bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Crude Oil Viscosity for Pipeline Operation Safety Using Optimized GRNN Model
Authors: Zhang Jianming , Wang Xiaolin , Shi Lei , Cui Kaiyan , Chang Liang , Sun Qianyao , Zhao Yatong 
Published: November 2023

Abstract
In the whole process of crude oil storage and transportation, the obtaining of the viscosity of crude oil timely and accurately is very important for the safe operation of crude oil pipelines. This paper proposes a new method to predict crude oil viscosity based on Generalized Recurrent Neural Network (GRNN), Particle Swarm Optimization (PSO) and K-Means Clustering Algorithm, which are different from the normal measurement in the laboratory. Feature selection, focusing on obtaining most closely related components to the viscosity of crude oil at 50 °C from the content of Kantian residual carbon, sulfur, nitrogen, water, salt, acid value, ash, colloid, asphaltene, wax, Fe, Ni, Cu and V, is introduced by using the Maximal Information Coefficient (MIC) and Sequential Floating Forward Selection (SFFS) Algorithm. The density and pour point, which are easily available, are determined as the final input of the GRNN by physical property correlation analysis to replace the most related components obtained. For most practical engineering problems that only have a small data set with partial poor samples, the K-Means Clustering Algorithm is introduced in the model to analyze the distribution characteristics of the samples and avoid the impact on the prediction results caused by poor data set. It effectively makes model evaluation more convincing. A Generalized Recurrent Neural Network (GRNN) with the parameter optimization by Particle Swarm Optimization (PSO) is constructed as prediction model. The final results show that the optimized GRNN prediction model in this paper has a good performance on prediction accuracy and stability at the viscosity of crude oil.
Modeling the Fatigue Life of Ni-Based Alloys
Authors: Falaakh Dayu Fajrul , Park Jae Phil , Bahn Chi Bum 
Published: November 2023

Abstract
In this study, we attempted to model the fatigue life of Ni alloys by employing probabilistic approaches, i.e., survival regressions. The selected models included the Weibull AFT and RSF models. The input variables for the models were the strain amplitude, strain rate, temperature, concentration of dissolved oxygen, and material category (i.e., base or weld). The dataset was divided into two subsets, i.e., training and test sets. The training set was used to train the models, while the test set was used to evaluate the models’ predictions. Several performance metrics were used to measure the model predictabilities, including the c-index, R2, and PCC. Based on performance metrics computed using test sets, all the selected models showed satisfactory performances. The RSF appeared to have better predictability than the AFT model. It was shown that the survival regression models could quantify prediction uncertainty, which is important given the limited fatigue data on Ni alloys.
Effect of Postweld Heat Treatment and Temper Bead Welding on the Hydrogen Induced Cracking Susceptibility in the Heat Affected Zone of SA-508 Pressure Vessel Steel
Authors: Mohammadi Abbas , McCracken Steven L. , Alexandrov Boian T. 
Published: November 2023

Abstract
ASME Case N-888, Similar and Dissimilar Metal Welding Using Ambient Temperature SMAW and Machine GTAW Temper Bead Technique, requires a 48-hour hold time before nondestructive examination (NDE) can be performed to ensure hydrogen induced cracking (HIC) did not occur. The objective of this work is to evaluate the effect of postweld heat treatment (PWHT) and temper bead welding (TBW) on the HIC susceptibility in the coarse-grained heat affected zone (CGHAZ) in welds of SA-508 pressure vessel steel. A previously published study used the Gleeble™ thermo-mechanical simulator to recreate six CGHAZ microstructural conditions: as-welded (AW), PWHT-ed, and single TBW reheats to 675°C, 700°C, 725°C, and 735°C. Detailed microstructural characterization of all microstructural conditions and preliminary HIC results were reported. The HIC susceptibility was evaluated using the Delayed Hydrogen Cracking Test (DHCT) at a diffusible hydrogen level significantly exceeding those introduced by the GTAW and SMAW processes. This study completed the HIC susceptibility evaluation of the six CGHAZ conditions and generated a “worst-case scenario” ranking of the TBW@700°C, TBW@725°C, and TBW@735°C as highly resistant, PHWT as resistant, TBW@675 °C as slightly susceptible, and as-welded CGHAZ as susceptible to HIC. Ongoing research is evaluating the HIC susceptibility of the six CGHAZ microstructural conditions at diffusible hydrogen levels corresponding to GTAW and SMAW processes and aiming to determine the critical hydrogen content that would cause HIC. The results from this study will be used to consider potential elimination of the NDE hold time requirement in Case N-888.
Residual Stresses Generation Process on Vessel Low Alloy Steel Cracked Plates Without Modification of the Material Properties
Authors: Louerat Jules , Doremus Luc , Ancelet Olivier , Marie Stephane , Chapuliot Stephane , Dahl Anna , Perez Gregory 
Published: November 2023

