bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Dynamic Recrystallisation on the Fatigue Life of the Out-of-Plane Gusset Welded Joint Treated by Ultrasonic Impact Treatment
Authors: Yamaguchi Atsushi , Togasaki Yu , Honda Takashi , Sasaki Tetsuya 
Published: November 2024

Abstract
An ultrasonic impact treatment (UIT) is a peening method, commonly used as a post-weld treatment to improve the fatigue strength of welded joints. In this study, fatigue tests were conducted on out-of-plane gusset welded joints treated with UIT, comparing their fatigue life to that of as-welded (AW) joints to assess the effects of UIT on fatigue life. The material used for the out-of-plane gusset welded joints was WEL-TEN 950PE. UIT was found to increase the fatigue life of WEL-TEN 950PE by more than tenfold. The improvement in fatigue life attributed to UIT, is believed to stem from the introduction of compressive residual stress, alleviation of stress concentration at weld toes, and grain refinement beneath the weld toes. Three-dimensional elastic stress analysis showed that the stress concentration factor Kt at the weld toe decreased from 3.3 to 2.5 as the UIT transfers the shape of the needle tip to the weld toe. Additionally, residual stresses measured by X-ray stress analysis showed a shift from a maximum tensile residual stress of 300 MPa to a compressive residual stress of 650 MPa. Microstructural observation using laser microscopy revealed that the grain structure of WEL-TEN 950PE was refined from the surface to 300 μm, by UIT.
Experimental and Numerical Analyses for the Evaluation of Hydrogen As an Energy Source for Thermal Testing of Transport Packages of Radioactive Material
Authors: Naster Maximilian , Gleim Tobias , Wille Frank 
Published: November 2024

Abstract
In this paper we present a new hydrogen-based test rig for an ongoing feasibility study of using hydrogen as an energy source for the thermal testing of transport packages containing radioactive materials. The test rig will be capable of combusting hydrogen for a wide range of different burner geometries, mass flows and if necessary hydrogen blends. As this type of fire test according to the IAEA [1] boundary conditions does not yet exist, a large number of preliminary investigations, safety assessments and calculations must be carried out in order to develop a viable concept for hydrogen fires. In the first step of the feasibility study, the temperature, structure, and radiation of various hydrogen flames are surveyed. In future works, the results will make it possible to design burner frames that are suitable for fire reference tests in order to make comparisons with pool and propane fires used in assessment procedures today, cf. [2]. In parallel comparative numerical simulations are conducted to model the thermal behaviour of hydrogen flames using the software package Ansys® [3]. On the one hand, the numerical simulations support the experiments by providing an overview of numerous parameters and the measuring range; on the other hand, they will help with the design of the burner frame in future work. This paper gives an overview in the design and capabilities of the test rig. Furthermore, the results of the parameter studies show that burner geometry and mass flow provide a significant design margin for the thermal shape of the hydrogen flames. In addition, the results of the initial numerical calculations will be used to determine the necessary sensors, the positions, and their operating range. Only the optimal interaction allows a controlled system that permits user-defined hydrogen fires.
A Review of Check Valves in Unsteady Flow: Behavior, Analysis, and Design
Authors: Lang Scott , Schreuder Jans , Witte Dylan , Dudley Mark 
Published: November 2024

Abstract
Check valves intend to prevent reverse flow with minimal impact to normal forward flow. They respond to transient conditions, and improper selection may result in unmitigated check valve slam — causing massive transient pressure surge that can easily cause damage throughout the connected piping network.
Dynamic characteristics show the dependence of closure velocity on fluid deceleration. This paper aims to clarify, summarize, and qualify the use of these curves in liquid flow. Computer simulation models and examples are described along with comparisons to field data. Basic design principles, guidelines for identifying at-risk systems, and strategies for check valve selection are presented.
Predicting Acoustically Vibration Induced Resonance From Modal Analysis
Authors: Arjunan Raj , Niu Yaying , Ghosh Arindam , Karzcub Denis 
Published: November 2024

