bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vibration Propagation Analysis of Periodic Pipeline With Crack Defects
Authors: Wang Donghui , Zeng Qingna , Zang Fenggang , Zhang Yixiong 
Published: October 2021

Abstract
In this paper, the vibration propagation characteristic is investigated for periodic composite pipeline with crack damage. A novel modified transfer matrix method (TMM) is developed to investigate transverse Band Gap structures (BGs) considering fluid structure interaction, and validated by frequency response function (FRF) for finite period. Field transfer matrix is developed for straight pipeline conveying fluid, and point transfer matrix is derived for circumferential cracks damage based on spring hinge model, which could estimate the equivalent rotational stiffness by local flexibility coefficient method. It’s demonstrated that the existence of small crack damage has negligible effect on BGs, while severe crack damage has significant influence on vibration propagation even it only exists in a single cell. Meanwhile, the difference of FRF between cracked and perfect pipeline provides new idea in diagnosing the crack status. The influence of crack damage on BGs is mainly attributed to the equivalent rotational stiffness. Location of crack damage could affect the stiffness ratio of composite pipeline, and result in the change of original BGs. This study enriches the theoretical TMM for pipeline systems vibration with crack damage, and provides some reference for the stability design of periodic pipeline structures.
General Metal to Metal Static Seals Leak Tightness Overview - R&D Processes, FEA and Tests and Further Code Implementation
Authors: Lutkiewicz Przemyslaw , Robertson David , Lee Sam (Kwok Lun) 
Published: October 2021

Abstract
Latest development in oil and gas industry is focused on higher pressure and temperature. In addition, standard oil and gas components are more frequent adapted to the other applications like aerospace, food processing, renewable energy. For those conditions, tightness is even more critical than before. In the existing codes the requirements for different tightness classes can be find as well as detailed fugitive emission test descriptions. However, the complete design methodology for HPHT seal solution is still missing. There is no engineering procedure/methodology in the code which will link the design concept, R&D process to the prototype and real tests results. The method which will predict tightness for each size and each configuration/condition is not there. Therefore, there is an urgent need to understand the leakage phenomena and describe it by simplified and safe engineering method. Method, which will connect the design concept with real behavior and be in agreement (or conservative) with test results. By having such method, it will be possible to understand better the sealing mechanism in the existing solutions as well as designing new robust, simple, and cheap (optimized) solutions. There are some more or less accurate methods/rules which are already existing in the supplier companies. There is also more and more research about the continuum flow between two surfaces in contact. Based on those sources in this paper we will present the concept for metal to metal sealing solution designing methodology which can be implemented for future revision of the designing codes. The method which can be used simply and effectively and help to understand the current designs and further R&Ds. Presented here design concept, will be described based on example. The example will go through the process from design concept to the real component tightness test.
Use of Synthetic Flaws to Assess Pipeline Seam Weld Inspection Performance
Authors: Krynicki Joseph W. , Peng Lujian , Gonzalez Gustavo , Thirumalai Neeraj 
Published: October 2021

Abstract
Pipeline seam welds are often inspected using ultrasonic In-Line Inspection (ILI) technologies. The measurement performance specification of an ultrasonic ILI tool is based on simple, planar, machined notches which are very reproducible, but are not representative of the complex flaw morphologies that occur naturally in seams such as hook cracks and tilted lack of fusion flaws. In order to assess ILI performance on naturally occurring flaws, “in-the-ditch” Nondestructive Testing (ITD NDT) is performed to validate a subset of the population of ILI reported features.
Due to the limited number, type, and dimensional (height and length) uncertainty of these flaws, the field validation approach has limitations in terms of efficiency and accuracy in determining ILI detection capabilities and sizing performance.
Recently, specialized synthetic flaw fabrication technology has been developed and provides complex, natural crack-like morphologies with reliable and reproducible size dimensions. Effective validation spools with flaws (of representative geometries) can be achieved through engineered designs that consider the number, size and shape of manufactured flaws. This enables owners to quickly and reliably assess the performance of both ILI tools and ITD NDT operators.
Assessing performance with the synthetic flaw approach provides results that are more comprehensive and cost-effective compared to the typical field validation approach alone. This is because the flaw population is designed rather than randomly selected from excavation data.
This paper addresses the design, use and field experience with validation spools. This paper will present the performance of ILI tools and UT examiners based on synthetic flaw qualification exams, and how this supports related ILI and operator validation work.
ASME Section III Standards Committee Fatigue Action Plan
Authors: McKillop Suzanne , Donavin Paul , Keating Robert 
Published: October 2021

