bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on the Mechanical Response of Gas Cylinders Under Shock Load
Authors: Fang Zhou , Wu Gang , Song Ce , Yuan Jun , Wang Zhe 
Published: November 2023

Abstract
In order to ensure the safe operation of pressure vessel cylinders in the service stage, the mechanical response law of gas cylinders under dynamic load under different working conditions is clarified. In this study, numerical simulation was used to study the different shock loads of gas cylinders at different positions. The finite element analysis results of the impact load of the cylinder when the sphere and cone are used as the percussive objects are compared and analyzed, and it is concluded that the steel cylinder will cause obvious deformation of the cylinder as a whole when subjected to the impact load, and the maximum deformation position is located at the top head or the connection between the top head and the cylinder. Because of the presence of the saddle, the shock load acts on the bottom head, and the equivalent force distribution is mainly distributed in the lower half of the cylinder. When acting on the cylinder or the connection between the cylinder and the top head, the equivalent force is distributed throughout the cylinder, but regardless of where the shock load is applied, the maximum equivalent force occurs at the connection between the cylinder and the saddle, where the stress concentration is generated. The cylinder bears the impact load applied by different percussive objects, the incidence speed increases, the maximum deformation and equivalent force generated by the cylinder increase, and there are also certain differences in the value when the cylinder bears the impact load applied by the sphere and the cone, indicating that when the cylinder bears the impact load, the type of percussion has a certain impact on the equivalent force of the cylinder.
Study on Anti-Instability Inflation Pressure of Vehicle-Mounted Type Ⅳ Hydrogen Storage Cylinder
Authors: Liu Zezhong , Chen Zhiwei , Jia Xiaoliang , Ji Fang 
Published: November 2023

Abstract
In this paper, the 70 Mpa vehicle-mounted type IV hydrogen storage cylinder fully wound by carbon fiber with plastic liner is studied. Based on the analytical method, the analytical analysis model of fiber-wound hydrogen storage cylinder is built to obtain the functional relationship between fiber winding parameters and the external pressure of the liner. In addition, the critical buckling load of the hydrogen storage cylinder liner is obtained through the finite element method. The mapping relationship between fiber winding parameters and anti-instability inflation pressure is constructed; a calculation method of anti-inflation pressure in the process of fiber winding of type IV hydrogen storage cylinder is proposed, and the effect of inflation pressure with the increase of fiber winding layer is studied. The calculation method of inflation pressure can provide theoretical guidance for the selection of inflation pressure in the manufacturing process.
On the Quantification of Accidental Gas Release From Pressurized Vessels
Authors: Rosti Annalisa , Brunesi Emanuele , Dacarro Filippo , Dubini Paolo , Marino Alessandra , Nosenzo Giorgio , O’Reilly Gerard J. 
Published: November 2023

Abstract
NaTech accidents may pose significant risk to human safety, not only for potential structural and non-structural damage but also considering the possible release of hazardous substances into the environment. In the context of risk-based management of industrial facilities, the detection and quantification of accidental release of toxic substances from pressurized pipelines and tanks are thus of primary concern. Based on these considerations, this paper presents a simplified analytical model for assessing the accidental release of gas from pressurized vessels. Taking advantage of pressure and temperature measurements acquired by fiber-optic (FO) sensors, the proposed model allows for quantifying the mass outflow rate, averaged in a given time window, and for estimating the leakage area. To this end, the model is capable of identifying the time at which the discharge process starts and following its evolution over time. The capability of the proposed analytical model is demonstrated by comparing predictions with results from several experimental tests, specifically carried out for simulating the release of gas from a vessel, pressurized at different initial pressure thresholds and equipped by FO sensors. Estimates from the developed analytical model can be also exploited for assessing concentrations of chemicals in the industrial plant and simulating their spatial diffusion over time, thus supporting the generation of environmental health risk maps.
Master Curve Evaluation Using Miniature C(T) Specimens as Part of a Round Robin Program Within the FRACTESUS Project
Authors: Naziris Frideriki , Hernandez Pascual Rebeca , Metzler Timo , Gaganidze Ermile , Uytdenhouwen Inge , Kolluri Murthy 
Published: November 2023

