bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Analysis of Dynamic Operations of the Main Steam Relief Isolation Valve Used in Nuclear Power Plants
Authors: Zhou Weihao , Zong Chaoyong , Li Qingye , Jiang Songzhi , Liu Yanliang , Song Xueguan 
Published: November 2023

Abstract
Main steam relief isolation valve (MSRIV) is one type of advanced control valve used in pressurized water reactors (PWR), such as Hualong One (HPR 1000 in China) and European Pressurized Reactor (EPR). It can provide overpressure protection for the steam generator (SG) and used for waste heat discharging. However, MSRIV may show undesirable operations such as reclose slow under high pressure & temperature conditions (e.g., 8.9 MPa & 316 °C) and/or cannot be opened timely under low pressure & temperature conditions (e.g., 0.14 MPa & 316 °C). To explore the root causes of these undesirables, an experimental based analysis was specially carried out in this paper. For valve performance measurement, an experimental test rig was developed, thereby not only dynamic responses of the MSRIV under different operating conditions, but also the influence of valve key parameters can be analyzed. The results show that both the system pressure and the throttle area have great influence on the dynamics of the MSRIV. Upon the same disk throttle area, the valve opening time decrease with the inlet pressure, while the valve reclosing time increase with it. For the same inlet pressures, larger throttle area usually led to longer valve opening time and the shorter valve closing time. The results obtained in this study not only provide a reference for the valve early design stage, but also can be used as a criterion for the subsequent numerical modeling works which is of great importance for the flow details acquisition and valve mechanism exploration.
Explosive Hydrocode Modeling and Proof Testing of the HsERA-26 Containment Vessel
Authors: Tribble Megan , Ludwigsen John , Stofleth Jerome , Fleming Darryn 
Published: November 2023

Abstract
An inherited containment vessel design that has been used in the past to contain items in an environmental testing unit was brought to the Explosives Applications Lab to be analyzed and modified. The goal was to modify the vessel to contain an explosive event of 4g TNT equivalence at least once without failure or significant girth expansion while maintaining a seal. A total of ten energetic tests were performed on multiple vessels. In these tests, the 7075-T6 aluminum vessels were instrumented with thin-film resistive strain gages and both static and dynamic pressure gauges to study its ability to withstand an oversize explosive charge of 8g. Additionally, high precision girth (pi tape) measurements were taken before and after each test to measure the plastic growth of the vessel due to the event. Concurrent with this explosive testing, hydrocode modeling of the containment vessel and charge was performed. The modeling results were shown to agree with the results measured in the explosive field testing. Based on the data obtained during this testing, this vessel design can be safely used at least once to contain explosive detonations of 8g at the center of the chamber for a charge that will not result in damaging fragments.
The Effects of Fluid Working Conditions on Flange Face Corrosion
Authors: Hakimian Soroosh , Bouzid Abdel-Hakim , Hof Lucas A. 
Published: November 2023

Abstract
The second most common cause of hydrocarbon leakage is corrosion in offshore platforms. In seawater and hydrocarbon services, bolted flange joints can be susceptible to corrosion at their flange face. The current work considers corrosion of bolted flanged gasketed joints using the COQT fixture (COrrosion Quantification Test) to evaluate corrosion in flange faces. According to the literature, both crevice corrosion and galvanic corrosion widely occur in bolted flanged gasketed connections, creating leakage paths of the pressurized fluid. Leakage failure in bolted flanged gasketed joints can cause hazards to the environment and human safety. Corrosion in bolted gasketed joints was investigated in the literature. However, these studies do not consider the influence of the operating parameters such as fluid flow, pressure, pH, conductivity, temperature, and gasket contact pressure.
With the developed COQT fixture, which was introduced in the previous paper, different electrochemical techniques can be applied to measure flange corrosion under controlled test conditions. The polarization technique will be used to measure and compare the corrosion rate of flange at different fluid flow rates, and gasket contact stresses. The flange sample material is ASTM A105, and the gasket material is Teflon. Electrochemical tests are conducted with a solution of 3.5% NaCl. Confocal microscopy is used to visualize the morphology of the damaged zones on the surface, and localize and quantify the pits size caused by corrosion, respectively. Comparing the results of the electrochemical tests and the microscopic studies will identify the most influent factor on the corrosion rate of flanges.
Blister Damage Evolution in Plastic Liner of Type IV Hydrogen Storage Vessel Studied by Fracture Mechanics
Authors: Shi Hao , Peng Wenzhu , Wei Liqing , Kang Qiubing , Chen Qi , Hua Zhengli 
Published: November 2023