Abstract
The ASME Code, Section III, provides rules for the evaluation of cyclic loading that include evaluations of fatigue. These rules were first developed in the 1960s along with the original development of Section III. Since then, technology and analytical advancements have improved our understanding of the fatigue phenomenon. As an example, the developments in environmentally assisted fatigue (EAF) have become a major consideration in the low-cycle fatigue for light water reactors and plant life extension.
Fatigue usage has an outsized impact on the overall cost and complexity of nuclear plants, which goes beyond just the qualification of ASME components. For example, pipe break locations, pipe whip restraints, and inservice inspections are, in part, based on fatigue analysis results. Therefore, it is important that fatigue analyses provide the most realistic assessment of fatigue with appropriate conservatism.
The Section III Standards Committee has been working to keep the Code up to date with the latest research, analysis tools and fatigue data. In 2017, a Fatigue Steering Committee was formed to provide a venue for stakeholders to identify and coordinate development of updated fatigue design criteria, analysis methods, and their associated physical and thermo-mechanical properties for application to Section III of the ASME BPV Code. The stakeholders include many international organizations including the Japan Society of Mechanical Engineers. Many PVP papers have been used as the basis for the Fatigue Action Plan items. The Steering Committee completed its work in 2019 with the adoption of a Fatigue Action Plan, which provided a vision for advanced fatigue approaches. The Fatigue Action Plan recommended specific Code actions and activities to guide and coordinate the Code actions in the area of fatigue.
This paper outlines the overall Fatigue Action Plan and provides an update on the implementation progress. Section III has already accomplished several actions on the Fatigue Action Plan by publishing numerous Code Cases and Code revisions that have improved the analysis tools available to designers to address fatigue. This paper provides an overview and introduction to these Code Cases and other tools for designers.
The Fatigue Action Plan was largely based on addressing the need for the light water reactor fleet to address low cycle thermal fatigue. The Committee also recognizes that going forward the Fatigue Action Plan must address the needs of the growing advanced reactor community as well as other users of the Code. The paper discusses these needs and Section III plans to meet these future needs.
Verification of Accuracy of the Beam Model and Resistant Moment Generated by Base Uplifting of Flat-Bottom Cylindrical Shell Tanks
Authors: Yoshida Yuichi , Taniguchi Tomoyo , Nakashima Teruhiro 
Published: October 2021

Abstract
A purposes of this study are to confirm usefulness of the beam model (Malhotra and Veletsos, 1994) and to check if resistant moment generated by the base uplifting can be a function as a restoring mechanism against the overturning moment. First, this study shows an example of a result of force-displacement relationship calculated by the beam model (Malhotra and Veletsos, 1994), an estimation method of resistant moment and results of the FEM analysis. Next, this study tries to verify the beam model. The relationship between uplift width and uplift displacement calculated by the beam model is compared with the results of FEM analysis. Furthermore, the relationship between uplift force and uplift displacement calculated by the beam model is also compared with the results of the FEM analysis. These comparisons verify the accuracy of the beam model. After that, this study tries to verify resistant moment generated by the base uplifting by comparing with the overturning moment. These verifications imply usefulness of the beam model and existence of a restoration mechanism related to the movement of the content liquid.
Safety Assessment of Long Term Serviced Pressure Vessels: A Case Study of Typical Refining and Chemical Plants in China
Authors: Han Zhiyuan , Xie Guoshan , Jiang Haiyi , Li Xiaowei 
Published: October 2021

