bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mitigation of Rocking and Sliding Motion of a Free-Standing Structure Subjected to Base Excitation Using Coaxial Circular Cylinders Containing Highly Viscous Liquid in Annular Spaces
Authors: Shintani Atsuhiko , Ito Tomohiro , Nakagawa Chihiro 
Published: November 2019

Abstract
In this study, the effectiveness of coaxial circular cylinders containing a highly viscous liquid in annular spaces for reduction of rocking motion of a free-standing structure is investigated both analytically and experimentally. First, an analytical model of coupled rocking and sliding motions of a free-standing structure, including the coaxial circular cylinders, subjected to seismic input was derived. The free-standing structure was modeled as a free-standing rigid body. The cylinders were attached to the bottom of the rigid body as a damping device.
We then experimentally derived the friction coefficients, inertia moments, and a damping coefficient in the rotating direction.
Furthermore, using these parameters, the effectiveness of this system in suppressing the rocking motion is investigated analytically. The proposed method was determined to be very effective in suppressing the rocking motion of a rigid body subjected to a seismic input by the experiment.
New Developments in PTFE Sheet Gaskets With Engineered Surface Profile
Authors: Drago James 
Published: November 2019

Abstract
This paper presents laboratory performance testing of new technology utilizing a textured raised pattern on filled restructured PTFE (R-PTFE) sheet gasketing. The technology published in PVP2018-84039 and PVP2018-84040 and presented in Prague1,2 examined the load retention attributes of filled PTFE sheet gaskets with hexagonal/honeycomb surface texture in a miniaturized and standard raised face flange joints. This paper will show performance characteristics and comparisons to flat traditional R-PTFE gaskets. Data is presented on leak performance based on DIN-3535-4/6 and EN 13555, deflection under compressive load, bolt load retention and ASTM F36 compression and recovery. The paper gives a summary of results from a study of PTFE gasket users expressing their needs and desires for gasket performance. Examples of current field cases from chemical processors are also be presented.
Quantification of the Conservatisms in the Flaw Acceptability Assessment of Doel 3 and Tihange 2 RPVs Containing Hydrogen Flakes
Authors: Lacroix Valéry , Dulieu Pierre 
Published: November 2019

Abstract
During the 2012 outage at Doel 3 and Tihange 2 Nuclear Power Plants, a large number of quasi-laminar indications were detected in the lower and upper core shells of the reactor pressure vessels (RPVs). The observed indications could subsequently be attributed to hydrogen flaking induced during the component manufacturing process. As a consequence, both units remained core unloaded pending the elaboration of an extensive Safety Case demonstrating that they can be safely operated. One of the most challenging parts of this demonstration was the Flaw Acceptability Assessment, aiming at demonstrating that the identified indications do not jeopardize the integrity of the reactor vessel in all operating modes, transients and accident conditions. This analysis was done by using a methodology: innovative, in line with existing ASME Code Section XI requirements, specific, sufficiently wide to be accepted and, first and foremost, conservative. Through a brief reminder of the Flaw Acceptability Assessment methodology, the paper presents the main hypotheses done for the calculation and quantifies the conservatism related to each of them. This quantification clearly highlights the reliability of final result i.e., the demonstration of the Fitness-for-Service for continued operation of both Doel 3 and Tihange 2 RPVs.
Analysis of a Flanged and Dished Head Assembly Used in a Horizontal Storage Tank
Authors: Zhao Mingxin 
Published: November 2019

