bluuebunny/crossref_metadata_2025_split huggingface dataset:
Post Weld Heat Treatment and Fracture Toughness Evaluation of Electron Beam Welded SA508 Alloys
Authors: Cooper Adam J. , Wisbey Andrew , Kyffin William , Dutilleul Thomas , Nunn Mike , Punshon Chris , Smith Mike C. , Pickering Ed , Akrivos Vasileios , Carruthers Alex 
Published: November 2023

Abstract
Whilst Electron Beam Welding (EBW) has been in existence for several decades, it typically requires the welded component to be housed within a conventional vacuum chamber in order to minimize diffusion of the electron beam, thus limiting the maximum overall size of the component. Recent advances in EBW by TWI (UK) have led to the development of a local vacuum system, whereby a local vacuum is implemented around only the welded section rather than the whole component, thereby avoiding the component size limitations associated with more conventional systems. A direct comparison between the two EBW systems does not appear to have been published hitherto and thus forms one aspect of the work reported here.
For the EBW low alloy steel SA508 materials employed in this study, the post weld heat treatment (PWHT) regime has also been investigated, since there has been some concern over the appropriateness of employing conventional PWHTs typically used for traditional arc welds. Charpy impact testing was performed to assess the initial toughness of the welds, with the notch located on the weld centre-line, within the HAZ, and within the parent materials. For SA508 Gr.3, Charpy testing suggested that only the full austenitise and temper heat treatment gave weld centre-line properties similar to the parent material. However, for SA508 Gr. 4N, a modified single step PWHT restored a high level of toughness performance to the weld metal, in comparison with the parent.
Finally, fracture toughness testing on the SA508 Gr. 3 and SA508 Gr. 4N materials has been undertaken to determine the upper shelf fracture toughness (J1C) at 250°C, using multi-specimen compact tension (C(T)) test specimens. These data showed that there were little observable differences in the performance of welds produced by either the conventional high vacuum welding system, or the local vacuum system.
Cryogenic Aluminum to Stainless Steel Pipe Transition Joint Qualification
Authors: Ok Ali , Dally John A. , Tentarelli Stephen C. 
Published: November 2023

Abstract
Many cryogenic heat exchanger applications use aluminum pressure vessels that are connected to stainless steel piping typically either by dissimilar metal flange pairs or aluminum to stainless steel transition joints. Transition joints can provide a number of advantages over flanges. Transition joints can save space and weight over flanges, and provide a leak tight connection which can eliminate fugitive emissions. Aluminum to stainless steel transition joints have been built using different technologies, including:
1. Friction welding
2. Explosion welding
3. Nonwelded, diffusion-bonded (heat shrinkage/hot pressing assembly)
This paper focuses on explosion-welded transition joints, although some of the concepts discussed may also apply to other technologies. ASME Pressure Vessel and Piping codes do not provide specific design guidelines or qualification requirements for these joints. ASME Code Case 2493 provides qualification requirements for explosion welding of dissimilar metal plates, but not for the final transition joint design. This paper shall highlight an approach to addressing specific concerns regarding the qualification and production testing of explosion-welded plates and transition joints for cryogenic applications. It shall also cover aspects of the design, qualification, and rating of the cryogenic transition joints made from explosion-welded parent plates.
ASME B31.3 Section 304.7 Pressure Design of Other Components addresses the pressure design of unlisted components in 304.7.2, which provides four acceptable qualification methods. This paper will discuss two of those methods: proof testing and detailed stress analysis, i.e., Finite Element Analysis (FEA). A combination of these two methods can be used to ensure a safe and effective design.
Simplified Method for Adjusting the Shape and Characteristic Strength Parameters of the Weibull Strength Distribution of Graphite Materials
Authors: Saitta Michael , Beirnaert Gwennaël 
Published: November 2023