Abstract
The safety and risk of the long term serviced pressure vessels, especially which serviced more than 20 years, has become one of the most concerned issues in refining and chemical industry and government safety supervision in China. According to the Chinese pressure vessel safety specification TSG 21-2016 “Supervision Regulation on Safety Technology for Stationary Pressure Vessel”, if necessary, safety assessment should be performed for the pressure vessel which reaches the design service life or exceeds 20 years without a definite design life. However, the safety and risk conditions of most pressure vessels have little changes after long term serviced because their failure modes are time-independent. Thus the key problem is to identify the devices with the time-dependent failure modes and assess them based on the failure modes. This study provided a case study on 16 typical refining and chemical plants including 1870 pressure vessels serviced more than 20 years. The quantitative risk and damage mechanisms were calculated based on API 581, the time-dependent and time-independent failure modes were identified, and the typical pressure vessels were assessed based on API 579. Taking the high pressure hydrogenation plant as an example, this study gave the detailed assessment results and conclusions. The results and suggestions in this study are essential for the safety supervision and extending life of long term serviced pressure vessels in China.
Comparison of International Codes for a Fatigue Crack Growth Flaw Tolerance Sample Problem
Authors: Stevens Gary L. 
Published: October 2021

Abstract
As part of the development of American Society of Mechanical Engineers Code Case N-809 [1], a series of sample calculations were performed to gain experience in using the Code Case methods and to determine the impact on a typical application. Specifically, the application of N-809 in a fatigue crack growth analysis was evaluated for a large diameter austenitic pipe in a pressurized water reactor coolant system main loop using the current analytical evaluation procedures in Appendix C of Section XI of the ASME Code [2]. The same example problem was previously used to evaluate the reference fatigue crack growth curves during the development of N-809, as well as to compare N-809 methods to similar methods adopted by the Japan Society of Mechanical Engineers.
The previous example problem used to evaluate N-809 during its development was embellished and has been used to evaluate additional proposed ASME Code changes. For example, the Electric Power Research Institute investigated possible improvements to ASME Code, Section XI, Nonmandatory Appendix L [3], and the previous N-809 example problem formed the basis for flaw tolerance calculations to evaluate those proposed improvements [4]. In addition, the ASME Code Section XI, Working Group on Flaw Evaluation Reference Curves continues to evaluate additional research data and related improvements to N-809 and other fatigue crack growth rate methods.
As a part of these Code investigations, EPRI performed calculations for the Appendix L flaw tolerance sample problem using three international codes and standards to evaluate fatigue crack growth (da/dN) curves for PWR environments: (1) ASME Code Case N-809, (2) JSME Code methods [5], and (3) the French RSE-M method [6]. The results of these comparative calculations are presented and discussed in this paper.
Research on Modal Parameter Identification of Fuel Assembly Based on POD Method
Authors: Huang Xuan , Cai Fengchun , Liu Shuai , Feng Zhipeng , Liu Jian , Jiang Xiaozhou , Zhang Ke 
Published: October 2021

Abstract
In order to obtain accurate modal parameters of fuel assembly in the seismic test of fuel assembly, the finite element model of fuel assembly is taken as the research object, and the sine sweep signal is used as the excitation to act on the node of the model. On the basis of the transient dynamic analysis results, the transfer function of fuel assembly is obtained by using proper orthogonal decomposition (POD) method, and the modal parameters of the fuel assembly are identified by the least square iteration method, and the frequency, damping ratio and vibration mode of the fuel assembly in each mode are obtained. The transfer function obtained by this method and the transfer function calculated by single node response are used to identify the modal parameters respectively, and the results are compared with those of numerical calculation. The analysis results show that compared with single point response calculation, POD method can extract the key information of multiple nodes in time and space domain, and the calculation results of modal parameter identification are more accurate. This method can be used to identify the modal parameters of the subsequent fuel assembly test, and improve the utilization of the test data and the accuracy of the test results.
Stress Intensity Factor Predictions at Clad Interfaces
Authors: Brayshaw W. J. , James P. , Pellereau B. 
Published: October 2021