Abstract
Framatome and EDF have launched an important R&D program which aims at evaluating the effective impact of residual stresses on the fracture initiation in the brittle-to-ductile transition regime, on vessel low alloy steel plates.
The paper presented here deals with the process used for introduction the residual stresses in the selected mock up. The goal of the process is to generate residual stresses over 300 MPa in the thickness at the vicinity of the crack. The principle retained is to locally produce small inelastic compression strains, around the crack, using a thermal spot imposed in the centre of a plate on both sides. The vicinity of the defect is then quickly heated by induction so as its prevented thermal expansion induces compression stresses, which, in the case sufficiently high temperatures are reached, cause both inelastic creep and plastic strains, inducing tensile residual stressing at the end of the cooling phase.
The process has been designed by finite elements modelling based on a fine material behaviour modelling in the plastic-viscous domain. The thermal cycle has been defined to reach a residual stresses level between 300 MPa and 400 MPa up to the mid-thickness of the plate.
The experimental developments confirm the relevance of the thermal cycle defined through the numerical investigation, showing a good reproducibility, and expected residual stresses levels.
Consideration of Geometrical Effect in Fracture Mechanics Assessment for a Vessel Low Alloy Steel
Authors: Louerat Jules , Ancelet Olivier , Marie Stephane , Chapuliot Stephane , Dahl Anna 
Published: November 2023

Abstract
Numerous fracture tests have been performed by EDF and Framatome on various specimen geometries extracted from a 18MND5 ferritic steel plate, in the brittle-to-ductile transition regime. C(T), SEN(T), SEN(B), and non-standard specimens have been tested.
Based on those data, the work presented here proposes a robust identification methodology which allows the prediction of constraint effect with minor consequences of the choices of the Beremin model formulation (classical model or more complex model with a stress threshold, or a plastic strain correction) and on m parameter on the final interpretation.
Results demonstrate geometrical effects, resulting in a temperature shift of KIC distribution of most specimens to higher values than those obtained on C(T) specimens and the capability of the proposed strategy to correctly predict the experimental results.
The final goal of this work is to propose a methodology applicable in Engineering Fracture Mechanics Assessment to gain margins without considering any probability of failure or statistical approach.
Study on the Effect of Material Constraint on the Stress-Strain Behavior of Pipeline Girth Weld
Authors: Zhang Yinhui , Wang Fuxiang , Shuai Jian , Xuan Wenbo , Lei Zhengqiang , Yang Hui , Zhang Tieyao 
Published: November 2023

Abstract
For the study of the pipeline girth weld, the key to ensure the accuracy of the finite element analysis result is to obtain the accurate constitutive relationships. However, due to the complex material composition of the girth weld, it is difficult to obtain the accurate stress-strain curves. At present, the digital image correlation (DIC) testing is an important method to obtain the stress-strain curves of the girth weld. However, when this method is used for testing, there will be the material constraint effect caused by weld mismatch. The material constraint will have an important effect on the accuracy of the test result. Especially for the undermatched weld and the softened heat affected zone, the effect is more significant. This effect will make the measured stress significantly deviate from the true value and ultimately affect the accuracy of the finite element analysis result. However, there is still no sufficient study on this issue. Therefore, it is necessary to further study the effect of the material constraint on the stress-strain behavior of the weld.
In this study, the finite element analysis method is used to simulate the data processing process during the DIC test, including strain extraction and stress calculation. The girth weld is simplified to include the weld metal (WM) and the base metal (BM), that is, the properties of the heat affected zone (HAZ) and BM are the same. The effects of the geometric dimension and the mismatch degree of the weld are analyzed. The stress-strain curves inputted into the finite element model are compared with the stress-strain curves calculated based on the test method, and then the effect of the material constraint is determined. The results show that for the undermatched weld, the calculated stress based on the test method is greater than the true stress of the weld, and this difference is related to the weld size and the mismatch degree. When the weld width is large, the calculated stress is close to the true stress. With the decrease of the weld width, the calculated stress deviates from the true stress gradually. With the increase of the weld mismatch degree, the deviation of the calculated stress from the true value gradually increases. For the overmatched weld, the calculated stress is less than the true stress of the weld, but the difference is relatively small. This is due to the fact that the overmatched weld specimen will fracture in BM, and the fracture position is relatively far away from the weld, which makes the effect of the material constraint relatively small. In summary, the material constraint effect makes BM have an important effect on the deformation of the weld and changes the stress state of the weld. The results obtained in this study are important for further analyzing the weld material constraint effect and proposing a correction method for DIC test result.
Phase Shift Migration Approach Using Full Matrix Capture Optimization for Multi-Layer Ultrasonic Imaging
Authors: Cheng Jingwei , Fan Zhichao , Chen Xuedong , Xu Xiangting , Bu Yangguang , Wang Haibin , Wang Zhe 
Published: November 2023