Abstract
Preliminary results from experiments and finite-element models for a joint industry project (JIP) to investigate acoustically induced vibration (AIV) have been presented in past conferences. The dynamic stress concentration ratio (DSCR) was found to vary significantly between modes (namely in the 0–400Hz frequency range) although it was unclear how this should be applied to quantify overall dynamic stress levels and the risk of fatigue failure. More detailed assessment of the experimental data has confirmed the presence and significance of low-frequency higher-order structural modes (0–400Hz) with a significantly higher DSCR and the strong forced excitation of these structural modes below the cut-off frequency of higher-order acoustic modes (i.e. higher-order structural modes excited by planar acoustic modes below the acoustic cut-off frequency of higher-order modes). These observations lead to a need to extend the study of AIV of piping to cover planar acoustic modes in addition to the traditional consideration of only higher-order acoustic modes. Fundamental to this is the need to address risk factors associated with low-frequency pipe modes with very high DSCR under conditions (namely high gas flow velocity and high flow capacity orifice plates) in the presence of significant low-frequency planar acoustic modes. Finite element analysis is used to show the nature of the modes, locations, and levels of highest dynamic stress and how this relates to the boundary condition effects of a structural discontinuity such as a branch connection or pipe support. The strong excitation of planar acoustic modes is likely to be particular to piping with geometry leading to quarter and half wavelength acoustic resonances such as those experienced in the sub-header of the JIP test arrangement. Some preliminary results from acoustic modal and structural-acoustic harmonic analysis are also presented as a supporting activity to quantify the nominal overall increase in dynamic stress associated with low-frequency AIV.
Rapid Fault Diagnosis of LNG Receiving Terminal Transportation Operation Process Based on SOM-KPCA
Authors: Xiao Shangrui , Hu Jinqiu , Zhang Laibin 
Published: November 2024

Abstract
Accurate and rapid diagnosing, identifying and locating faults in LNG terminals are essential for ensuring the safe functioning and high-quality output of LNG terminals. The use of intelligent data-driven fault diagnosis methods has received extensive attention. Nevertheless, conventional data-driven fault diagnosis methods require a large amount of annotated data and historical events, resulting in huge labor and time costs. In this paper, an unsupervised and rapid fault diagnosis method is proposed for the external transportation operation of LNG terminals based on Self-Organizing Map and Kernel Principal Component Analysis (SOM-KPCA). The SOM-KPCA fault diagnosis model is used for dimensionality reduction and clustering with the real-time monitoring label-free data of the LNG terminals. The fault diagnosis boundary conditions are set based on the system high and low alarm threshold, data association, temporal trends, and eigenvalues, and fault diagnosis is performed on a cluster basis. By removing the necessity for data annotation and historical event observation, the SOM-KPCA fault diagnosis model significantly reduces the amount of time needed to diagnose faults. For example, in the low-pressure pump and high-pressure pump pressurization transportation process of an LNG terminal’s export operation, the accuracy of SOM-KPCA fault diagnosis reached 86.21%, with a precision rate of 90.38%. Rapid fault diagnosis in the LNG terminal’s export operating process is made possible by a significant reduction in both the computational complexity of fault diagnosis data and the SOM-KPCA clustering time, as compared with SOM clustering without dimensionality reduction.
Optimizing Coke Drum Keyhole Dimensions Using Statistical Modeling
Authors: Fernando John , Kwok Henry , Chan Luke , Penso Jorge 
Published: November 2024