Abstract
A nonstandard flanged and dished head is frequently used in the horizontal storage tank for quick and full access to the internal in oil and gas industry. The head is forged into an elliptical shape with a flat edge at its peripheral. The flat edge serves as a flange while the other mating half coming from the tank shell. The flange pair is installed within a C-shaped clamp and secured by compression bolts at its head side. A gasket is sandwiched between the mating surfaces of the flange pair to provide proper seal. While the head can be removed easily by unscrewing the compression bolts, this disintegrated structure does increase the complexity in component design and unique requirement for installation. The bolt compression load not only affects the pressure capacity of the storage tank, but also governs the stresses in flange pair and C-clamp. In this study, the flanged and dished head assembly has been modeled and analyzed by finite element method for stresses and gasket seal performance subject to installation and operation loads. Both elastic and elastic-plastic analysis has been performed. The tightening force of the bolts is examined against component stresses and gasket seal performance. Optimized bolt load is recommended based on acceptance criteria for stresses and leakage prevention.
Shakedown and Limit Analysis of 45-Degree Piping Elbows Under Internal Pressure and Cyclic In-Plane Bending
Authors: Peng Heng , Liu Yinghua 
Published: November 2019

Abstract
This paper carries out the shakedown and limit analysis of 45-degree piping elbows subjected to steady internal pressure and cyclic in-plane closing, opening and reverse bending moments by means of the recently proposed stress compensation method (SCM). Different geometries of the piping elbows and various combinations of these applied loads are investigated to create various shakedown limit and plastic limit load interaction curves. The plastic limit loads for single internal pressure and single bending moment calculated with the SCM are compared to those calculated with the twice-elastic-slope method. Full step-by-step elastic-plastic incremental finite element analyses are utilized to verify the structural cyclic responses on both sides of the curves obtained and further to confirm the correct shakedown limit loads and boundaries. It is shown that the SCM calculates the shakedown limit load accurately and possess more than 40 times the computational efficiency of the step-by-step elastic-plastic incremental method. The effects of the ratios of bending radius to mean radius and mean radius to wall thickness of the piping elbow as well as loading conditions on shakedown limit and plastic limit load interaction curves are presented. The results presented in this work provide a comprehensive understanding of long term response behaviors of the piping elbow under the combined cyclic loading and offer some essential points to be concerned for the design and integrity assessment of piping systems.
ADS-4 Pipe Vibration Evaluation During AP1000® Preoperational Testing
Authors: Nowicki Tim J. , Suddaby David A. , Donovan Joshua J. , Conn Alex , Paharia Madhur 
Published: November 2019

Abstract
Preoperational testing of the first AP1000® pressurized water reactors took place in the fall and winter of 2016. This Hot Functional Testing (HFT) included observation of vibrations throughout the piping systems, and is required to be successfully completed before fuel load.
During HFT, flow through the hot leg passes many piping intersections where instabilities such as vortex shedding create pressure pulsations. Coupling of the vortex shedding frequency and natural acoustic frequency of the piping sidebranch may lead to acoustic resonance of the system. This resonance condition is understood, but difficult to predict; therefore, the HFT plan included screening for such conditions based on ASME Operation and Maintenance of Nuclear Power Plants vibration monitoring group (VMG).
Vibration was observed in the Automatic Depressurization System (ADS) branch off the reactor coolant system hot leg that was potentially in a resonant condition. This paper details the identification, characterization, and analysis of the ADS vibration observed during HFT. Additional instrumentation was employed and data were gathered at varying conditions to determine the nature and extent of the vibrations. Demonstration of acceptable vibration levels in the ADS system was a key engineering accomplishment for AP1000® fuel load.
Tunable EOS Material Model in the Simulation of Pulsed Mercury Spallation Target Vessel
Authors: Lin Lianshan , Winder Drew 
Published: November 2019