Abstract
Type IV vessels are widely used for high-pressure hydrogen storage onboard vehicles due to their advantages in lightweight, durability, economy, etc. However, the plastic liner of type IV vessel is likely to blister, which can further cause the liner to fracture and hydrogen leakage. Many types of research have revealed that blistering in the plastic liner occurs when the vessel is depressurizing. High-pressure hydrogen diffuses through the liner and occupies the preexisting cavities inside it, causing cracking-like blisters under internal pressure in the cavities when external pressure decreases. A model based on fracture mechanics was deployed to predict the blister damage evolution in the plastic liner. The blister damage propagation was evaluated by the stress intensity factor, which is related to the high-pressure hydrogen acting on the cavity. The blister damage evolution inside the plastic liner with different materials was studied. Besides, the effects of the depressurization rate, the cavity location, and the number of cavities on blister damage were also studied. The kinds of materials play an essential role in blister damage evolution. It was found that the material with increased tensile properties prevented crack growth better. The external pressure acting on the liner affects the size of crack growth in the blistering process. And the damage varies with the location and number of cavities. The interaction between cavities could change the stress field in the liner, which affects crack growth.
Evaluation of the Fracture Toughness of Short Carbon Fiber Reinforced Thermoplastic Composites
Authors: Shi Jianfeng , Zong Xinwei , Jiang Weili , Yao Riwu , Zheng Jinyang 
Published: November 2023

Abstract
Short carbon fiber reinforced thermoplastic composites (SCFRTCs) are widely applied in aerospace, transportation, shipping, and other fields because of their excellent mechanical properties and high recyclability. The fracture toughness, which is an essential characteristic of the resistance of materials to crack propagation, is considered a critical aspect of the long-term performance of SCFRTCs structures. In this work, the fracture toughness of SCFRTCs is characterized through three-point bending tests. The stress intensity factor KIC of SCFRTCs is calculated, and the influence of short carbon fiber (SCF) fraction on the fracture toughness is investigated. The strain field during the crack propagation process in the three-point bending test is measured and analyzed by digital image correlation (DIC) method. Scanning electron microscope observation is carried out to investigate the mechanism of SCFs in the micro-cracks initiation and propagation. The results demonstrate that a higher SCF fraction increases the fracture toughness of SCFRTCs, which is expressed as the maximum increase of 73.7% when the SCF fraction is 9.8 wt%. Furthermore, it is found that adding SCFs reduced the strain level at the crack tip, and the SEM observations suggest that SCFs played a bridging role on both sides of the crack. Overall, the results of this study confirm that SCFs can inhibit crack propagation and thus improve the fracture toughness of SCFRTCs.
A Review on Hydrogen Production From Ocean Renewable Energy and the Application Status
Authors: Shi Jianfeng , Xia Ruoxi , Zheng Xingyu , Yao Riwu , Zheng Jinyang 
Published: November 2023

Abstract
Ocean renewable energy development is strategically significant to the world’s low-carbon energy transformation. Many ocean renewable energy development projects have been carried out or are under planning. Combining green hydrogen and ocean renewable energy is ideal for developing ocean renewable energy. This paper first surveyed the main ocean renewable energy hydrogen production projects worldwide. Detailed information about these projects’ technical routes and the scale of renewable energy development were then summarized. With ocean renewable energy development gradually moving towards greater offshore distance and water depth, large-scale and low-cost ocean renewable energy development has become a critical concern in industry and academia. Therefore, a comparison about the energy transmission mode is then carried out. Furthermore, based on the current ocean renewable energy development projects, the development trend of hydrogen production from ocean renewable energy was analyzed, including increased offshore distance and water depth, development of floating wind platforms, and large-scale wind turbines. Meanwhile, the main technical challenges are discussed in detail to achieve large-scale and low-cost ocean renewable energy development.
Fatigue Crack Growth Analysis in Pipe Fittings Using Finite Element Analysis
Authors: Radhakrishnan Harish , Manuel Jacob 
Published: November 2023

Abstract
The finite element method is used to study the fatigue crack growth in a T-joint pipe fitting. We show the convenience of the method to model fatigue crack growth when an initial crack is in a section of pipe where, simplification to standard geometry sections is not possible or is difficult. The conventional Paris-law is used to govern the crack growth. After evaluating fracture parameters on the initial crack, the number of cycles needed to advance the crack by an incremental size is computed. The direction of crack growth is calculated by assuming the incremental growth happens in the maximum circumferential stress direction. The fracture topology is modified accounting for crack growth and the process of computing fracture parameters and incrementally growing the crack is repeated. The method is robust and can account for fracture growth under residual stress fields commonly seen in areas welded areas. We demonstrate the versatility of the method and its use in computing fatigue fracture growth for pressurized equipment under a variety of structural and thermal loads.
Elastic-Plastic Analysis for Crossover Piping by Using ASME Code Case N-900 and JSME Code Case NC-CC-008
Authors: Shibukuwa Kenichi 
Published: November 2023