Abstract
The 2021 version of the ASME Boiler and Pressure Vessel Code Section III, Division 5, Paragraph HHA-3217 utilizes a 3-parameter Weibull distribution to characterize the strength of graphite materials. Subparagraph (g)(2) thereof requires that the designer modify the threshold parameter (S0). However, no guidance is provided to update the other parameters of the Weibull distribution following an update of S0 (i.e., Sc, the characteristic strength parameter, and m, the Weibull modulus or also referred to as the shape parameter). This paper illustrates why failing to update the other parameters results in an unrealistic and overly conservative distribution.
This paper provides a simple method to update the shape and characteristic strength parameters of the Weibull distribution. This method relies on a straightforward, algebraic formulation that is easy to implement and does not require access to the underlying experimental datasets. The performance of the method is evaluated and shown to compare favorably with maximum likelihood estimate (MLE) optimization using both simulated and experimental data. Differences between methods tend to be on the order of a few percent and are negligible for small changes to S0. Moreover, any deviations are further shown to be conservative for the purposes of stress analysis of graphite.
Challenges in KIH Testing Using WOL Samples for Pipeline Applications
Authors: Cravero Sebastian , Cristea Mihaela E. , Deul Marije L. , Walters Carey L. , Valdez Martín E. , Darcis Philippe 
Published: November 2023

Abstract
Gaseous Hydrogen can have detrimental effects on the mechanical performance of carbon steels, and those effects need to be taken into account for the proper design of pipelines for H2 transportation systems. ASTM E1681 is the standard test method used to evaluate fracture toughness in an H2 environment and presents the possibility of testing under constant loading or under constant displacement conditions. Given the comparative simplicity of testing self-loaded specimens in constant displacement, this type of test has become a “standard” for the industry. However, satisfying the different validity checks required by the testing standard presents several challenges that seems to be very difficult to solve. The present paper explores the limits in terms of dimensional requirements and stress intensity factor solutions using finite element simulations and experimental testing.
Sequentially-Coupled Hydrodynamic and Structural Analysis of Radiographic Windows in Blast Confinement Vessels for Proton Radiography of Physics Experiments
Authors: Fister Matthew , Spencer-Coker Christian , Fehlmann Kevin , Spernjak Dusan 
Published: November 2023

Abstract
Characterization of shock-driven materials via radiography is critical to the success of Los Alamos National Laboratory’s (LANL) mission. Radiographic experiments with both hazardous material and high explosives (HE) require a two-part pressure vessel containment system (PVCS) composed of an inner pressure confinement vessel (IPCV) and an outer pressure containment vessel (OPCV). A new PVCS developed for LANL’s Proton Radiography facility (pRad) will enable a suite of experiments with up to 1.06 ounces (30 grams) TNT-equivalent HE. The critical component of the IPCV is the beryllium radiographic window, which must withstand the blast pressures from the HE while minimizing radiographic blur. Because the amount of HE used in the suite of experiments will vary, the IPCV is designed to be modular, such that for each experiment a new radiographic window may be optimized and installed into the IPCV. Each radiographic window design must undergo an HE over-pressure test (OPT) per ASME specifications for impulsively-loaded pressure vessels. To optimize each window’s structural performance and radiographic blur, and to establish confidence that the window will survive the OPT, a sequentially-coupled hydrodynamic and structural analysis workflow has been automated, facilitating design-by-analysis starting at initial concept development and extending through pre-test predictions for qualification tests of a component under extreme environments.
Accuracy of the Time History Analysis of 2DOF Subjected to Base Excitations Based on the Superposition of the Elasto-Plastic Response of Each Mode
Authors: Taniguchi Tomoyo , Ueno Seiya , Shoji Yasumasa , Kimura Yukinobu 
Published: November 2023