Abstract
A pulsed spallation target is subjected to very short (∼1μs) but intense loads from repeated proton pulses. The effect of this pulsed loading on the stainless-steel target module that contains flowing mercury target material is difficult to predict. Different simulation approaches and material models for the mercury have been tried. To date the best matching simulation to the experimental data was obtained by an equation of state (EOS) material model with a specified tensile cutoff pressure, which simulates the cavitation threshold [1]. The inclusion of a threshold to represent cavitation was a key parameter in achieving successful predictions of stress waves triggered by the high energy pulse striking the mercury and vessel. However, recent measurements of strain responses of target modules showed that significant discrepancy between the measured strain and simulated value with the EOS mercury model still exists. These differences grow to irreconcilable values when non-condensable helium gas is intentionally injected into the flowing mercury. A novel EOS mercury model embedded into ABAQUS VUMAT has been investigated in this project, which introduces the concept of proportional, integral, and derivative (PID) control into the mercury EOS model. By tuning the new introduced PID parameters (Kp, Ki and Kd), we replace the specified cutoff pressure with an adjustable spring-damper-like material behavior which may better match the complex dynamics of the mercury and helium mixture. This approach is expected to reduce the gap between measured and simulated vessel strain responses. Primitive application of this tunable EOS mercury model on prototypic shape experimental target has demonstrated its capability and potential of improving mechanical behavior of EOS mercury with cutoff pressure considered.
Thermal Solutions for a Plate With an Arbitrary Temperature Transient on One Surface and Convection on the Other: Direct and Inverse Formulations
Authors: Segall Albert E. , Schoof Craig C. , Yastishock Daniel E. 
Published: November 2019

Abstract
Thick plates that are thermally loaded on one surface with convection on the other are often encountered in engineering practice. Given this wide utility and the limitations of most existing solutions to an adiabatic boundary condition, generalized direct thermal solutions were first derived for an arbitrary surface loading as modeled by a polynomial and its coefficients on the loaded surface with convection on the other. Once formulated, the temperature solutions were then used with elasticity relationships to determine the resulting thermal stresses. Additionally, the Inverse thermal problem was solved using a least-squares determination of the aforementioned polynomial coefficients based on the direct-solution and temperatures measured at the surface with convection. Previously published relationships for a thick-walled cylinder with internal heating/cooling and external convection are also included for comparison. Given the versatility of the polynomial solutions advocated, the method appears well suited for complicated thermal scenarios provided the analysis is restricted to the time interval used to determine the polynomial and the thermophysical properties do not vary with temperature.
Study on Fatigue Crack Growth Behavior of Zr702/TA2/Q345R Composite Plate With a Through-Wall Crack and a Crack Normal to Interface for SENT Specimen
Authors: Zhou Binbin , Zhou Changyu , He Xiaohua 
Published: November 2019

Abstract
In this paper, the fatigue crack growth behavior of Zr702/TA2/Q345R composite plate with a through-wall crack and a crack normal to interface for SENT specimen are studied. For the through-wall crack, the mutual interference in fatigue crack growth rate is found. The crack growth rate of the through-wall crack on both sides in Zr702/TA2/Q345R composite plate depends on the difference of stress intensity factors amplitude caused by the different positions of crack tips on both sides and the crack growth rate in corresponding homogeneous material. For the crack normal to interface, two crack propagation directions are taken into account. When crack initiates from the lower strength material side, the crack growth rate decreases to the minimum before crack penetrates the interface. After crack penetrates the interface, crack growth rate accelerates continuously. When crack initiates from the higher strength material side, the fatigue crack growth rate generally increases with the crack length. For both crack forms, all experiment results demonstrate that the crack growth rate is dependent on the competition of the stress intensity factor amplitude, the crack growth rate in corresponding homogeneous material and the interface strength. Besides, finite element results show that elastic mismatch results in a significantly change in the distribution of stress intensity factor amplitude.
Thinking on Intelligent Design, Manufacture and Maintenance of Pressure Equipment in China
Authors: Chen Xuedong , Fan Zhichao , Chen Tao , Xu Shuangqing , Ou Guofu , Tang Xiaoying 
Published: November 2019