Abstract
Ultrasonic phased array testing is a widely used nondestructive testing method seen in regular inspection of pressure vessels and pressure pipelines. However, some complex structures of multiple layers give rise to impracticality of existing imaging techniques on accurately evaluating the size and shape of defects within inner layer. In this study, a method to measure sound velocity of multi-layer structure is first established based on the full matrix capture (FMC) data, thereby automatically estimating the sound velocity of the coupling layer and ultimately optimizing the phased array focal law for the unknown multi-layered structure. The FMC-based phase shift migration (PSM) imaging method for multi-layer structures is then explored. This method processes the FMC data in the frequency-wavenumber domain and utilizes the wave motion equation layer by layer in the depth direction to realize the imaging of the target layer. In order to resolve online inspection of multi-layered structure (e.g. oil-immersion detection of tank floor), the experiments are conducted on a test specimen covered with sludge. Our finding is that the FMC-based PSM imaging method can realize the high-resolution imaging of the side drilled hole with 1mm diameter under the unknown multi-layer coupling condition. The results suggest that this method could deliver great potential to accurately locate and quantitatively evaluate small buried defects within the inner layer of complexly coupled structure and self-calibrate the fundamental imaging parameter in undiscovered coupling state.
Failure Behavior and Influencing Factors of the Sealing Structure for Type IV Hydrogen Cylinder
Authors: Tao Jiahui , Fan Zhichao , Xu Peng , Wang Lu , Ma Shuhao 
Published: November 2023

Abstract
Due to their exceptional benefits in terms of low cost, light weight, corrosion resistance, and fatigue resistance, composite overwrapped pressure cylinders with plastic liners (type IV) for high pressure hydrogen storage have attracted interest on a global scale. The sealing structure in the bottle mouth of the hydrogen cylinder is a type of material-dissimilar seal between metal and plastic, and it significantly affects the safety performance and fatigue life of Type IV cylinders. In this study, the failure behavior and mechanism of the sealing structure were investigated. The sealing performance of the bottle mouth structure was experimentally assessed by testing a type IV hydrogen cylinder with a working pressure of 70 MPa. In addition, ABAQUS was utilized to create a finite element (FE) model of the bottle mouth sealing structure, taking into account the cylinder’s deformation compatibility. On the basis of the FE model, the influence of rubber O-ring hardness, rubber O-ring thermal deformation, and the thermal sensitivity of the plastic liner’s mechanical characteristics on the structure of the bottle mouth seal was examined. These findings can contribute to the design and optimization of the sealing structure for a composite overwrapped pressure cylinder with a plastic liner for hydrogen storage.
High Temperature Performance Comparison of Spiral-Wound and Kammprofile Gaskets
Authors: Wang Lu , Fan Zhichao , Tao Jiahui , Ma Shuhao 
Published: November 2023

Abstract
Both spiral-wound and kammprofile gaskets are used extensively at high temperature applications such as refineries, petrochemical plants, power plants, etc. In recent years, the use of kammprofile gaskets have seemed to gain momentum over the conventional spiral-wound gaskets. Since the application conditions of the two types of gaskets are similar, in addition to the lack of comprehensive comparisons of two gaskets performance especially high temperature performance, it is difficult for engineers to decide which gasket to use. In this paper, mechanical properties tests at high temperature are carried out, the compression resilience curves, modulus of resilience and stress relaxation of two types of gaskets are compared. Furthermore, the high temperature sealing performance of two types of gaskets are studied by using a NPS 3, Class 300 bolted flanged joint. The mass leakage rate at different test temperatures and internal pressures are obtained.
Study on the Effect of Material Characteristic on the Limit Pressure of the Pipeline Girth Weld Containing Welding Defect
Authors: Ren Wei , Shuai Jian 
Published: November 2023

