, the recent advances in machine learning can be used to save time and resources.
Impact of BFJA Training on Bolted Flange Joint Assembly Reliability
Authors: Dupre Ross 
Published: November 2019

Abstract
A bolted flange joint assembly is a complex mechanical device, according to ASME PCC-1. A complex mechanical device’s reliability depends on many activities being performed prior and during the assembly of the bolted flange joint assembly (BFJA) being assembled. Some of these activities being; required torque calculations; gasket material selection, fastener selection, type of flange, fastener condition, lubrication, and maybe the most important activity being the assembly of the bolted flange joint. How does one ensure the correct methods and best practices being used during the assembly of the bolted flange joint?
Education. Educating not only the assemblers but also the engineers, supervisors, foreman, etc. By educating more than just the assemblers we can create a proper culture to ensure BFJA reliability. We can quantify increased BFJA reliability spurred from education by using surveys completed by the assemblers who have gone through the training.
Defining the How and When to Execute Single Stud Replacement (SSR) of Bolted Flanged Joints
Authors: Rodery Clay D. , Hamilton Scott , Ferguson Neil , Jung Gonghyun 
Published: November 2019

Abstract
Single Stud Replacement (SSR), or as currently known in ASME PCC-2 as “Hot Bolting” is the removal and replacement of studs on a bolted joint on a one at a time basis in a predetermined sequence. One of the key aspects in the successful execution of this activity is the determination of the appropriate maximum pressure governing the operation. The guidance currently provided in ASME PCC-2 is somewhat arbitrary and vague, and some clearer definition of a technical basis in this area would be valuable to industry in terms of both productivity and safety.
To provide additional clarity to this activity, a Task Group within the ASME Post Construction Subcommittee on Flanged Joint Assembly is redrafting the article detailing procedures for Single Stud Replacement. This paper discusses the work and focuses on the task of determining and documenting a technical basis for setting the limits (e.g., maximum pressure, effects of external moments, etc.) to safely execute a Single Stud Replacement operation.
Longitudinal Seam Welded Piping Assessment in Refinery Reformer Units
Authors: Dalal Mitul , Penso Jorge , Dewees Dave , Brown Robert 
Published: November 2019

Abstract
Creep is progressive deformation of material over an extended period when exposed to elevated temperature and stresses below the yield strength. Poor Creep ductility and cracking can be a problem above 900 °F (482°C) in the HAZ of low alloy (Cr-Mo) steel. High stress areas, including supports, hangers and fittings are more vulnerable to cracking. Creep cracking has occurred in longitudinal pipe welds with excessive peaking or welds with poor quality. Numerous incidents of cracking in low alloy (Cr-Mo) steel have been reported in the power industry and in refineries with major concern in longitudinal seam welds as well as highly stressed welds in reactors-heaters interconnecting piping. This paper presents the results of an assessment performed on reactors-heaters interconnecting piping in a catalytic reformer unit with a maximum operating temperature of about 950 °F (510 °C) at 250 psig (1.7 MPa) (&gt; 40 years in-service). Comprehensive inspection including visual, dye penetrant testing, thickness measurements and peaking measurements have been performed. Phased Array Ultrasonic Testing (PAUT) was utilized to detect crack-like defects and flaws. Detailed pipe stress analysis and finite element analyses (FEA) were also performed.
Proving Pipelines Safety Through Integration of Non-ILI to ILI Integrity Programs
Authors: Ibrahim Mahmoud , Hassanien Sherif , Lamborn Lyndon , Hubert Yvan 
Published: November 2019

Abstract
The integrity of transmission oil pipelines are often managed through in-line inspections (ILI) at regular intervals. For the last two decades, such ILI-based integrity programs along with excavations and field non-destructive testing (NDE) have proven their effectiveness in terms of reliability. In a few cases, some pipes contain; for example, a unique cracking mechanism exhibited by short, deep axial cracks located in the vicinity of girth welds. These attributes pose sizing difficulties for ultrasonic crack ILI tools. Accordingly, operators may lean on supplemental integrity activities to prove the safety of the pipelines such as; but not limited to, hydrostatic testing, laboratory testing of cut-outs, qualitative ranking of features, borehole leak detection analysis, Just-Missed-Flaw (JMF) or Just Surviving Flaw (JSF) analysis, discharge and/or point pressure restrictions, and/or a mix between all the previous techniques. Moreover, it is the operators’ responsibility to evaluate the risk associated with their integrity plans. Hence, it is important to be able to analyze the reliability of such integrity activities quantitatively. This paper presents an event-tree approach which can augment standard ILI or hydrostatic test results and probabilistic analysis with non-ILI integrity measures under one umbrella. In this approach, the likelihood of failure for both leak and rupture modes can be comprehensively estimated. The event tree approach is used herein as an inductive analytical diagram in which failure events are analyzed using Boolean logic to examine a chronological series of subsequent integrity actions and consequences. The proposed approach is also designed to capture subject matter experts’ opinion into the analysis as part of the integrity management program. The work discusses a real practical application along with verification and validation elements of the proposed integrated approach.
Role of Constraint in Specimen Geometries When Evaluating Fracture Toughness/Material Fracture Resistance for a Surface-Flawed Elbow
Authors: Kalyanam S. , Wilkowski G. , Brust F. W. , Hioe Y. , Punch E. 
Published: November 2019