Abstract
Surveillance testing is the basis for all reactor pressure vessel (RPV) integrity and lifetime assessments to evaluate the validity of the RPV embrittlement trend curve used for a specific reactor. Most of the standard surveillance programmes, do not contain sufficient number of surveillance specimens for beyond the original design life of 40 years. Thus, testing methods based on small / sub-sized specimens are considered. Experimental programmes on un-irradiated RPV steels have proven that miniature compact tension (∼4*10 *10 mm3) specimens, mini-CT, can successfully be used for fracture toughness characterization in the transition regime to determine reference temperature (T0) based on the master curve method. However, application of miniature testing techniques on irradiated materials in hot cells comes along with several technical challenges such as remote controlled machining, application of the extensometers, manipulator sensitivity, accurate sample geometry measurement etc. In addition, the optimal test temperature range for obtaining valid KIc values for the mini-CT specimen is narrow and consequently sufficient number of specimens should be tested to guarantee a reliable valid T0-value.
Within the FRACTESUS project, European and International efforts are joined to establish the foundation of small specimen fracture toughness validation and demonstration to achieve change in code and standards allowing to address the various national regulatory authority concerns. As part of the third work package (WP3), high-fluence fracture toughness data, on well characterized RPV materials, will be produced to serve as input for the guidelines of future testing.
To assure the robustness of the testing procedures to the difference in testing machines or operators, a round robin (RR) exercise on un-irradiated materials is organised among the partners of WP3. This work presents the preliminary results of the mini-CT fracture toughness data on un-irradiated RPV SA508 Cl. 3 material which was independently tested by four institutes: CIEMAT, KIT, SCK CEN and NRG. All four institutes determined T0 according to the ASTM E1921 standard and the results are compared and discussed.
A Comprehensive Sample Problem for Section III Division 5 Design by Elastic Analysis
Authors: Barua Bipul , Messner M. C. 
Published: November 2023

Abstract
High temperature advanced nuclear reactor technologies could play an important role in moving the U.S. towards a zero-carbon future. Efforts to transform the U.S. nuclear industry have entered the full bloom, energized by billions of dollars in funding through the Department of Energy’s Advanced Reactor Demonstration Program (ARDP). New reactors in the U.S. will most likely be designed to the ASME Boiler & Pressure Vessel Code, Section III, Division 5 rules for safety related components in elevated temperature service. The goal of this paper is to provide the reactor designers with a comprehensive sample problem, detailing the step-by-step design calculations in Section III, Division 5, design by elastic analysis rules. The sample design problem is a 316H pressure vessel with a nozzle, similar to the pressure vessel and primary inlet nozzle in the intermediate heat exchanges of the Clinch River Breeder reactor plant. The sample problem considers several Service Level-A (normal condition) and Service Level-B (upset condition) loads. The sample problem uses Multiphysics Object Oriented Simulation Environment (MOOSE), an open source finite element Code developed by Idaho National Laboratory, for thermal and structural analysis. For design calculations, the sample problem utilizes U.S. Nuclear Regulatory Commission’s software package “ASME Section III, Division 5 Design Tool”, originally developed at Argonne National Laboratory.
Post Irradiation Examination of Pressurized Water Reactor Stainless Steel Internal Components
Authors: Lach Timothy G. , Chen Xiang (Frank) 
Published: November 2023

Abstract
Internal structural components of pressurized water reactors (PWR), such as baffle former bolts, are subjected to significant neutron irradiation and mechanical stresses at elevated temperatures during plant operation. Over the long operation of the power plant, these conditions lead to potential degradation and reduced load-carrying capacity of these bolts. To understand property degradation more fully, to confirm the results of experimental irradiation programs, and to predict operational lifetime performance of structural materials in internal components, post irradiation examination of harvested materials from operating nuclear reactors is required. In this work, two high fluence 316 stainless steel baffle former bolts were retrieved from a commercial Westinghouse two-loop downflow type PWR and then sectioned for analysis via mechanical testing and microstructural characterization. The irradiation damage fluctuated along the bolt length with damage levels from 15 to 41 displacements per atom with the bolt head receiving approximately twice the neutron damage levels as that of the bolt thread section. Mechanical testing evaluations showed extensive irradiation hardening and a sharp decrease in fracture toughness in all parts of the bolt, though with limited variation along the bolt length. Microstructural characterization using analytical scanning transmission electron microscopy and atom probe tomography showed significant radiation induced precipitation, segregation, and dislocation loop and cavity formation. However, unlike the mechanical behavior, there was considerable variation along the bolt length but opposite of what may be expected, with more precipitation and cavity formation in the bolt thread where the neutron radiation dose is less than in the bolt head where the neutron radiation dose is higher. The cause of this variation is likely due to gradients in temperature, neutron energy spectra, and gamma irradiation.
Probabilistic Fracture Mechanics Evaluation of PWR Cast Austenitic Stainless Steel Piping Components – Axial Cracking Methods and Results
Authors: Fuhr Kevin , Wolfson Matt , White Glenn , Burkardt Markus , Shim Do Jun 
Published: November 2023

