bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Study on Scale Effect of KCS
Authors: Zhou Yujie , Liu Liwei , Cai Xiao , Feng Dakui , Guo Bin 
Published: November 2019

Abstract
The key objective of this paper is to perform a fully nonlinear unsteady RANS simulation to predict the self-propulsion performance of KCS at two different scales. This simulations are performed at design speeds in calm water, using inhouse computational fluid dynamics (CFD) to solve RANS equation coupled with two degrees of freedom (2DOF) solid body motion equations including heave and pitch. The SST k-ω turbulence equation is discretized by finite difference method. The velocity pressure coupling is solved by PISO algorithm. Computations have used structured grid with overset technology. The single-phase level-set method is used to capture the free surface. The simulations of self-propulsion are based on the body-force method. The PID control method is applied to match the speed of KCS by changing the propeller rotation speed automatically. In this paper, the self-propulsion factors of KCS at two scales are predicted and the results from inhouse CFD code are compared with the EFD date, and then the reasons for the scale effect have been discussed.
CFD-Based Numerical Wave Basin for FPSO in Irregular Waves
Authors: Baquet Aldric , Jang Hyunchul , Lim Ho-Joon , Kyoung Johyun , Tcherniguin Nicolas , Lefebvre Timothee , Kim Jang 
Published: November 2019

Abstract
Following the successful application of CFD-based Numerical Wave Basin (NWB) to GBS, TLP and Semisubmersible platforms [1–4], the same methodology has been applied to simulate FPSO hull motion responses to irregular waves. It has been found that the NWB modeling practices developed for the other floater types must be modified for application to an FPSO. This paper describes how the NWB modeling practices have been improved, and then compares results from NWB simulations with those from physical model testing.
OpenModelica Modelling of the Thruster in a Compact Subsea Work-Class Remotely Operated Vehicle
Authors: Xing Yihan , Fotland Kristian , Ong Muk Chen 
Published: November 2019

Abstract
Thrusters are vital for the functionalities of remotely operated vehicles (ROVs). The development of thruster design is a trade-off between cost, thrust force, physical weight and size. A six degree of freedom model is created in OpenModelica to investigate the vibrations and bearing responses in thruster systems. The model consists of a marine propeller, a shaft, and two bearings. The propeller used is based on the Wageningen B-screw propeller series. The hydrodynamic added mass and damping forces are calculated from empirical equations based on open water tests and are functions of the propeller geometry, rotational speed and fluid density. Meanwhile, the mean thrust and torque are obtained from open water test data of the relevant propeller and are used to calculate the dynamic forces and moments from the marine propeller. Displacements in the axial, horizontal, and vertical directions are calculated and used to investigate vibration amplitudes and bearing life.
Initial steady-state simulations show that the bearing life of the bearings in the thruster is found to be highly dependent on the axial load acting on the bearing, i.e., the thrust force. Moreover, if the propeller is not balanced then high centrifugal forces can occur and result in severe forces in the radial direction which can be of concern regarding the bearing life.
Performance of Semi-Metallic Gaskets With Nubbins
Authors: Taylor Robert , Fairbanks David 
Published: November 2019

Abstract
Nubbins are predominately machined into a heat exchanger flange to create a high stress point to produce a tighter seal.
Traditionally the gasket used when a nubbin is present is a Double Metal Jacket (DMJ), which consists of a metal jacket with a soft internal sealing material e.g. Graphite, PTFE. The metal jacket is commonly soft iron, carbon steel or a 300-series austenitic stainless steel.
This paper will compare the performance of a DMJ and Kammprofile gasket, performance being – leakage and temperature cycling and the affect the nubbin has on the gasket after testing.
RPV Irradiation Surveillance Programmes in China
Authors: Zhang Shuo , Zhang Haisheng , Sun Kai 
Published: November 2019