Abstract
To extend the fatigue life of coke drum skirt-to-vessel attachment welds, keyholes have become an important consideration in skirt design. The amount of stress reduction they offer to the weld depends on the geometric specifications of the keyholes, namely the slot dimensions, relief-hole diameter, and the distance between the top relief hole and the top of the skirt. Although the directional impact that varying each keyhole parameter has on stress reduction can be intuited, the exact functional relationships are not well established. This results in significant computational efforts at the design stage to iteratively rank keyhole designs based on fatigue-life performance. To help mitigate the need for extensive simulations, the current study investigates a large parameter space of keyhole designs for two commonly used skirt designs to identify functional trends between keyhole parameters and stress. The functional relationship in certain cases is found to be not only non-linear, but also non-monotonic. However, the variation in stress reduction is well-predicted through simple linear regression models when the parameter space is constrained to include only keyhole dimensions typically used in coke drum designs for various practical reasons. The resulting regression models have the potential to significantly reduce computational efforts when optimizing coke drum skirt designs.
Research and Application of Crude Oil Storage Tank Integrity Management
Authors: Qi Sheng , Shuai Jian , Li Yuntao , Shi Lei , Mei Yuan , Ren Wei 
Published: November 2024

Abstract
Crude oil storage tanks are subject to corrosion and settlement due to their location in coastal areas, resulting in leaks, fires and explosions. In order to secure crude oil storage tanks, a crude oil storage tank integrity management system with safety target as the core and eight elements such as management process and inspection technology as components is proposed to guide the integrity management of crude oil storage tanks throughout their life cycle for the first time. The cyclic process of storage tank integrity management with data acquisition, risk assessment, integrity assessment, decision response and efficiency evaluation as the main steps is formed and applied as a method of integrity management implementation. The effectiveness of crude oil storage tank integrity management was verified within the oil depots in China. The results show that the integrity management system is effective and the risks of 38 storage tanks are accurately characterized. The integrity of the storage tank is accurately analyzed by relevant standards and finite element models. Finally, decision response measures and efficiency evaluation methods are obtained. Crude oil storage tank integrity management can provide significant support information for managers on how to optimize risk management strategies and achieve limited resource allocation.
Numerical and Experimental Study of Detection of Linear Damage of Pressure Equipment Using Electromagnetic Acoustic Resonant Method
Authors: Wang Zhe , Fan Zhichao , Tang Jian , Cheng Jingwei , Ji Tian , Wang Haibin , Bu Yangguang 
Published: November 2024

Abstract
Currently, the application of electromagnetic ultrasound methods in damage detection such as corrosion thinning of pressure equipment is constantly expanding. It has the advantages of non-contact, no couplant and non-polishing required. However, the detection accuracy is limited by low energy transfer efficiency and time-domain signal distortion at high temperatures environment. Combining electromagnetic ultraosnic testing and acoustic resonance methods, a multi-period signal excitation transducer is used to obtain the frequency-domain resonance information of the test piece, which can effectively improve the energy intensity of echo. This paper firstly establishes an electromagnetic acoustic resonance (EMAR) detection model based on the magneto-electric-force-acoustic transduction mechanism. Then, the sound field distribution and time/frequency domain response characteristics of EMAR was studied and a magnetically concentrated transducer is designed. Flat-bottom holes are used as the detection standard of corrosion thinning in this paper. Based on the developed EMAR detection system, the experiments for detection of flat-bottom holes and thickness measurement at high temperature environment were carried out. The correlation between local corrosion thinning and transducer size has been proven. The measurement error of wall thickness at 500°C and atmospheric pressure of 1 bar using EMAR method is within ±0.1mm. This study lays a foundation for quantitative detection and monitoring applications of damage to pressure equipment with high temperatures or corrosion layers.
Dependence of Blast Shielding on Stand-Off Distance
Authors: Geng Jihui , Thomas Kelly 
Published: November 2024

Abstract
A key component of hazard evaluations involving explosions is the determination of hazard zone boundaries, which includes evaluation of standoffs to given blast overpressure values and the associated building damage. Many such evaluations use a simplified methodology which assumes that the blast wave propagates from the explosion source to the target location without interacting with intervening buildings or structures (i.e., without blast wave shielding). This is obviously a perfectly acceptable approach for a screening study, but blast wave shielding effects can be significant in certain circumstances (e.g., within a building group). In addition, the blast shielding effect depends on blast wave parameters (overpressure and duration) and structural dimensions. It is well known that the blast overpressure decreases with stand-off distance while blast positive duration increases with increasing stand-off distance. This paper extends the prior work, focusing on the determination of the blast shielding as a function of standoff distance. Only the high explosive (HE) source was examined in this study as there is a definite single blast chart to characterize the blast parameters vs scaled distribution.
Numerical Study of a C-ring in a Bimetallic Joint of a Cryogenic Propellant Tank
Authors: Rose K. A. Jesna , H. M. Umer , Nair Remya , Thomas Suresh Mathew , Asraff A. K. 
Published: November 2024