Abstract
The material microstructure of cast austenitic stainless steel (CASS) materials challenges the reliability of ultrasonic examination techniques, particularly detection of axial cracks and depth sizing of circumferential cracks. As such, the qualification requirements for ultrasonic examination of CASS piping in accordance with the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC), Section XI, Mandatory Appendix VIII, have not been developed.
In addition to the limitations of ultrasonic testing (UT) examination, CASS material is subject to thermal aging, which causes degradation of its fracture toughness over time. The extent of toughness degradation depends on the ferrite phase (δ-Fe) content of the particular component.
A probabilistic fracture mechanics (PFM) approach was applied to support development of examination requirements in light of the current nondestructive examination (NDE) limitations for CASS components. The PFM evaluations were performed using a software code developed specifically for this purpose called PIPER-CASS. This paper describes the approach and results obtained for postulated axial cracking (e.g., from a preexisting fabrication flaw) in CASS piping. This work is intended to support development of ASME BPVC, Section XI, Mandatory Appendix VIII, Supplement 9, for CASS and an alternative to the current Section XI, Subarticle IWB-2500 (Examination Categories B-F and B-J) examination requirements specific to CASS piping.
Combined Hydrogen Embrittlement and Strain Rate Sensitivity of Annealed and Forged 304L Steel
Authors: Wheeler Robert W. , Ronevich Joseph , San Marchi Chris , Foulk James W. , Diab Mazen , Alleman Coleman 
Published: November 2023

Abstract
In this work, the combined effects of strain rate and internal hydrogen (from gaseous precharging) on the tensile properties of 304L austenitic stainless steel in both annealed and forged conditions are characterized. Due to its high corrosion resistance, strength, and formability, 304L has a wide variety of applications, including pressure vessels, valves, and other manifold components. While both the strain rate sensitivity and hydrogen effects on 304L have been reported in the past, the combined influence of internal hydrogen and strain rate on the tensile flow curves has not been studied. To better understand these effects, uniaxial tensile tests were performed at strain rates varying between approximately 10−2 and 10−5 per second both with and without internal hydrogen. The combined influence of strain rate and internal hydrogen on the tensile flow curves and strain-induced martensite are reported and discussed. It was found that the 0.2% offset yield stress increased with increasing strain rate for both conditions (with and without internal hydrogen), at nearly a constant rate per decade. Additionally, for the annealed material, the relative change in stress was shown to be approximately equivalent (an increase of 45 MPa) when comparing the fastest strain rate (10−2 /s) with the slowest rate (10−5 /s) for both with and without internal hydrogen. The influence of internal hydrogen on rate dependent parameters are also discussed for the forged 304L.
Numerical Analysis of Permanent Deformation in Pressure Vessels due to Weld Overlay
Authors: Dandekar Akshay , Gordon Andrew , Kulkarni Mandar 
Published: November 2023

Abstract
Pressure vessels are regularly exposed to corrosive chemicals and oxidizers, which could cause loss of material from the vessel internal diameter and reduced wall thickness. Weld overlay (WOL) is performed to deposit a material layer on either the internal or external surface to compensate for lost material so that the pressure vessel satisfies API 579 Fitness for Service guidelines to remain safely in service. In addition to being a remediation for general and local metal loss, WOL may also be performed to restore wall thickness after grinding out crack like flaws developed in pressure vessels. The WOL process deposits a layer of molten material on the remaining shell base material. During this process, the base material shows rapid heat buildup, which is then subsequently dissipated through conduction and convection. The change in the temperature causes localized expansion and contraction of shell, which induces thermal stress and permanent deformation. It is important to analyze the permanent deformation as it can impact the performance of the pressure vessel. In addition, the material buildup also results in a change in the shell geometry and hence API 579 – 4.6.2.4 also recommends performing a follow up analysis to ensure continued acceptability of the design [1].
Several factors such as material composition, material melting point, weld speed, weld zone thickness, voltage, thickness of existing and deposited material can affect the resulting thermal stress and permanent deformation. Tests to analyze the impact of these parameters are expensive in terms of time and money and, thus, computer simulations could be advantageous. In addition, a computational parametric approach could also help identify optimal overlay patterns, which would minimize shell distortions while minimizing overall process costs.
This study presents four different approaches to analyze the effect of weld overlay on the thermal stress and permanent deformation in the pressure vessel. Both sequentially coupled and fully coupled thermal-mechanical approaches are analyzed and compared. The effect of these approaches on the permanent deformation and its impact on the RSF (remaining strength factor) of the structure are studied. The method introduced could further be expanded to perform parametric studies to understand the effect of each input parameter on the permanent deformation in the pressure vessel at the end of weld overlay along with its impact on the overall acceptability of the structure post the remediation process.
Experimental Investigation on the Pull-Out Strength of Flexibly Expanded Tube-to-Tubesheet Joints
Authors: Ma Xin , Dong Wenli , Wang Xiaoliang , Ge Zhiqiang 
Published: November 2023

