bluuebunny/crossref_metadata_2025_split huggingface dataset:
INCEFA-SCALE Project – Data Mining and Lessons Learning
Authors: Cicero Roman , McLennan Alec , Mann Jonathan , Beswick Jack , Doremus Luc , Cuvilliez Sam 
Published: November 2023

Abstract
INCEFA-SCALE is a five-year project supported by the European Commission HORIZON2020 program. It is the successor to the INCEFA-PLUS project that ran from 2015 to 2020. Both projects try to address existing gaps between the fatigue behavior of stainless steels in the laboratory, real fatigue behavior observed in nuclear components during operating service, and provide guidance on how to account for the studied behavior in fatigue assessments.
These programmes are contributing to a database with a large number of parameters (strain amplitude, strain rate, temperature, surface roughness, hold time periods, chemistry, etc.). Once the International Fatigue Database Agreement is signed, this database will be augmented with fatigue data shared by international organisations from the US, Korea, Japan and Europe. This will enable INCEFA-SCALE to investigate one of the largest fatigue databases in the world. However, a database compiled from a range of sources with differing objectives creates an issue for analyists as the data will not necessarily be balanced. The impact that this issue may have on an analysis can be mititgated through good data screening and selection practice that must be informed by data visualization. One of the objectives of the INCEFA-SCALE data mining workpackage is to develop and provide a set of tools to aid in this mitigation as well as enabling the statistical analysis of the broader dataset.
During the INCEFA-SCALE project, a data mining tool was developed to statistically analyze all data available to date. In this paper, these tools are presented and, as a proof of concept, used to analyse the available using similar concepts to that of INCEFA-PLUS. To aid in the evaluation of the database and tools expressions for predicting fatigue life of stainless steel specimens in air and ligh water reactor primary coolant conditions are provided. A key requirement of these data exploration and analysis tools is that they are generally accessible and available to the INCEFA-SCALE community to support collaborative data analysis. The conclusions and findings extracted from this data mining analysis are shown and compared with the current procedures most used in environmental fatigue analyses of nuclear components and systems.
Study on the Calculation Method of Fluid Distributor of Corner-Corner Type in Heat Exchangers
Authors: Zhu Guodong , Song Libin , Zhang Yanfeng , Xie Tian 
Published: November 2023

Abstract
The fluid distributors of corner-corner type (named in ASME, FDCC in abbreviation in this paper) are more and more frequently adopted in large high effective condenser or large efficient heat exchanger because of its advantages of space saving, easy to manufacture and high steam flux. But, high local stresses due to discontinuity at its right angle connection would lead to fracture failure or uneconomical design with current empirical rough design method. Meanwhile, the fluid distributor as the pressure element in shell side of heat exchanger, its axial stiffness would affect the tubesheets, shell and tube bundle of the fixed-tubesheet heat exchanger based on the mechanical model and theory in ASME code. Unfortunately, there is no accurate, scientific solution so far because of its complex structure.
In this paper, the structure character and loads of the fluid distributor were introduced and its risk in design was analyzed. An accurate analytical solution based on elastic shell and plate theory was put forward for the fluid distributor under inner pressure and/or axial forces. The detailed calculation method with linear equation matrix was presented to solve the overall strength, local stresses, and stress trend curves for each component and its overall axial stiffness for the fluid distributor. Finally, the method was verified by numerical simulation. The results indicate that the method developed in this paper is valid and accurate to resolve the current design problems. Meanwhile, it is shown by an example that the method can be programed for effective design for fixed tubesheet heat exchangers.
Results of the Explosive Destruction System P3 Vessel Qualification
Authors: Tribble Megan , Stofleth Jerome , Crocker Robert , Ludwigsen John 
Published: November 2023

Abstract
The V31 containment vessel was procured by the US Army Recovered Chemical Material Directorate (RCMD) as a third-generation EDS containment vessel. It is the fifth EDS vessel to be fabricated under Code Case 2564 of the 2019 ASME Boiler and Pressure Vessel Code, which provides rules for the design of impulsively loaded vessels. The explosive rating for the vessel, based on the code case, is 24 lb (11 kg) TNT-equivalent for up to 1092 detonations. This report documents the results of explosive tests that were performed on the vessel at Sandia National Laboratories in Albuquerque, New Mexico to qualify the vessel for field operations use. There were three design basis configurations for qualification testing. Qualification test (1) consisted of a simulated M55 rocket motor and warhead assembly of 24 lb (11 kg) of Composition C-4 (30 lb [14 kg] TNT equivalent). This test was considered the maximum load case, based on modeling and simulation methods performed by Sandia prior to the vessel design phase. Qualification test (2) consisted of a regular, right circular cylinder, unitary charge, located central to the vessel interior of 19.2 lb (8.72 kg) of Composition C-4 (24 lb [11 kg] TNT equivalent). Qualification test (3) consisted of a 12-pack of regular, right circular cylinders of 2 lb (908 g) each, distributed evenly inside the vessel (totaling 19.2 lb [8.72 kg] of C-4, or 24 lb [11 kg] TNT equivalent). All vessel acceptance criteria were met.
Crack Size Measurements on Fracture Surface Images Using Deep Neural Networks for Semantic Segmentation
Authors: Rosenberger Johannes , Tlatlik Johannes , Münstermann Sebastian 
Published: November 2023