Abstract
Where a crack has grown such that it crosses a material interface, such as in a clad pressure vessel, there is an additional assessment requirement, above the surface and depth points to evaluate the material interface region. This is typically in terms of fatigue crack growth behaviour and crack extension by ductile tearing.
Generally, elastic stress intensity factor (KI) solutions, such as those in R6, only consider the surface and deepest point locations, and therefore do not provide a methodology to account for any interactions at material interfaces. Therefore, for a material interface, an assessment may look to describe the region by the maximum of the surface or deepest point values, or it may be argued to be represented by the value from either the surface or deepest point, depending on which is geometrically closer. However, this has the potential to lead to overly conservative interpretations in terms of KI and the elastic-plastic equivalent, KJ, at the material interfaces, depending on the fracture toughness and growth laws used.
The work presented here investigates the influence of the clad to plate interface on stress intensity factor under elastic (KI) and elastic-plastic (KJ) conditions for a number of defect geometries, loading conditions and material properties. The results presented in this paper seek to provide guidance on the suitability of KI and KJ for the surface and deepest points, extracted from models containing only plate material properties, to describe the behavior of a crack which crosses a material interface region in a clad pressure vessel wall.
Seismic Failure Modes and Loss of Containment in Industrial Equipment
Authors: Corritore Daniele , Paolacci Fabrizio 
Published: October 2021

Abstract
Major accidents in industrial plants and storage sites may be triggered by seismic events, due to the damage of process equipment resulting in a loss of containment. A quantitative seismic risk analysis is used to demonstrate the risks (individual, societal, economic, and environmental) caused by an activity involving dangerous substances, in the case of earthquakes. Starting from the seismic hazard curve of the site in which the plant is placed, the risk is evaluated through the seismic vulnerability assessment of the equipment, generally expressed in terms of fragility curves. The risk calculation necessarily involves the effects of the content release from a critical unit (e.g., tanks, columns, etc...), which can provoke important effects on the surrounding elements and community. For each critical unit, a set of relevant failure modes and damage states associated with the release of material should be defined. While for steel storage tanks, these failure modes and relationship damage state/loss of containment are available and used, the same cannot be said for the other typologies of industrial equipment as columns, horizontal vessels, compressors, furnaces, etc... This paper aims to provide a criterion to determine damage states and loss of containment resulting from the structural seismic damage for different categories of industrial equipment. This problem has been solved in a deterministic way by introducing a “damage state/loss of containment” correlation matrices. The definition of these correlation matrices for the most critical types of equipment makes it possible to fill a gap that existed in the seismic risk evaluation procedure of an industrial plant, also allowing to evaluate the mean annual frequency of exceeding a certain loss of containment from a critical unit due to the earthquakes.
Estimation of the Threshold Toughness in Acid Environments (KIEAC) By Using Circumferential Notched Tensile Specimens (CNT)
Authors: Arroyo B. , Álvarez J. A. , Gutiérrez-Solana F. , Cayón A. , Cicero S. , Andrea L. , Lacalle R. 
Published: October 2021

Abstract
Medium and high-strength steels working in harsh environments are susceptible of suffering of mechanical properties loss due to hydrogen presence. In order to avoid catastrophic failures, the estimation of the fracture toughness in environment is necessary, but sometimes it is not convenient the use of standard tests; an alternative to the aforementioned traditional fracture mechanics specimens are Circumferential Notched Tensile specimens (CNT), which consist of cylindrical tensile specimens that incorporate a circumferential notch. In this work, CNT specimens subjected to acid aggressive environments, generated by cathodic polarization, are used to estimate the fracture toughness in environment, KIEAC.
For this purpose, two methodologies, one proposed by Singh Raman et al. in the 2000’s and another by Cayón et al. in the 2010’s, are compared. Both formulations rely on similar classic fracture mechanics bases, differing mainly in the way to correct the effects of non-centering of the ligament, caused by asymmetries in the growth of annular cracks in CNT specimens. Both are finally validated to estimate KIEAC, showing good accuracy within the ±L15%.
Error Estimates in Extrapolation of Creep Rupture Data: Applied to an Austenitic Stainless Steel
Authors: Sandström Rolf , He Junjing 
Published: October 2021