Abstract
In the realm of cryogenic pressure vessels, bolted flanged joints employ a spring-energized C-ring mechanism to achieve a leak-tight seal. The application of clamping force during the torquing process compresses the C-ring, generating adequate sealing pressure. The different thermal expansion behaviours of mating surfaces and C-rings in a cryogenic environment can affect contact pressure at the C-ring. Moreover, these joints must endure external pressures and vibrational loads, exacerbating the relaxation of the C-ring and contributing to potential leaks. This study delves into a numerical simulation of a bimetallic joint operating in a cryogenic environment under varying pressure loads. A more comprehensive and accurate simulation of a standard C-ring is conducted, and the obtained outcomes are cross-referenced against experimental data in the existing literature. Furthermore, an extensive nonlinear finite element simulation is performed to fathom the linear load (C-ring load per unit circumference) fluctuations experienced by a C-ring in a bimetallic joint of a cryogenic pressure vessel, as well as the effects of external pressure loading. The findings highlight a reduction in sealing pressure at the contact area when subjected to cryogenic pressure loads. Nevertheless, the relaxation arising from both cryogenic conditions and external pressures remains within permissible thresholds. These results are subsequently validated through an LN2 pressure test applied to a simplified version of the joint configuration.
Theoretical Analysis of Natural Frequencies and Mode Shapes of Piping Systems With Tees
Authors: Tamura Shinji 
Published: November 2024

Abstract
The vibration of piping system subjected to earthquake is a severe problem. However, the actual piping system is seems to be too complicated to analyze theoretically. Therefore, the finite element method is used to obtain the natural frequencies and mode shapes. Recently, the author have proposed the theoretical analysis method for the piping system with elbows, which is extended from Leissa and Qatu’s approach. In this method, the connection conditions at the elbows derive the characteristic equation of the piping system. In this paper, the proposed approach is further extended for the piping system with tees.
The Use of a Carbon Fibre Reinforcement System for the Mitigation of Acoustically Induced Vibration
Authors: Middleton Chris , Swindell Rob , Borland Gordon , Holstad Ole , Van Der Kooij Kari 
Published: November 2024

Abstract
Mitigation of acoustically induced vibration (AIV) on ‘live’ flare systems poses a series of challenges; any modification should be non-intrusive and, also, wherever possible, avoid hot work (e.g. welding).
This paper describes a series of tests, sponsored by Equinor ASA, which were performed on a full-size steel alloy piping spool using specialist facilities at the University of Southampton, UK, to quantify the effectiveness of carbon fibre reinforced polymer wrap in mitigating the high frequency structural response of the pipe to broadband high frequency acoustic excitation. The objectives of the tests were (i) to establish the potential benefit in terms of the dynamic stress reduction with increasing wrap thickness, and (ii) obtain valuable damping and modal data for the purposes of validating finite element predictions.
Conclusions are drawn concerning the results obtained and the lessons learned, along with other key practical considerations. Recommendations are also drawn regarding further qualification testing.
Enabling the Use of Carbon Steel for CO2 Transport, Processing, and Intermediate Storage
Authors: Rensman Jan-Willem , Krom Alfons 
Published: November 2024