Abstract
Nowadays, nuclear energy is very important to China. Since Qinshan phase I nuclear power plant, by the end of December 2018, 44 nuclear power units are in operation in the mainland of China, with a total power rate of 44645MW, all these units are pressurized water reactors except for two CANDU6 heavy water reactors of Qinshan phase III. The power rate of those units under construction is 16,921MW, and most of them are also pressurized water reactors. Pressurized water reactor is a proven reactor type, but the safety problems should always be paid close attention to, one of the problems is the safety of the reactor pressure vessel (RPV). RPV is the key component in determining the lifetime of pressurized water reactor nuclear power plants, because it is subject to the significant aging phenomenon of irradiation embrittlement and can not be replaced. For materials used for the RPV, sufficient strength and toughness are required to endure the operating conditions and the aging degradation. In order to ensure the safety of RPV, the international experienced practice is to set up the irradiation surveillance programme, including the design of the irradiation surveillance capsule, the irradiation surveillance program, the irradiation surveillance test and evaluation. This paper introduces the RPV irradiation surveillance programmes on pressurized water reactors in China.
Applicability of Seismic Fatigue Evaluation by JSME Code Case, NC-CC-008
Authors: Otani Akihito , Nakamura Izumi , Watakabe Tomoyoshi , Morishita Masaki , Shibutani Tadahiro , Shiratori Masaki 
Published: November 2019

Abstract
A Code Case, JSME S NC1, NC-CC-008, in the framework of JSME Nuclear Codes and Standards has been published. New seismic evaluation methodology for piping by utilizing advanced elastic-plastic response analysis method and strain-based fatigue criteria has been incorporated into the code case. It can achieve more rational seismic design than the current rule.
This paper demonstrates validity and applicability of fatigue evaluation method proposed in the code case. Experimental results of a shaking table test for a piping model is used for comparing the evaluation by the current rule with one by the code case. As a result, it is confirmed that the code case can provide a rational and conservative result in the fatigue evaluation of piping. Moreover, cycle counting in the fatigue evaluation was examined for further progress of the code case.
Effects of Initial Pressure and Length of a Broken Pipe on the Transient Hydraulic Loads Acting on Nuclear Steam Generator Tubes and Supports During Blowdown Following a Sudden Feedwater Pipe Break
Authors: Jo Jong Chull , Jeong Jae-Jun , Yun Byong-Jo 
Published: November 2019

Abstract
This paper investigates the effects of steam generator initial pressure and length of a broken feedwater pipe on the transient hydraulic loads on the pressurized water reactor (PWR) steam generator (SG) tubes and supports during blowdown following a sudden feedwater line break (FWLB). To do this, the transient flow fields inside the SG and the connected broken feedwater pipe are calculated by realistically treating the discharge flow as the sub-cooled water flashing flow. Then, the calculated transient flow field data are used to predict the transient hydraulic loads on the PWR SG tubes and supports for some specified cases where the SG initial pressure or the broken feedwater pipe length are different from each other.
How to Select the Optimized Time Step and Mesh Size for FEM Thermal Transients Simulations of PWR Vessels and Nozzles by Means of Artificial Neural Networks
Authors: Santucho Nicolas , Chimenti Martin , Duo Jose 
Published: November 2019

Abstract
This paper describes the development of a data base and associated interpolation tool used to perform the validation of FEA thermo-mechanical models designed to verify the structural integrity of a self-pressurized modular Reactor Pressure Vessel (RPV) and its nozzles under service transient thermal loads. The main goal is to assess the element’s size and time steps that provide a confidence level on the obtained solutions.
The validation process implies the definition of the geometry under study, its material’s properties, thermal load conditions and type of mesh element. With all this information, the program gives the user a set of curves for maximum time steps vs. temperature change rates for each typical thickness section in the modeled geometry for a chosen element size. Any point located below those curves assures a solution underneath a user specified allowable error (e.g.: 5%).
All calculations are processed using dimensionless variables in order to create a universal data base enabling the analysis of many different situations of geometries, materials and loads. To improve performance, an Artificial Neural Network algorithm was developed. The resulting application significantly reduces the convergence study time and efforts.
New Code Case Development for the Mitigation of PWSCC and CISCC in ASME Section III Components by Advanced Surface Stress Improvement Technology
Authors: Cho Sungwoo , Mohr Nicholas , Pyun Young Sik , Amanov Auezhan , Broussard John 
Published: November 2019