Abstract
This paper introduces briefly China’s development plan for intelligent manufacturing, and combining with the present situation of design, manufacture and maintenance of pressure equipment, puts forward the development directions for the digitization, networking and intelligentization of pressure equipment at present and in the next decade from three aspects. The first aspect is digital control of shape and performance of pressure equipment. Taking the furnace tube as an example, the Material Genome technology is recommended for establishing the relationship between the microstructure and macroscopic performance of its material and achieve the target macroscopic performance by the adjustment of composition, phase and microstructure; then the additive manufacturing (3D printing) technology can be used to control the resulting shape of certain special structures so as to achieve the integrated shape and performance and significant improvement of its service life. The second aspect is digitization and network-based interconnection of production factors such as materials, equipment and personnel in the pressure vessel production workshop to realize intelligent manufacturing. Taking the transportable pressure vessel for instance, the real-time identification, diagnosis and control of abnormal conditions can be realized by information and communication technology during the key production processes such as baiting, cutting, forming, welding, heat treatment, and non-destructive testing; and if necessary, the suitable manufacturing resources across different enterprises and regions can be organized to achieve the flexible production and collaborative manufacturing of the components such as heads and flanges, etc. The third aspect is to achieve the real-time online integrity assurance of pressure equipment in process industries (e.g., petrochemical and electric power, etc.) by digitization and networking of risk-based inspection (RBI), fitness-for-service (FFS) assessment technologies and their corresponding database, in combination with real-time monitoring technology based on the characteristic safety parameters. Taking the reactor effluent air cooler (REAC) system as an example, this technology would enable not only the safety warning of critical characteristic parameters, but also the self-limiting and self-prevention of the flow-induced corrosion failure by linking with the distributed control system (DCS).
A Study of Flexible Magnetic Camera for Welded Tubular Joint Inspection
Authors: Choe Eunho , Lee Hoyong , Lee Jinyi 
Published: November 2019

Abstract
Liquid penetrant testing (PT), magnetic particle testing (MT) and ultrasonic testing (UT) have been used as nondestructive testing methods for the welded tubular joints of reactor cooling systems. The PT and the MT that are applied to the surface test of the specimen have been experiencing problems such as specimen contamination, hazardous chemical exposure risk for the inspector, and the inspector’s extended time in the nuclear power plant due to the long testing time (increased risk of radiation exposure). This study is about the applicability of an alternative nondestructive examination (ANDE) method to solve the aforementioned problems. According to the requirements of ANDE, the NDE technology should be applied with the same or better sensitivity and shorter inspection time than the conventional inspection methods of PT and MT. In order to satisfy these requirements, a flexible-type multi-sensor array was developed in order to scan a certain welding area and complete the inspection in a short time. The static and time-varying magnetic fields were applied to the test specimen and the magnetic flux density distribution was measured by solid state magnetic sensors. Each sensor is arranged with a spatial resolution of less than 2 mm, and the shape can be varied according to the shape of the bead. By using the measured data, the magnetic flux density distribution according to the presence or absence of defects and shapes can be visualized in real time, and stored into the database.
Optimization of Expanding Gathering Pipeline Network in Gas Fields
Authors: Yuan Meng , Liang Yongtu , Wang Bohong 
Published: November 2019

Abstract
One major problem in the progressive development of gas field is the expanding of gas gathering pipeline network, especially when the existing gathering pipeline system cannot satisfy the production requirements of the new wells. How to design the expanding scheme of the new block, and how to determine the best linking between the new wells and the existing pipeline network can be challenging for designers due to the complexity of the coupling relationship of the variables and strong nonlinearity of the hydraulic characteristics. To our best knowledge, few studies have been done on this issue.
In this study, to expand a gathering pipeline network in a gas field, an optimal design method is proposed considering the hydraulic characteristics of the network with an objective function that maximizes the yearly profit. The connection scheme of the new production wells is obtained by employing a genetic algorithm (GA). This method is applied to a real case study of a gas gathering pipeline system in China. To find the optimal parameter combination in GA, three key parameters includes population size, crossover probability, and mutation probability are tested. Moreover, we also choose the method from previous research which using minimum pipeline length as objective, and apply it on the same example for comparison. The results show superiority of our method in fully utilizing the capacity of gas field while meeting the production requirements.
Effect of Hydrogen on Tensile and Fatigue Properties of SUS301 Austenitic Stainless Steel
Authors: Iijima Takashi , Enoki Hirotoshi , Yamabe Junichiro , Kimura Mitsuo , An Bai 
Published: November 2019