Abstract
This paper develops the time history analysis of the elasto-plastic response of the 2DOF, consisting of two masses and springs that exhibit bilinear hysteresis, being subjected to a base excitation, based on superposition of the time history of elasto-plastic response of each mode. The essence of the proposed analysis is that the response of the 2DOF during the yielding of any springs consists of the mode frequencies, shapes and dampings that are readily specified by the eigenvalue problem employing the mass and the secondary stiffness of the spring yielded. First, the equations governing the response of each mode according to the state of spring and all quantities needed for them are described in detail. Next, a displacement time history of each mode is numerically and simultaneously analyzed, because the response of each mode is superposed at every time step to verify the elastic limit or turn-around points of each spring that are only verifiable in the global coordinates system. Once the response exceeds the elastic limit of each spring or the turn-around points, the equations of motion of each mode are switched to those of the next state of spring. Finally, the accuracy of the proposed method is thoroughly discussed. Moreover, the force-displacement diagram of each mode is presented. The applicability of the SRSS method is also examined.
Fracture Load Predictions in 3D Printed Graphene-Reinforced PLA Notched Specimens Using the Average Strain Energy Density Criterion
Authors: Cicero Sergio , Arrieta Sergio 
Published: November 2023

Abstract
This paper applies a methodology in which the Average Strain Energy Density (ASED) criterion is used to estimate fracture loads on 3D printed graphene-reinforced PLA (polylactic acid) SENB (single edge notched bending) specimens containing U-shaped notches. The ASED criterion is based on the quantification of the Strain Energy Density averaged over a control volume specifically defined at the notch tip. The approach is based on the idea that failure takes place when the mean value of the elastic strain energy (W) referred to a specific volume is equal to a critical value (Wc), which may be understood as a material property. The material analyzed in this work was 3D printed with three different raster orientations (0/90, 30/−60 and 45/−45) for which tensile tests on plain specimens and fracture toughness tests on cracked specimens had been previously performed. Then, notched specimens with notch radii of 0.25 mm, 0.5 mm, 1 mm and 2 mm, were conducted to fracture, determining the corresponding experimental fracture loads. Finally, these experimental fracture loads were compared to the fracture load estimations derived from the application of the ASED criterion. The results demonstrate the accuracy of the ASED criterion for estimating fracture loads in this particular 3D printed material.
Proposal for the Design of a Dynamically Loaded Pressure Vessel With the Ratio of the Pulse Period to the Vessel Natural Vibration Period More Than 0.35
Authors: Nourani Mohamadreza , Zimmermann Joerg , Seraj Mohsen , Clayton Alan 
Published: November 2023

Abstract
In ASME BPVC Section VIII Division 3 (2021) [1], impulse loading has been defined as “a loading whose duration is a fraction of the periods of the significant dynamic response modes of the vessel components. For a vessel, this fraction is limited to less than 35% of the fundamental, membrane-stress dominated (breathing) mode”. In this article, designing a pressure vessel for a Fusion Demonstration Plant (FDP) that is exposed to pressure pulses as high as 34.5 MPa at 14.3 msec period is discussed. The vessel and the connected accumulators (gas drivers) to it have a dominant natural frequency of about 102 Hz, related to the breathing mode based on our dynamic analysis was used. The ratio of the pulse period to the natural vibration period of the vessel is 1.457. This is much higher than the 0.35 limit in the code. In this article, the design criteria are detailed, and it is proposed to be added to the ASME BPVC Section VIII Division 3.
A Critical Initial Flaw Size Analysis Approach for Cleavage Fracture in the Circumferential Welds of Layered Pressure Vessels
Authors: Kirby Matthew L. , Riha David S. , Cardinal Joseph W. , Hobbs Joel R. , Stoltz Brian C. , Melia Benjamin D. 
Published: November 2023