Abstract
Precise time extrapolation of creep rupture data is a requirement for components operating at high temperatures. Although qualified models have been available for many years, there has been no way of quantifying the magnitude of the error in the results. To make an error analysis meaningful, requirements on the first and second derivatives are introduced, which are taken into account in the optimization of the model of the predicted creep rupture values. Formulae for the error are presented both for the case when the extrapolated values are interpolated from a master curve and when the values are extrapolated from the master curve.
The criteria have been applied with a time-temperature parameter for the austenitic creep resistant stainless steel Super304H (18Cr9Ni3CuNbN). The results showed a stable behavior with limited oscillating of the creep rupture curves. The prediction automatically fulfilled the post-assessments tests (PATs) proposed by the European Collaborative Creep Committee (ECCC), which are considered to be quite severe requirements.
Can the Four-Hour Installation Dwell Time Be Reduced?
Authors: Girão Carlos D. , Meira Igor , Veiga José Carlos 
Published: October 2021

Abstract
A correct bolted flanged joint tightening procedure includes retorquing to restore short-term creep relaxation and embedment losses; the ASME PCC-1-2019 Tightening Method recommends a minimum of 4 hours of dwell time before retightening the bolts.
It is known that in an industrial plant, maintenance costs come mostly from process downtime in addition to the labor and the tools necessary to perform the operation. Reducing the retorque waiting time would make installation quicker and avoid additional — and unnecessary — costs, returning the plant to revenue operation sooner.
This paper explores whether different gasket styles should have the same dwell time between the installation and retorque, and what would be the dwell time to minimize plant downtime without compromising the gasket performance.
The study was performed using a test rig based on a 4” class 300 ASME B16.5 flange equipped with eight strain-gauged bolts that correlates bolt elongation with applied stress. Four dwell times (15min, 1h, 4h and 24h) and different gasket styles and materials such as PTFE, CFG and metallic gaskets were tested. Additionally, two ASME PCC – 1 installation methods were compared and reported: Legacy Cross-Pattern Numbering System and Alternative Assembly Pattern #3. The former is the typical method for flanged joint tightening operations, while the latter offers a simpler, faster execution.
European Project ATLAS+: Large Scale Fracture Mechanics Tests on Ferritic Pipes
Authors: Dahl Anna , Vincent Willy 
Published: October 2021

Abstract
The 4-years European project ATLAS+ (Advanced Structural Integrity Assessment Tools for Safe long Term Operation) has been launched in June 2017. One of its objectives is to study the transferability of material ductile properties from small scale specimens to large scale components and validate some advanced tools for structural integrity assessment.
The study of properties transferability is based on a wide experimental program which includes a full set of fracture experiments conducted on conventional fracture specimens and large scale components (mainly pipes).
Three materials are considered in the program: a ferritic steel WB36 typical from secondary feed water line in German PWR reactors, an aged stainless steel austenitic weld representative of EPR design and a typical VVER austenitic dissimilar weld (DMW).
This paper describes preparation, realization, fractographic expertise and analysis of large scale tests performed on the ferritic steel WB 36 (15NiCuMoNb5). These large scale tests consisted of four point bending tests on piping’s conducted at room temperature. Two configurations of cracks (shape, size and location) were tested. With the first configuration (FP1), with a through wall crack, a large ductile tearing was obtained. For the second configuration (FP2), with an external semi-elliptical crack, cleavage was obtained after a limited ductile tearing.