Abstract
The fracture behavior of a circumferential surface crack in an elbow was evaluated using past data from the International Piping Integrity Research Group (IPIRG-2) Experiment 2-4. The elbow tested was nominal 16-inch diameter Schedule 100 TP304 material, which was solution-annealed after final fabrication. The elbow was loaded with an in-plane-closing bending moment and internal pressure of 15.51 MPa (2,250 psig) at 288 C (550 F). The surface crack was 180-degrees on the ID surface and centered on the extrados, but after fatigue precracking the depth was variable and the greatest was at about 45-degrees from the extrados. FE analysis of the IPIRG-2 elbow test was conducted with a state-of-the-art and precise 3D FE mesh (including variable surface crack depth, variable thickness, and initial elbow ovalization). The flaw depth for the single-edge notch tension (SENT) tests was selected to be equivalent to the deepest point in the elbow specimen crack front that provided the largest J-value in the elbow experiment, i.e., ao/W = 0.68. Comparison of the J-value for initiation (Ji) and crack-tip-opening displacement (CTODi) at crack initiation suggested that there was a slight difference in constraint between an identical depth SENT specimen (a/W = 0.68 with the same L-R orientation as the surface crack in the pipe) and an elbow with a circumferential surface crack (a/t = 0.68) [Ji was 0.368 MN/m, (2.1 ksi-inch) in the SENT tests, while it was 0.490 MN-m (2.8 ksi-inch) in the elbow test]. The more significant finding in this work was that the compact tension (C(T)) test Ji-value was much higher at 1.086 MN/m (6.2 ksi-inch) or ∼3 times higher. The elbow to SENT to C(T) specimen comparison illustrates very large differences in constraint between these geometries. From past work by several researchers it was determined that the constraint in C(T) specimens gives Ji-values that agree well with a circumferential through-wall crack in a straight pipe, but this difference with surface-cracked elbow or pipe is envisaged to be new information to the international research community. Additionally, from state-of-the-art FE analysis of the 180-degree surface-cracked elbow test it was found that the maximum J-value occurs at a position that was about 45-degree away from the extrados location. This trend showed that caution should be exercised when selecting the crack locations for elbow integrity evaluation, since for shorter flaw lengths it may be more critical to consider a crack that is closer to the 45-degrees from the extrados, which could be true for fracture as well as stress corrosion cracking (SCC) elbow evaluations.
Simulations of Fully-Flexible Fuel Bundle Response due to Turbulence Excitation
Authors: Elbanhawy Osama , Hassan Marwan , Mohany Atef 
Published: November 2019

Abstract
This work presents a numerical model for a fully-flexible CANDU fuel bundle to predict the vibration response due to turbulence excitation. The model includes 37 fuel elements and two endplates. The contact between system components such as fuel-to-fuel and fuel-to-pressure tube is modeled using the single point contact method (SPC). A range of flow velocities was examined, and the associated impact forces and work rates were calculated. In addition, the stresses on the endplates due to vibration of the fuel elements were predicted.
Extension of Weighted Stress Intensity Factor Rate (WKR) Method to Characterisation of Varying Temperature and Loading Rate in Plant Realistic Waveform Fatigue Crack Growth Calculations
Authors: Currie Chris , Mann Jonathan , Gill Peter , Leary Daniel , Wright Keith 
Published: November 2019

Abstract
The reference Fatigue Crack Growth (FCG) rate behaviour for austenitic stainless steel in a deaerated Pressurised Water Reactor (PWR) environment is provided in ASME Section XI Code Case N-809. This FCG law is dependent on load ratio and environmental factors in terms of a defined temperature and rise time.
Previous papers by Emslie et al (PVP2016-63497 and PVP2017-65645) demonstrate that environmental FCG rate enhancement is significantly better characterised by Stress Intensity Factor (K) rate than by rise time. It also demonstrates that K rate effects are increasingly important towards the top of the load cycle (ie. closer to the maximum K) and provides the Weighted Stress Intensity Factor Rate (WKR) method to account for both effects under isothermal loading conditions.
This paper extends the WKR method to include varying temperature during the loading waveform, so that both complex K and varying temperature waveform FCG rates can be predicted. A substantial body of validation test data of standard compact tension specimens under such loading is provided in support of the presented method. Further testing is proposed to enable validation suitable for future inclusion of the proposed method within Code Case N-809.
Nut-Factor Variation on Coated High-Strength Steel Fasteners After Cycling Torquing
Authors: Rosas Omar , Garcia Atahualpa Oscar , Hernandez Jose , Girault Carlos , Oldiges Donald 
Published: November 2019

Abstract
This study presents recent research results on the Nut-Factor of coatings applied to high-strength steel threaded fasteners mainly used in the Oil and Gas industry. PTFE coatings are commonly used to protect B7 grade material from corrosion within the industrial marketplace; however, most coatings applied to threaded fasteners do not offer a consistent tightening and they are affected by torquing during assembly. This results in an inconsistent Nut-Factor and accuracy of the provided nut-factor is not only inconsistent but also lower than most published values. The lack of consistency in the engagement produces variations in the load when torque is applied, the same torque will produce different loads depending on the surface conditions of the threads, which changes every time the fastener is re-used. Therefore, the aim of this study is to provide data on the nut-factor of coated threaded fasteners after assembly/disassembly cycles and the use of different lubricants. Torque cycles were applied to threaded fasteners with different coatings, Nickel-Cobalt electroplating, Zinc undercoat with PTFE topcoat and TSA with PTFE topcoat. The nut-factor was calculated before and after commercial lubricants were applied. Nickel-Cobalt electroplating showed an outstanding performance compared to the other tested coatings since it offered the highest nut-factor consistency. This study summarizes the optimal operational conditions for lubricants and materials and how these conditions affect the nut-factor and thread engagement.