Abstract
The National Aeronautics and Space Administration (NASA) operates roughly 300 non-code layered pressure vessels (LPVs) constructed of steels that are at a risk of cleavage fracture during operation. NASA is currently assessing the continued fitness-forservice of these vessels and is employing computational analysis of the critical initial flaw size (CIFS) in key regions in the LPVs, such as the circumferential welds, to guide non-destructive evaluation (NDE) inspections. The NASGRO fatigue crack growth and fracture mechanics software is being used to perform the CIFS analysis. Cleavage fracture toughness varies as a function of crack-front length, but standard procedures for computing the CIFS in NASGRO assume fracture toughness is invariant to crack-front length. Thus, the CIFS analysis procedure in NASGRO was modified to account for a fracture toughness value that is dependent on crack-front length and a varying aspect ratio during the CIFS computations. This paper describes the CIFS analysis approach for cleavage fracture in circumferential welds using NASGRO and provides an example of the analysis for a postulated flaw in the shell-to-shell circumferential weld of a 9-layer exemplar vessel within NASA’s LPV fleet.
Linkage of Fracture Assessment Methodology With Fracture Toughness Testing Procedures
Authors: Cooper Adam J. , James Peter , Sharples John 
Published: November 2023

Abstract
J-Integral, J, is a commonly accepted elastic-plastic fracture mechanics parameter defined as the amount of energy released per unit area of crack surface increase. J can be calculated numerically or measured experimentally using standard test specimen geometries and internationally accepted testing standards. The former is conventionally considered for structural components containing known or postulated defects and the latter for evaluating material fracture toughness. J for the structural component can subsequently be compared with the material fracture toughness J in order to assess structural integrity. R6 is an elastic-plastic fracture mechanics methodology that is inherently based on these two J evaluations. In terms of fracture toughness evaluation, despite J being originally developed to account for crack tip plasticity, it can be challenging to measure valid values of J using conveniently sized fracture toughness test specimens — even as large as B = 25mm Compact Tension (C(T)) — when testing modern, high toughness materials due to the extent of global plasticity generated during loading.
Traditionally, fracture toughness testing procedures like ASTM E1820 have not been “linked” to structural integrity methodologies like R6 other than for the measured fracture toughness values to be “plugged” into the actual evaluations. However, in view of the fracture toughness evaluation challenges referred to above, a study has been undertaken to investigate how the validity limits specified in ASTM E1820 compare with the “plasticity” limit, specified in R6 and defined as Lrmax. The paper shows that C(T) B = 25mm specimens, tested/analysed according to ASTM E1820, produce JIc initiation toughness values residing in the Lrmax domain of the R6 Failure Assessment Diagram (FAD). This is despite the experimental JQ value being successfully qualified as JIc using the validity criteria in ASTM E1820 and J-R curves falling well below Jmax for the selected C(T) B = 25mm specimen size.
This paper highlights the potential challenges associated with measuring valid and meaningful values of fracture toughness (J) for modern high toughness structural steels, without adopting inconveniently large specimen sizes. This further indicates that that there is a potential for reported JIc values to display a specimen size sensitivity due to the anticipated global plasticity experienced during testing.
Comparison of Design Approaches on the Design Lifetime Prediction of Gaseous Hydrogen Storage Tanks
Authors: Fischer Carl , Oesterlin Heiner , Michler Thorsten 
Published: November 2023

Abstract
Stationary tubular hydrogen storage tanks often consist of parallel connected short pipes. The influence of gaseous hydrogen on the lifetime can be assessed following the German AD 2000 code (2021) for pressure vessels. The AD 2000 code proposes a crack initiation criterion based on S-N curves, which should be considered especially for newly designed storage tanks. Due to the special design of the tanks, the lifetime might be also assessed according to the ASME B31.12 (2019), which is a worldwide standard accepted for hydrogen pipelines. This paper presents a comprehensive study of the lifetime assessment of a hydrogen storage tank with the fracture mechanics-based approach of the ASME B31.12, where the influence of different input parameters (e.g. the initial crack depth and aspect ratio, stress intensity factor solution, fatigue crack growth law) are investigated. The results of the two different design philosophies from AD 2000 and the ASME B31.12 codes are compared and differences in the allowable number of loading cycles for the lifetime prediction of hydrogen storage tanks are discussed.
Probabilistic Fracture Mechanics Codes for Piping International Benchmark—Part 2: Probabilistic Comparisons
Authors: Homiack Matthew , Duan Xinjian , Wang Min , Heckmann Klaus 
Published: November 2023