Abstract
A challenge for owners operating nuclear power plants and spent fuel canisters is to provide sound technical basis for the safety and security of long-term operation and storage, respectively. Two code cases N-729-6 and N-770-5 provide performance requirements for mitigation of Primary Water Stress Corrosion Cracking (PWSCC) in ASME Section XI and Code Case N-860 “Examination Requirements and Acceptance Standards for Spent Nuclear Fuel Storage and Transportation Containment Systems” is under development in ASME Section XI. The primary degradation concern being addressed in N-860 is Chloride Induced Stress Corrosion Cracking (CISCC). ASME Section III has formed two Task Groups with the intent to reduce PWSCC and CISCC in operation by mitigating residual stresses during new construction of components.
ASME Section III formed Task Group Weld Residual Stress (TG-WRS) to incorporate lessons learned into the Code from operating plants regarding their experience with stress corrosion cracking. An example of expected guidance from TG-WRS is to consider residual stresses after weld repair of a susceptible material when the repair surface is exposed to the wetted environment. To address this concern, one form of mitigation could be the use of SSI which has been used in operating plants. However, there is a gap because no acceptance or performance criteria exists for mitigation of SCC by surface stress improvement for ASME Section III components.
The executive committee of ASME requested that a new Task Group named “Advanced Surface Stress Improvement Technology” (ASSIT) be formed by the Korean International Working Group (KIWG) and Materials Fabrication and Examination (MF&E) to address this gap by developing a code case for mitigation of PWSCC and CISCC for new ASME Section III components by SSI techniques. This paper will discuss the background and current approach being taken by Task Group ASSIT in developing SSI acceptance or performance criteria for mitigation of SCC. The necessary technical reports supporting this code case are also under development as part of joint projects between Doosan Heavy Industries and Construction (DOOSAN), Electric Power Research Institute (EPRI), and Sun Moon University (SMU). Interim reports summarizing the status of these joint projects will be presented as separate papers in the same session.
Mean Stress Correction for Fatigue Life of Carbon Steel: Proposal of Non-Closure Model
Authors: Kamaya Masayuki 
Published: November 2019

Abstract
Influence of the mean stress on fatigue life was investigated for carbon steel. Uni-axial fatigue tests were conducted by stress and strain-controlled conditions at room temperature. The fatigue life was reduced by applying the mean stress for the same stress amplitude. The fatigue life exhibited better correlation with the strain range rather than the stress amplitude. Increase in strain range caused by applying the mean stress correlated well with the decrease in the fatigue life. It was assumed that the mean stress effect on the fatigue life was brought about by the change in crack growth rate caused by applying the mean stress. The mean stress enhanced crack mouth opening and accelerated the crack growth. The non-closure model, in which the crack mouth is assumed not to be closed even at the minimum peak stress, was proposed.
A Kriging-Based Surrogate Model for Seismic Fragility Analysis of Unanchored Storage Tanks
Authors: Phan Hoang Nam , Paolacci Fabrizio , Corritore Daniele , Tondini Nicola , Bursi Oreste S. 
Published: November 2019

Abstract
The seismic vulnerability of aboveground steel storage tanks has been dramatically proved during the latest seismic events, which demonstrates the need for reliable numerical models for vulnerability and risk assessments of storage facilities. While for anchored aboveground tanks, simplified models are nowadays available and mostly used for the seismic vulnerability assessment, in the case of unanchored tanks, the scientific community is still working on numerical models capable of reliably predicting the nonlinearity due to uplift and sliding mechanisms. In this paper, a surrogate model based on a Kriging approach is proposed for a case study of an unanchored tank, whose calibration is performed on a three-dimensional finite element (3D FE) model using a reliable design of experiments (DOE) method. The verification of the 3D FE model is also done through a shaking table campaign. The outcomes show the effectiveness of the proposed model to build fragility curves at a low computational cost of the critical damage state of the tank, i.e., the plastic rotation of the shell-to-bottom joint.
A Thermal-Mechanical Analysis Model for Composite Overwrapped Pressure Vessel for Hydrogen During Fast Filling
Authors: Jiang Y. , Xu M. , Fan Zhichao , Xuedong Chen , Wu Q. G. 
Published: November 2019