Abstract
Mechanics and technical points of flexible expansion process of tube-to-tubesheet joints in shell-and-tube heat exchangers were briefly introduced. A series of experiments were performed on flexibly expanded tube-to-tubesheet joints to verify the pull-out strength. Carbon steel 20 and stainless steel S30408, two kinds of materials frequently used as tube in heat exchanger construction in China, are employed in the experiment. Specially developed rubber expansion equipment was employed to simulate the flexible expansion process in the experiment as well. Grooves with different widths and depths were used to investigate their influence on the pull-out strength. The results show that the pull-out strength of tube-to-joints with no annular ring grooves in tube holes grows with the increase of expanding pressure during the initial stage of expanding process, and the growth approaches naught when the expanding pressure reached a certain value. Compared with the ungrooved tube-to-tubesheet joints, the pull-out strength of the grooved ones is much higher and can well satisfy the requirements specified in China code & standard at the experimental conditions. The width of groove has remarkable effects on the pull-out strength of joint, and an optimum width of groove exists for a given pipe specifications. Especially, the expansion degree recommended in Chinese standard for heat exchanger is not suit for flexibly expanded tube-to-tubesheet joints.
Identification of Typical Damage Mechanism of Coke Drum in Delayed Coking Unit
Authors: Ma Xin , Xie Yi , Ge Zhiqiang 
Published: November 2023

Abstract
Coke drums are large pressure equipment critical to the delayed coking unit (DCU) of refineries, which are used for the carbonization reaction involving dehydrogenation, rearrangement and polymerization. Due to the complexity of the internal process medium, the variability of structure and severe operation loads, many potential damage mechanisms may occur in the in-service coke drums. Failures such as corrosion, bulging and local thinning of the drum body; cracking at the connection between outlet nozzle and drum body and the fillet weld in skirt-to-conical head joints have been frequently found. Therefore, it is very important for a pressure vessel inspector to identify the exact potential damage mechanisms at a specific place of the coke drum. In this article, typical damage mechanisms of coke drum in delayed coking unit are identified according to the component content of internal process medium, the construction materials of the coke drums, and the structure features of the vessel. The main characterizations, the crucial influencing factors, and the control measures are put forward as well. Based on some inspection examples of coke drums, the causes of typical failures and the corresponding inspection and detection methods are given to provide reference for pressure vessel inspectors and periodic inspection of coke drums.
Meridional Direction Limits for Local Primary Membrane Stress Between Sm and 1.1Sm
Authors: Sulwinski Rafal , Li Qi , Johnston Rusty , Kilambi Sreelatha 
Published: November 2023

Abstract
BPVC Section VIII Division 2 defines primary membrane stress in a region of stress as local if the distance over which equivalent linearized stress exceeding 1.1 Sm does not exceed √(Rt) in the meridional direction. Current edition of BPVC Section VIII Division 2 code does not define meridional distance for primary membrane stress between Sm and 1.1 Sm. As a result, users are forced to treat the region between Sm and 1.1 Sm as general primary membrane stress which leads to a potential for failure in stress analysis or the need to use more costly elastic-plastic analysis.
Existing research and data by Ferry et al. on ASME Section III in 1983 indicate that there is a need to address meridional distance where stress is below 1.1 Sm [1]. Currently there are no limits on meridional distance when localized primary membrane stress is between Sm and 1.1 Sm. This paper presents possible scenarios with lower primary membrane stress. Considering the same stress gradient (the change in stress to the change in meridional distance) permissible in current edition of the code, this paper suggests meridional distance limits 1.25√(Rt) when maximum local primary membrane stress is between Sm and 1.1 Sm.
Stress Relaxation Cracking, A Misunderstood Problem in the Process Industry
Authors: Rensman Jan-Willem , Spindler Mike W. , Shargay Cathleen 
Published: November 2023

Abstract
Many high temperature material failures in pressure equipment in the chemical and refining process industry have been attributed to Stress Relaxation Cracking (SRC) or Reheat Cracking (RC) as it is called in the UK. SRC/RC failures are being reported frequently in the literature [1][2][3][4][5], in spite of construction in accordance with high temperature design codes for pressure equipment. Very few preventive measures have been incorporated in process equipment design codes.
Several SRC/RC theories have been proposed [4][7][6]. The mechanism is often described in terms of a degraded microstructural state before damage starts to accumulate. This has not led to predictions on if or when failure occurs, although somewhat successful mitigation strategies [8][9] have been defined, which involve heat treatments of materials and fabricated structures.
In this paper, the current understanding of in-service SRC/RC will be summarized with a primary on austenitic stainless steels and Nickel alloys. It will be explained why some mitigation strategies work and what are the practical implications for the process industry. The usefulness of various testing programs for alloy characterization and susceptibility ranking will be briefly discussed, and the paper will highlight the capabilities of the UK nuclear power industry’s R5 “Assessment Procedure for the High Temperature Response of Structures” [10] for the prediction of SRC/RC.