Abstract
This paper is the second in a series of two papers that describe benchmark comparisons of 14 probabilistic fracture mechanics codes. The benchmark problems focus on determining the leak-before-break behavior of a nickel-based alloy weld in a large-bore piping system of a pressurized water reactor. The modeled degradation mechanism is primary water stress corrosion cracking. In Part 1, which is covered in the technical paper PVP2022-84724, the benchmark problem was deterministically analyzed with the probabilistic fracture mechanics codes using their models for crack growth rates, stress-intensity factors, crack-opening displacements, crack transition from inside surface-breaking cracks to through-wall cracks, leak rates, and crack stability. Several output quantities of interest relevant to leak-before-break behavior were compared. In Part 2, the benchmark problem was probabilistically analyzed with the probabilistic fracture mechanics codes by introducing uncertainties in key input parameters, such as the crack growth rate and welding residual stresses. The probabilities of leak and rupture as a function of time were then compared accounting for the effects of leak detection and inservice inspection. Interpretations of the probabilistic comparisons are provided to assess scatter among the probabilistic fracture mechanics code predictions. These interpretations are supported by an enhanced understanding of the different modeling approaches as gleaned from the deterministic benchmark comparisons.
Fluid-Structure Interaction Simulations to Predict Flow-Induced Vibration of Piping Due to CO2 Multiphase Flow
Authors: Pontaza Juan P. , Belfroid Stefan , Bazuin Rens 
Published: November 2023

Abstract
Fluid-structure interaction (FSI) simulations of high-pressure multiphase CO2 flow in 2-inch piping were performed to predict flow-induced piping vibration and stress. Computational fluid dynamics (CFD) was used to predict the unsteady multiphase flow in the piping and the flow-induced forces on the bends. A structural finite element model of the 2-inch piping system was loaded with the CFD-predicted flow-induced loading to predict piping vibration and stress in time domain. A one-way FSI simulation approach was adopted, where the flow interacts with the structure, but it is assumed that the vibration of the structure does not affect the flow field.
The 2-inch piping system is a high-pressure flow loop where piping vibration and stress were measured for a range of CO2 multiphase flow conditions in a test campaign aiming to characterize piping vibration responses with CO2 as the working fluid. The numerically predicted piping vibration and stress are compared against physical measurements collected during the test campaign at locations where accelerometers and strain gauges were installed. The selected flow conditions are for CO2 in gas and liquid phases with operation at a phase transition condition of 55 bara and 18°C. Simulations are performed for three flow conditions with increasing gas rate and fixed liquid rate, resulting in flows with decreasing liquid content by volume: 12.5%, 8.85%, and 6.73%. We find good agreement when comparing the predicted vibration levels against those measured by the accelerometers and find that the predicted stress is conservative relative to the stress measured by the strain gauges. The results validate the FSI predictions and instill confidence in the simulation approach, which is recognized as a powerful tool to predict flow-induced vibration of piping in multiphase systems.
Fire Assessments in Refineries, 20 Years of API 579 Part 11 Use at TotalEnergies
Authors: Le Nevé Charles 
Published: November 2023

Abstract
Fires in refineries and petroleum plants have catastrophic consequences, both in terms of human and material damage. After a fire, it is crucial to assess the extent of the damage to determine the necessary repairs and develop a timeline for restarting operations. The API 579 Part 11 [1] provides a pragmatic and efficient approach for assessing the damage to pressure vessels and piping. TotalEnergies has successfully used this document for more than 20 years. The purpose of this paper is to present the practices for investigating incidents and assessing the associated damage, including its limitations, implementation for different fire types, and necessary organization.
API 579 Part 11 recommends establishing six heat exposure zones. For metallic pressure vessels and piping, only the hot exposure zones (zones 4 to 6) are likely to result in damage, and these zones are the focus of this paper. After heat exposure zones are established, an exhaustive list of affected equipment is necessary to define dedicated inspection plans and associated assessment levels. The results of the inspection plan are then used to determine equipment acceptance, repair requirements, or replacements.