Abstract
Composite overwrapped pressure vessel (COPV) is considered to be the most promising storage tank for hydrogen. Filling the COPV to high pressure within 3–5 minutes generates temperature increment due to negative Joule-Thomson coefficient and compression effect of hydrogen. This temperature increment induces a non-uniform temperature distribution in the COPV. The difference between the physical properties of inner metallic liner and outer composite will produce thermal stress. In this work a computational fluid dynamics (CFD) model is built to simulate the temperature increment during fast filling of the COPV. A three-dimensional thermal-mechanical finite element model for COPV is set up. The temperature distribution of the COPV by the CFD model is input into the thermal-mechanical model to analyze the stress distribution during the fast filling. This thermal-mechanical analysis model will provide technical support for the design of COPV.
Limit Load Solutions of the Orthotropic Thick-Walled Pipe Subjected to Internal Pressure, Bending Moment and Torsion Moment
Authors: Xu Min , Zhao Yujie , Zhou Binbin , He Xiaohua , Zhou Changyu 
Published: November 2019

Abstract
Based on the Hill yield criterion, the analytical solutions of the limit load of orthotropic thick-walled pipes under pure internal pressure, bending moment and torsion are given respectively. The simplified Mises analytical solution and finite element results of limit load for isotropic thick-walled pipe are obtained. The solution verifies the reliability of the analytical solution. The paper discusses the difference of limit load of isotropic and orthotropic pipes under the conditions of pure internal pressure, pure bending moment and pure torsion moment. It is concluded that the influence of material anisotropy on the limit load is significant. The limit load of pipe under pure internal pressure is mainly determined by circumferential yield strength, pure bending is only related to axial yield strength and pure torsion moment is related to the yield strength in the 45° direction and radial yield strength.
Random Excitation PSD Model Acting on Heat Exchanger Tube Bundle Under Two Phase Flow Condition
Authors: Nishida Shingo , Kawakami Ryoichi , Hirota Kazuo , Morita Hideyuki , Azuma Seinosuke , Kondo Yoshiyuki , Komuro Yoshiteru 
Published: November 2019

Abstract
A considerable amount of time and dedication have been devoted into the development of an unified non-dimensional random excitation forces (Power Spectrum Density) PSD model of tube bundles into two phase flow conditions. However, any model cannot be used for wide-range two phase flow conditions as random excitation forces depends strongly on a two phase flow regime. Therefore, we have developed a new scaling method for a two phase random excitation force PSD to be applicable for a wide-range of flow conditions. This method has been developed by focusing on the correlation between a two phase pressure loss and two phase turbulence energy. Comparisons of non-dimensional random excitation force PSDs in various conditions scaled by using the developed method, showed a good concordance between the two.
Finite Element Modeling of Hybrid Friction Diffusion Welding of Tube-Tubesheet Joints
Authors: Al-Badour Fadi 
Published: November 2019

Abstract
Hybrid Friction Diffusion Bonding (HFDB) is a solid-state welding process that proved its capability of producing sound tube-tubesheet joints, but with limitations on tube thickness (up to 1mm) and tube-tubesheet materials. In the petrochemical industry, there is a great demand for the use of carbon steel shell and tube heat exchangers. To investigate the feasibility of HFDB techniques in joining thicker tube (i.e 2.1 mm) on tubesheet joint, a three-dimensional thermo-mechanical finite element model (FEM) was developed and solved using ABAQUS (commercial finite element analysis (FEA) software). The model was used to predict the temperature distribution and developed stresses during and after welding. The model considered temperature dependent material properties while Johnson-cook model was used to govern material plastic flow behavior. In this paper,19 mm (¾ in) ASTM 179 cold-drawn carbon steel tube into an ASTM A516 Grade 70 tubesheet joints was simulated. Results are validated based on temperature measurements, which was found in good agreement with experimental results. The developed model can be used to optimize processing parameters (i.e. tool rotational speed, dwell time “holding time”, and forging force.. etc) and study their effect on material flow and developed stresses.
Evaluation of Creep Properties of Alloy 690 Steam Generator Tubes at High Temperature Using Tube Specimen
Authors: Kim Jongmin , Kim Woogon , Kim Minchul 
Published: November 2019