Abstract
In 2019, two remarkable code cases (ASME CC-N900[1]/JSME NC-CC-008[2]) regarding seismic design method by elastic-plastic analysis were published by ASME/JSME almost simultaneously. However, there are few practical applications by both code cases in actual seismic design work. In the case of seismic design of crossover piping across the building isolation boundary, which are supported at many points, the seismic design of crossover has the difficult issue to be addressed and it is necessary to resolve overstressed piping due to both large seismic anchor movements and large seismic inertia forces. It is difficult to resolve this issue and perform the rational seismic design by current ASME code cases. This paper recommends the specific seismic design rules for crossover piping, based on fatigue evaluation example of EPRI PFDRP TEST-30 by both code cases (ASME CC-N900/JSME NC-CC-008) and provides the results of study regarding the technical issues of elastic-plastic analysis to develop the rational seismic design rules in the future.
Reliability of a Composite Lined Pipe for Trenchless Rehabilitation of Thermal Pipelines Based on a Two-Heating-Season Long Field Test in China
Authors: Wang Yingdi , Yan Shuo , Zeng Xiangjing , Zhang Liang , Shi Jianfeng 
Published: November 2023

Abstract
The advantages of trenchless rehabilitation of underground pipelines in construction and maintenance costs have been widely acknowledged. In this work, a two-heating-season (∼5800 h) long field test was carried out to verify the reliability of thermal pipeline rehabilitation using a composite structure of lined pipe in a thermal station in China. The average working temperature and pressure ranges in the primary heat network are 90 °C and 0.5 MPa, respectively. The critical mechanical and thermal properties of the materials are analyzed and compared before and after the field test. The results show that the melting temperature and crystallization temperature have increased by 0.6 °C and 3.1 °C, respectively. Further, there is no obvious degradation in weight in the working temperature range of the thermal pipeline network. The tensile strength has been increased by 71.38% after the field test, and only a 2.44% decrease in fracture strength was observed. The results indicate that the composite lined pipe is still available for application in the thermal pipe in the working condition of the present work.
Study on the Applicability of GTN Model on Fracture Evaluation for Plate Specimen With a Surface Crack Using a BWR Reactor Pressure Vessel Material
Authors: Ogawa Takuya , Hayashi Takahiro , Yoshida Shuichi , Itatani Masao , Saito Toshiyuki 
Published: November 2023

Abstract
Cases of stress corrosion cracking (SCC) in Ni-base alloy weld metals welded to the low alloy steel (LAS) in reactor pressure vessel (RPV) components have led to discussions on the possibility of SCC propagating into the RPV. The JSME Fitness-for-Service code provides fracture evaluation methodology based on linear elastic fracture mechanics for SCC into the RPV, assuming neutron irradiation in the RPV beltline region. It is considered, however, more rational methodology of fracture evaluation can be applied to the RPV components such as a bottom head component of boiling water reactor (BWR) since the effect of neutron irradiation is considered to be negligible. In the previous studies, the fracture mode of RPV material has been investigated by using a large-scale, heavy forged steel part named “bottom head ring”, manufactured for a recent BWR. The authors reported that the results of fracture tests showed ductile failure and the fracture loads evaluated using the elastic-plastic fracture mechanics (EPFM) methodology have showed fairly good agreement with the maximum loads in the fracture tests on plate specimens with a semi-elliptical surface crack.
In the present study, the applicability of damage mechanics analysis by using Gurson-Tvergaard-Needleman (GTN) model, which can analyze ductile fracture behavior due to nucleation, growth and coalescence of voids in metallic materials, to fracture evaluation for a RPV bottom head component of BWR was investigated. GTN model parameters of the tested material were investigated by comparison of the relationship between load and load-line displacement (LLD) obtained by the JIc fracture toughness tests with that obtained by finite element analysis (FEA) using GTN model. And a set of GTN model parameters that can reproduce the load-LLD relationship by the tests were determined. Fracture analysis for the plate specimens with a semi-elliptical surface crack were performed by using the GTN model parameters determined. It was found that relationship between load and crack mouth opening displacement (CMOD) obtained by the FEA showed a good agreement with that obtained by the fracture tests of the plate specimens. Furthermore, the fracture behavior observed in the FEA using GTN model also showed good agreement with that in the fracture test, such as necking behavior on the plate specimens, ductile crack extension traces on the fracture surfaces and crack penetration. The results obtained in the present study totally supported the applicability of the GTN model to RPV bottom head component.
Development of a New Thermo-Mechanical Load and Fatigue Monitoring Approach Based on Electromagnetic Acoustic Transducers - EMUS-4-STRESS
Authors: Weikert-Müller Miriam , Weber Fabian , Thieltges Sascha , Smaga Marek , Silber Fabian , Rudolph Jürgen , Bergholz Steffen , Bechtgold Eduard 
Published: November 2023