Abstract
For the safe evaluation of nuclear-relevant safety components, a precise and reliable analysis of the fracture surfaces after the test procedure is required. Within the scope of the studies a framework for automated crack size measurements based on image segmentation has been developed, capable of accelerating the standardized but tedious measurement procedure. Different known image segmentation architectures have been trained and assessed based on a specially created fracture surface image dataset. The fracture surfaces originate from SE(B) specimens made of the German reactor pressure vessel steel 22NiMoCr3-7 and its weld material. The evaluation of the model performances via the mIoU metric show that the investigated architectures are very well suited for the pixel-fine classification of fracture mechanisms. Based on the obtained prediction masks, the initial crack size a0 could be measured using the so-called area average (AA) method. The results have been compared to manual 5-point average (5PA) measurements. The automated crack length measurements show statistically verifiable very high precision, comparability, and economic efficiency.
CMOD Compliance Solution Determined by Stress Intensity Factor for Single Edge Notched Tension Specimens in End-Clamped Conditions
Authors: Zhu Xian-Kui 
Published: November 2023

Abstract
The oil and gas industry favors to use single edge notched tension (SENT) specimens in the end-clamped conditions to measure less conservative fracture toughness or resistance curves in low constraint conditions. Usually, single specimen test approach is adopted to measure J-integral or crack tip opening displacement (CTOD) based-resistance curves (simply J-R curves or CTOD-R curves), where the elastic unloading compliance technique is often utilized to monitor crack growth in the quasi-static conditions, and instantaneous crack length is inferred from crack mouth opening displacement (CMOD) compliance measured at each loading step during a single specimen test. Several numerical solutions of CMOD compliance were obtained by finite element analysis for end-clamped SENT specimens. However, these CMOD compliance solutions have varied accuracies and different applicable ranges of crack length ratio a/W. Some of them may be inconsistent with existing solutions of stress intensity factor K for the same clamped SENT specimen because the K factor and the CMOD compliance were determined separately by FEA calculations. Due to this reason, the present paper obtains a more accurate analytical solution of CMOD compliance equation from an accurate full-range K solution for the end-clamped SENT specimens, and thus the proposed analytical solution of CMOD compliance is consistent with the stress intensity factor. Comparisons with different FEA results confirm a higher accuracy of the proposed CMOD compliance solution. Finally, an improved SENT test method is discussed for determining JR and CTOD-R curves.
Material Deterioration and Residual Life Evaluation of High Temperature Steam Pipeline
Authors: Li Zhifeng , Song Libin , Chen Gang 
Published: November 2023

Abstract
Cracks were found in high temperature steam pipes which had been used for 100 000 hours. The mechanical properties of pipe material were tested, and the causes of cracks were analyzed by metallographic and scanning electron microscopy. The fracture parts of the tensile specimens were all in the weld fusion line. The metallographic photos of the weld section showed that there were a large number of precipitates on the fusion line. The energy spectrum analysis showed that the main alloying elements of the precipitates were chromium and molybdenum. The location of a large number of precipitates was consistent with the location of surface cracks. Combined with the working parameters of the pipeline, it was judged that the crack was a creep crack. The existence of precipitates led to micro-local stress concentration and provided conditions for the initiation of cracks, resulting in the weld fusion line becoming the primary part of the creep crack. The stress rupture test showed that the fracture time of the weld sample was shorter under larger load. The residual life of the pipeline was analyzed by using the mechanical properties obtained from the test. The conservative calculation results showed that the residual life of some stress concentration parts was 139.68 hours.
A Phase Field Approach to Fracture Mechanics Problems
Authors: P. C. Sidharth , Rao B. N. 
Published: November 2023