Abstract
SSRT and fatigue life tests of SUS301 austenitic stainless steel were performed to examine the effect of hydrogen on the mechanical properties. Ni content of SUS301, 6.00–8.00 mass%, is lower than that of SUS304 in JIS standard for austenitic stainless steels. In the case of SSRT tests, specimens with and without hydrogen charging were tested in laboratory air at room temperature (R.T.), −45 °C, and −80 °C. The 0.2% offset yield strength (Ys) of the hydrogen charged specimens was less than 300 MPa in the tested temperature range. The tensile strength (Ts) and total elongation (El) of hydrogen charged specimens decreased remarkably. With decreasing testing temperature, fracture surface facet of the hydrogen charged specimens became dominant. Therefore, the effect of hydrogen on the tensile properties of SUS301 is supposed to be large. Specimens with and without hydrogen charging were fatigued in laboratory air at R.T., and specimens without hydrogen charging were fatigued in 100 MPa hydrogen gas atmosphere at R.T. Number of cycles (Nf) at finite fatigue life region of the hydrogen charged specimens and of the specimens tested in hydrogen gas were two orders shorter than that of the specimens tested in air. However, the finite fatigue life region of the hydrogen charged specimens and the specimens tested in hydrogen gas showed a different profile. Additionally, ferrite equivalents of all fatigue tested specimens and fatigued fracture surface morphology suggested the fatigue fracture mechanism between the hydrogen charged specimens tested in air and the non-charged specimens tested in 100 MPa hydrogen gas seems to be different. Therefore, further investigations are required to clear this difference.
Finite Element Analysis of Printed Circuit Heat Exchanger Core for Creep and Creep-Fatigue Responses
Authors: Mahajan Heramb P. , Hassan Tasnim 
Published: November 2019

Abstract
Printed circuit heat exchangers (PCHEs) have a high heat transfer coefficient which makes them a suitable option for very high temperature reactors (VHTRs). ASME Section VIII design code provide PCHE design rules for non-nuclear applications. The PCHE design methodology for nuclear applications is yet to be established. Towards developing the ASME Section III code rules, this study started with the PCHE design as per section VIII. An experimental set up is developed to evaluate the designed PCHE for creep and creep-fatigue performances. This study performed pretest finite element analysis to estimate experimental responses and failure loads for setting up the experiments. Three dimensional isothermal analyses of the PCHE’s were conducted by using an advanced unified constitutive model to simulate the creep-fatigue interaction. The sub-modeling technique was used to analyze the channel scale response of the PCHE. Analysis results indicate that the failure may be governed by the channel corner responses, which is influenced by the creep-fatigue interaction. Analysis based creep-fatigue damage curve is plotted as per ASME code to evaluate the design of PCHEs for nuclear application.
Low-Cycle Fatigue of Base-Plate-to-Shell Connection in Uplifting Liquid Storage Tanks Under Seismic Loading
Authors: Chatzopoulou Giannoula , Karamanos Spyros A. 
Published: November 2019

Abstract
Unanchored steel tanks, subjected to strong seismic loading, may exhibit base plate uplifting. Under repeated uplifting, the welded connection of the tank base plate with the tank shell (a fillet-welded connection) is subjected to strong cyclic deformation, involving reverse plastic loading, and this could lead to failure of the welded connection in the form of low-cycle fatigue cracking. In the present paper, an experimental program is described, supported by numerical finite-element simulations. The tests are aimed at investigating the mechanical response of small-scale welded specimens, representing the connection of the base plate with the tank shell, subjected to uplifting loading conditions. The research has been partially supported by European research project INDUSE-2-SAFETY, on the seismic safety and resilience of critical components in industrial plants.