Abstract
Fatigue monitoring systems based on direct global and local temperature measurements are successfully being applied in facilities worldwide. Local temperature measurement is carried out by way of thermocouples on the outer wall of piping sections close to fatigue relevant components. The detectability and re-solvability of the corresponding inner wall temperatures — required for the fatigue assessment — is limited in the case of fast and high frequency load cycles occurring e.g. due to non-stationary mixing or vortex penetration processes of cold and hot flows. These kind of limitations are motivation for the development of a complementary nondestructive system using electromagnetic acoustic transducers (EMATs) in order to measure the ultrasonic time-of-flight (TOF).
Recent results of a respective cooperative R&D project (Fraunhofer IZFP Saarbrücken, RPTU Kaiserslautern-Landau, MPA Stuttgart, Framatome GmbH) on the applicability of the electromagnetic acoustic transducer technology for the purpose of fatigue monitoring will be discussed in this paper. The validation of the method was realized under various laboratory and operational conditions on different test rigs (uniaxial standard fatigue tests, component bending tests, pressurized pipe tests, heated plate tests, heated pipe tests, fluid structure interaction FSI test facility at MPA Stuttgart). A new test rig at the Framatome premises allowed for the simulation of different temperature transients and the application of thermocouple based and EMAT based measurements. Furthermore, both measurement types were applied at the MPA fluid structure interaction (FSI) test rig for a realistic cold-hot mixing scenarios.
It is the final aim of the project to determine the time history of fatigue relevant loading at fatigue relevant locations as the basis for complex fatigue monitoring according to the formula fatigue monitoring = continuous load monitoring + periodic (or continuous) engineering fatigue assessment.
Experimental Investigation of Combined Axial Flow and Jet Cross-Flow on PWR Mock-Up Array
Authors: Gad-el-Hak Ibrahim , Mureithi Njuki , Karazis Kostas 
Published: November 2023

Abstract
Some pressurized water reactors (PWRs) are designed to relieve the pressure increase in the barrel-baffle region associated with a loss of coolant accident (LOCA). Flow holes, called LOCA holes, are introduced in the baffle plates to equalize the pressure difference between the core side and the barrel-baffle region. However, it has been found that jet flow emanating from LOCA holes induces fretting wear of the fuel rods at the spacer grid position during normal operation. The effect of jet in transverse flow (JITF) on a PWR mock-up array should be investigated in order to determine the rod array response and, as a result, to set safe operating conditions for these reactors.
This research looks at the effect of axial flow velocity on the stability of a single-span 6 × 5 square rod bundle having a prototypical fuel assembly dimensions in some designs of pressurized water reactor cores. The axisymmetrically flexible rods in the highly compact array are instrumented with four strain gauges to measure the two-dimensional rod displacements. Then, the response of the rod bundle under combined flows (i.e. JITF) is measured for three test axial flow velocities, VAxial = 1.0 m/s, 1.5 m/s, and 2.0 m/s. The experimental results show that the critical jet cross-flow velocity increases with the axial flow velocity. This is attributed to the bending effect of axial flow on the jet flow (i.e. jet trajectory). The critical flow velocities are collected to provide a stability map of the arrays subjected to the jet in transverse flow.
Geometrical Effect of Tube Array on Prediction of Fluidelastic Instability – Single Phase Air Flow
Authors: Elhelaly Amro , Weaver David , Riznic Jovica R. , Hassan Marwan 
Published: November 2023

Abstract
Flow-induced vibrations (FIV) are a major consideration in the design of shell and tube heat exchangers. Among the FIV excitation mechanisms, fluidelastic instability (FEI) is by far the most important mechanism that can significantly compromise the structural integrity of tube arrays. Traditionally, FEI was thought to only occur in the transverse direction. The recent tube failures of replacement steam generators showed that FEI could occur in the streamwise direction and be equally devastating. This has sparked intensive efforts to uncover the nature of this new phenomenon.
The current work presents an experimental investigation program which was initiated to systematically uncover fundamental aspects of this phenomenon. Experiments were carried out in an airflow wind tunnel at the University of Guelph in the Fluid-Structure Interaction Laboratory. The aim of this study was to investigate the geometrical effect of tube array types on the FEI in both the transverse and streamwise directions. The stability of a single flexible tube and multiple flexible tubes in tube arrays were tested. Parallel triangle and normal triangle arrays were tested at pitch ratios in the range of 1.25 to 1.7. A compression between the available experimental data and the current result was presented and conclusions were drawn. The results show that the stability threshold is sensitive to the pitch-to-diameter ratio of the array and the number of flexible tubes especially in the streamwise direction.