Abstract
Anthropogenic CO2 in the atmosphere must be lowered to keep global warming to a minimum. Avoiding CO2 production will be essential, but capturing CO2 from process streams may contribute to a faster decrease. CO2 impurities must be removed to allow cost efficient use of engineering materials such as carbon steels. After drying and sufficient purification, CO2 becomes an essentially non-corrosive fluid.
The operating conditions are not particularly challenging from a structural integrity point of view. However, there are transient conditions that need to be addressed.
The paper will focus on enabling the use of carbon steel for gaseous CO2 transport piping, liquefaction plants, compressor stations, intermediate liquefied CO2 storage, and long-distance transport piping. The paper will present a European perspective on low temperature design with carbon steels since the European codes facilitate low temperature design with fracture-mechanics-based methods. The paper will address threats from internal low temperature transient conditions due to depressurizing and repressurizing, cooling in and around holes and orifices, and design against running fracture in high pressure pipelines.
Fatigue Behavior in Air of 316L Stainless Steel Obtained by Additive Manufacturing in the Frame of the NUCOBAM European Project
Authors: Guilbert Séverine , Doremus Luc , Chitty Walter-John , Hermant Alexandre , Quibel Jonathan 
Published: November 2024

Abstract
Additive Manufacturing (AM) opens new opportunities for the nuclear industry by reducing manufacturing costs for complex geometries compared to traditional manufacturing methods. Nevertheless, it should be verified that components obtained by AM meet the performances needed regarding safety-related function and operational requirements as the usual materials used in the nuclear industry. The NUCOBAM (Nuclear Components Based on Additive Manufacturing) European project aims at developing a methodology to qualify components produced via AM. Laser Powder Bed Fusion and the austenitic stainless steel 316L are the AM method and the material under study for this project.
One of the major mechanical degradation mechanisms undergone by nuclear materials is fatigue. Therefore, one of the key points of NUCOBAM’s material characterization program is the low cycle fatigue behaviour in air of the AM processed 316L. A complete test matrix has been designed including several strain amplitudes between 0.2% and 1% and test temperatures (room temperature or 300°C). The other parameters under study are the machining direction (resulting in z-oriented or x-oriented specimens), the porosity ratio, the grain structure, the specimen post processing heat treatment, and the thermal ageing heat treatment. This paper aims at giving an overview of the fatigue test program results and discuss them in the light of microstructural characterizations. A comparison of the fatigue mean curve from NUREG/CR-6909 rev1 obtained for wrought stainless steel is discussed.
This study was performed on behalf of the NUCOBAM European project that received funding from the Euratom 2014-2018 under grant agreement No 945313.
Delayed Hydride Cracking Initiation Evaluation of a Fretting Flaw in a CANDU Reactor Zr-Nb Pressure Tube With Consideration of Finite Length of the Flaw and Flaw Shielding Effect
Authors: Scarth Douglas , Xu Steven , Doddihal Preeti , Kawa Dennis , Ip Monique 
Published: November 2024

Abstract
In-service evaluation of a flaw that is detected in a Zr-Nb alloy pressure tube in a CANada Deuterium Uranium (CANDU) nuclear reactor includes an analysis to demonstrate that delayed hydride cracking will not initiate from the flaw. The flaw can be assessed either as planar or volumetric with a blunt root radius. A flaw caused by fretting due to flow-induced vibration was detected by ultrasonic examination in a Zr-Nb alloy pressure tube in a CANDU nuclear reactor. The flaw was replicated to obtain details of flaw geometry. The flaw is volumetric in nature, and is comprised of two axially oriented features that were joined by a ligament. This flaw was evaluated for delayed hydride cracking initiation in accordance with the Canadian Standards Association Standard N285.8. Two-dimensional elastic finite element stress analysis of the flaw was performed. An adjustment factor on the applied stress that took into account the finite axial length of the flaw was used to produce a lower and more representative peak flaw-tip stress as compared with an assumed “infinite” length of the flaw in the two-dimensional finite element stress analysis. The proximity of the two features of the flaw generated a stress shielding effect which was also accounted for in the evaluation for delayed hydride cracking initiation. The flaw met the acceptance criteria for prevention of delayed hydride cracking initiation, and the pressure tube was returned to service. This paper provides a summary of the delayed hydride cracking initiation evaluation of this flaw, and highlights the methods adopted to reduce conservatism in the evaluation.