Abstract
Thermally induced steam generator (SG) tube failures caused by hot gases from a damaged reactor core can result in a containment bypass event and may lead to release of fission products to the environment. A typical severe accident scenario is a station blackout (SBO) with loss of auxiliary feedwater. Alloy 690 which has increased the Cr content has been replaced for the SG tube due to its high corrosion resistance against stress corrosion cracking (SCC). However, there is lack of research on the high temperature creep rupture and life prediction model of Alloy 690. In this study, creep test was performed to estimate the high temperature creep rupture life of Alloy 690. Based on reported creep data and creep test results of Alloy 690 in this study, creep life extrapolation was carried out using Larson-Miller Parameter (LMP), Orr-Sherby-Dorn (OSD), Manson-Haferd Parameter (MHP), and Wilshire’s approach. And a hyperbolic sine (sinh) function to determine master curves in LMP, OSD and MHP methods was used for improving the creep life estimation of Alloy 690 material.
Development of Chinese Standard on Ultrasonic Inspection for Electrofusion Joint of Polyethylene Pipe
Authors: Guo Weican , Tao Yangji , Shi Jianfeng , Miao Cunjian , Zhong Haijian , Zheng Jinyang 
Published: November 2019

Abstract
Polyethylene (PE) pipe has been widely used in the transportation natural gas, and electrofusion (EF) welding is a welding method commonly used in the welding of polyethylene pipes. Defects are likely to occur in electrofusion joints, which lead to significant casualties and economic losses if PE pipes failed during service. However, the assessment of electrofusion joints is made by visual inspection and destructive testing, which can’t detect internal defects directly. This paper introduces two recently developed Chinese standards for nondestructive testing and safety assessment of electrofusion joints. These standards illustrate inspection process, sample block, defect characterization and safety assessment. Some research, applying these standards for inspection and safety assessment of electrofusion joint, is introduced in this paper. Those researches show that ultrasonic detection technology in these standards is suitable for defects inspection, and standards provide standard technical support for the safety of polyethylene pipelines.
Integrity Mitigation Prioritization Using Multi-Criteria Decision-Making
Authors: Mehranfar Mahsa , Mejia Juan , Hassanien Sherif , Martin James 
Published: November 2019

Abstract
In-line Inspection (ILI) tools are regularly used for inspecting transmission pipelines. However, it is challenging to use such technology for a large portion of pipes; e.g. terminals and pumping stations, because of diameter changes, tight turns, or other pipe/inspection characteristics. Non-contact pipeline magnetic testing (NPMT) is a well-suited technique to inspect potentially non-ILI pipes. This paper presents a new framework for selecting and prioritizing digs-based LSM high severity features. A multi-criteria decision-making approach was developed using pair-wise comparisons which stems from the Analytical Hierarchy Process (AHP). AHP is a structured technique for organizing and analyzing complex decisions to help the decision maker set priorities and make the best decision given available information. In addition to the application of AHP, a cost benefit analysis and evaluation of risk have been conducted in order to support a risk-informed decision-making for selecting the top priority digs. Pipe properties, LSM tool reported data and Subject Matter Expert (SME) opinion were utilized in order to efficiently render a decision regarding prioritization of dig sites.
The developed approach can be used as a regular process to prioritize similar dig programs. This method is capable of ranking different dig sites based on SME opinion as well as construction information and LSM reported data.
Assessment of Structural Integrity on Irradiated Steel Structure: Focusing on Long Column Type Reactor Pressure Vessel Supports
Authors: Han Goeun , Guzey Sukru 
Published: November 2019

Abstract
The structural steel in a nuclear facility experiences significant degradation due to the accumulated neutron irradiation. Particularly, the long-column type reactor pressure vessel supports have been focused since they resist considerable loading to maintain the primary coolant system in their position and experience high neutron irradiation in low temperature, which is an unfavorable condition for the fracture toughness. This study implemented the API 579-1/ASME FFS-1, fitness-for-service (FFS) method to consider both irradiated mechanical properties and multiple loading cases. A three-dimensional (3D) finite element model of long column type reactor pressure vessel support was built for the linear analysis. The metallurgical properties of reactor pressure vessel support for assessment were estimated by empirical equations. This study provides the structural margin of long-column type reactor pressure vessel support by levels of the loads and levels of the neutron fluence.