Abstract
Phase field modeling of fracture is a widely used numerical method for predicting fracture-related phenomena in solids. The phase field method is a continuous or diffused approach to fracture that approximates the original crack into a diffused zone of fracture. The diffused region is represented by an auxiliary variable called the phase field, which takes values between one and zero for broken and unbroken phases, respectively. The method is becoming increasingly popular since it conveniently solves the difficulty of explicitly tracing the cracks as displacement jumps and incorporating the same in the finite element mesh. The method gives accurate results for finite element meshes that are sufficiently refined. Exponential finite element shape functions offer a way of enhancing the computational efficiency of simulations. These special shape functions, due to their exponential nature, can capture sharp changes in solution variables with a lesser number of elements employed along the crack propagation path. However, exponential finite element shape functions need to be oriented with respect to the crack propagation path in order to provide a good approximation. This study presents an efficient implementation. An efficient implementation of the phase field fracture model is presented by employing automatically oriented exponential finite element shape functions. The orientation of these shape functions is informed by an approximate analysis using bilinear shape functions. The implementation is validated with previous simulations available in the literature. Computational costs and the accuracy of solutions are investigated for a few common fracture problems.
Technical Basis for Revision to Code Case N-702
Authors: Walter Matthew , Wong Kevin , Cofie Nathaniel G. , Uddin Mo , Dominguez Gary 
Published: November 2023

Abstract
Boiling water reactor (BWR) reactor pressure vessel nozzle-to-shell welds and nozzle blend radii are inspected in accordance with ASME Code, Section XI, which requires 100% inspection during each 10-year in-service inspection interval. ASME Code Case N-702-1 provides inspection relief to 25% of the nozzle population every 10 years. The NRC placed limitations on N-702-1 which excluded feedwater nozzles and control rod drive return nozzles and only allowed implementation for up to 40 years of plant operation. N-702-1 has been used by many utilities for inspection relief, resulting in substantial time, dose and cost savings related to inspections. N-702 was incorporated into ASME Code, Section XI, IWB-2500, Item f in 2018.
Since many plants are operating beyond 40 years, and some plants intend to operate as long as 80 years, there is a need to extend the applicability for up to 80 years of operation. Furthermore, it is desirable to include feedwater nozzles in the technical basis. This paper provides the technical basis to update Code Case N-702 to be applicable for up to 80 years and includes feedwater nozzles. Other updates are also made to the evaluations to bring the analysis in-line with current industry standards.
A summary of the probabilistic fracture mechanics inputs and results are provided in this paper, which demonstrates the probability of failure is within NRC-approved acceptance criteria for each case analyzed. Several sensitivity studies were also performed in order to evaluate the impact of different inputs. Screening criteria is provided for each RPV nozzle including relevant operating parameters. This paper is intended to provide the technical basis for a revision to Code Case N-702-1.
Analysis of Spiral Wound Gasket Behavior Against Tightening With Face Rotation
Authors: Kataoka Shunji , Sato Suguru , Takahashi Kyohei 
Published: November 2023

Abstract
In recent years, leakage reduction and assessment have become necessary from an environmental protection perspective. It is important to properly calculate the gasket contact pressure to estimate and reduce leakage in the design stage.
ASME PCC-1 and API 660 demand higher gasket stress to prevent leakage in service. Increasing the bolt tightening load is expected to improve the gasket sealing performance while flange face rotation increase. Flange face rotation causes the unbalance in gasket contact pressure distribution: while the maximum contact pressure increases, the area of high contact pressure decreases. It is difficult to evaluate the unbalance in gasket contact pressure distribution experimentally. Therefore, a detailed analysis is essential to assess how this affects the sealing performance. SWG is widely used in oil and gas industry. However, the detailed analysis has been difficult due to the spiral structure and the composite property of constituent materials.
In this paper, firstly, the method for detailed analysis of SWG was proposed. The analysis model was developed by combining a hyper-foam material model of CEG filler with a detailed SWG geometry model. Secondly, the analysis model was validated by uniform compression test by parallel plate. The gasket stress curve simulated by the developed model was well matched in the result of uniform compression test. Finally, the effect of flange face rotation to the compression behavior was studied by the developed model. Based on the contact pressure distribution and the filler compression distribution, the relationship between the overall compression behavior and the interaction of constituent materials was discussed.
Study on Regular Inspection Standard of Large Volume Carbon Fiber Fully Wound Cylinder Bundles
Authors: Fang Zhou , Liu Qia , Wang Zhe 
Published: November 2023

Abstract
The large-capacity storage cylinder set in long tube trailers is a key element for transporting high-pressure gas, and its safety in use is of concern. Among them, carbon fiber wound plastic liner is a new generation of gas cylinders with the advantages of lightweight and corrosion prevention. At present, the United States, the United Kingdom and the International Organization for Standardization have established standards on the periodic inspection of carbon fiber fully wound gas cylinders. This paper introduces the scope of application, the content of periodic inspection, and evaluation of the results of these standards based on the comparative study of Chinese TSG 23 Technical Regulations for Gas Cylinder Safety. The group standard T/GDASE 0017-2020 “Periodic Inspection and Evaluation of Carbon Fiber Fully Wound Gas Cylinders with Aluminum Lining for Automotive Compressed Hydrogen Gas” issued by Guangdong Special Equipment Industry Association and the International Organization for Standardization IS011623. And an assessment of the results of these standards and other aspects of the different requirements. On this basis, this paper points out the shortcomings of the testing methods used in the periodic inspection of large volume carbon fiber wound gas cylinders with long tube trailers in China, taking into account the demand for hydrogen storage and transportation in China and the current situation of cylinder production technology in enterprises. Finally, this paper provides some suggestions for the development of a new generation of cylinder periodic inspection and assessment standards and points out several issues that need to be studied in focus for future standard development and implementation for reference.
Study on Analysis Procedure Using Integrated Three-Dimensional FE Model for Reactor Coolant System by Applying to Shaking Table Tests for Scaled Mock-Ups
Authors: Kawashima Takehiro , Kumagai Yasutaka , Asao Yuki , Shimazu Shota , Nishimura Takuya 
Published: November 2023

Abstract
Generally, seismic stress evaluation for a Class 1 component of a nuclear power plant is performed using Finite Element stress analysis with seismic loads that are obtained another calculation. In Japan, a multimass beam model is usually employed to calculate seismic loads for components in a reactor coolant system (RCS) of PWR plant. The components are modeled into simple elements such as mass points and beams in the multimass beam model. So far, three-dimensional FE analysis (3D-FEA) has been applied to stress analysis for each portion in a component. Recent advances in computer performance, however, have made large-scale analysis possible, and 3D-FEA for not only whole of a component but also the integrated all components in a RCS is not difficult at the present time. If the integrated whole 3D-FE model of RCS is employed, stress due to seismic can be directly calculated by applying seismic waves to the 3D-FE model, and the multimass beam model is not necessary. So, we are developing a stress evaluation method that uses an integrated 3D-FE model consisted of all components in RCS, which is called “Seamless Structural Analysis Process”. As a validation for this method, this method has been applied to the shaking table tests for scaled mock-ups previously conducted by the Japanese national projects and the results are discussed in this paper. Three scaled mock-ups, which were modeled for reactor coolant system (RCS), reactor vessel (RV) and reactor vessel internals/control rod drive mechanism (RVI/CRDM), were prepared for these projects. In our study, 3D-FE models have been developed for the RCS, RV and RVI/CRDM mock-ups, and time history response analyses have been performed for those 3D-FE models. The results are discussed in this paper.
Prediction of Dormancy Time of Cryo-Compressed Hydrogen Tank by Considering Dynamic Thermal Boundary
Authors: Yuan Yutong , Ge Zhoutian , Shi Jianfeng 
Published: November 2023

Abstract
Hydrogen has advantages of high efficiency and cleanliness, which has become main target of energy strategy development in many countries. Hydrogen storage is an integral part of the efficient utilization of hydrogen energy, and high pressure and low temperature can effectively improve the storing energy density. This paper studied the hydrogen storage behavior of cryo-compressed hydrogen (CcH2) in an insulated pressure tank. Since the temperature of CcH2 can change from 40.15 K to 233.15 K, it is crucial to consider the temperature change when predicting the dormancy time of CcH2 tank. This paper proposed a theoretical method for predicting the storage behavior of cryo-compressed hydrogen storage tank. The heat influx of radiation, conduction and convention through the thermal boundary of CcH2 tank was calculated based on realtime temperature difference between liner and outer vessel. The theoretical method was verified by experimental results from existing reports, and the predicting results showed good consistency. Furthermore, based on the dynamic heat influx, the influence of filling rate, initial pressure and initial temperature on dormancy time was discussed in detail. Finally, a prediction model was proposed for estimating the dormancy time for cryo-compressed hydrogen.
Numerical Analysis of Gas Explosion Characteristics of Gas Compartment of Utility Tunnel Based on FLACS
Authors: Ma Honglian , Huang Hui , Zhang Guiyuan , Chen Zhiwei , Ji Fang 
Published: November 2023

Abstract
With the rapid development of urbanization and the comprehensive demand for the utilization of urban underground space resources, Utility tunnel, as an emerging infrastructure of the advanced laying method of municipal public pipelines, it’s safe operation is related to the safe operation and functional guarantee of the city, and it is a major “lifeline” project of the city. As one of the most dangerous sources, gas pipeline is prone to secondary and derivative disasters in case of leakage, explosion and other disastrous accidents, which brings great challenges to the safety of urban underground utility tunnel. Based on FLACS simulation, this paper studies the gas explosion characteristics of the gas compartment of utility tunnel. The results show that the explosion overpressure reaches the peak when the methane volume fraction is 9.41%; Compared with the closed pipe gallery model, the preset vent of the comprehensive pipe gallery has a strong pressure relief effect. This research can not only provide basic data for the dynamic response of the explosion impact load to the pipe gallery structure, but also provide theoretical and technical support for improving the disaster prevention and mitigation capability of the gas compartment of utility tunnel, which is of great significance for improving the sustainable and safe development of the city.