Abstract
For long-distance oil and gas pipelines, pipeline construction is actually a vast project which involves longdistance welding process. Because of technology and artificial factors, there are various types of welding defects in pipeline girth welds, such as cracks, porosity, slag inclusions, inadequate penetration, incomplete fusion and so on. Pipeline is often subject to a series of adverse conditions, including cyclic loading, pressure fluctuation, corrosion, high temperature, shock and so on, which seriously impair the performance of pipeline. Girth weld defect is one of the underlying causes, which leads to early damage to welded structure and arouses catastrophic accident. Therefore, the quality control of pipeline welds is very important to ensure the safety of pipelines. It is necessary to carry out stress analysis on the girth weld of pipeline containing welding defects to provide technical basis for the size control of pipeline weld defects. In order to study the influence of material characteristic on the limit pressure of pipeline girth weld containing porosity, based on the real structure of the girth weld, a finite element model of pipeline girth weld containing porosity was established. Stress analysis with different size of porosity was performed. And the effect of the yield strength, hardening exponent and mismatch on the limit pressure of the girth weld were analyzed. The appropriate failure criterion is selected to determine the failure of pipeline girth weld with porosity. It turned out that the local maximum Mises stress of porosity defect increases with the increase of yield strength and the strength matching factor. The local plastic area of porosity defect increases with the increase of hardening exponent. The pipeline limit pressure increases with the increase of yield strength and the strength matching factor, and the pipeline limit pressure decreases with the increase of porosity defect size under the internal pressure. The finite element results provide a reference for the tolerance size of girth weld defects, which is of great significance for making full use of the performance of pipe material and improving the quality and efficiency for pipeline safety management.
Data-Driven Stress Intensity Factor Solutions for Axial Outside Surface Cracks in Thin-Walled Cylinders
Authors: Zhu Xian-Kui , Zhu Jesse B. , Duncan Andrew J. 
Published: November 2023

Abstract
In the flaw evaluation, fracture mechanics methods require calculation of stress intensity factor, K, in fitness-for-service (FFS) codes, such as API 579 and ASME BPVC Section XI. For a surface crack in a cylinder, the K calculation becomes to compute the influence coefficients G0 and G1 in the FFS codes. API 579 provides finite element analysis-based tabular data of G0 and G1 for selected cylinder size (t/Ri), crack aspect ratio (a/c), crack depth ratio (a/t), and crack tip locations. Recently, curve-fit solutions of G0 and G1 were obtained for surface cracks at the deepest and surface points. For an arbitrary cylinder size, however, three-parameter interpolations are still needed for estimating the G0 and G1.
To simplify the K factor calculation, the present authors (PVP2022-86164) developed a data-driven K factor solution for axial outside surface cracks in thick-walled cylinders (D/t ≤ 20) based on the API 579 tabular data of G0 and G1 for axial outside semi-elliptical surface cracks at the deepest and surface points using the machine learning technology. This paper further develops a data-driven K factor solution for axial outside surface crack in thin-walled cylinders (D/t ≥ 20) using the artificial neural network (ANN). The sigmoid activation function is adopted in the optimal learning algorithm for the ANN model to learn from the API 579 tabular data of G0 and G1 and to predict the K solutions at the deepest and surface points for an arbitrary cylinder or crack size. The proposed ANN model contains three input variables, one hidden layer with five neurons, and one output variable. The data-driven solutions of G0 and G1 at the deepest and surface points of the axial outside semi-elliptical surface cracks are validated by the existing closed-form solutions for thin-walled cylinders.
A Comparative Study on AI/ML-Based Transient Temperature Predictions and Real-Time Operational Transient Temperature Data of Coke Drum
Authors: Srinivasan Balaji , V. Srinivasan 
Published: November 2023

Abstract
Uncertainties in real-time operational practice result in the deviation of actual as-operated time-varying parameters from planned operational time-varying parameters. Coke drums experience severe transient thermal-induced cyclic stresses resulting in unanticipated, low cycle, fatigue damage. The health of coke drums is of great importance as it is associated with the increased need for inspection frequencies and unwelcome shutdowns. As a result, the need for online monitoring and prediction of the integrity of components of coke drums is growing among plant operators.
In setting up an asset health integrity and monitoring system, operators must decide among timeliness, precision, and reliability. The time-varying transient temperature is the dominant parameter that has a stimulating effect on the fatigue life of coke drums. Establishing a methodology to predict the future transient temperature of typical operational sequences is of great significance to predict the health status of coke drums.
In this work, Artificial Intelligence and Machine learning (AI/ML) are used to develop a predictive model. Using the data of transient thermal temperature of a coke drum recorded during its operation, the AI/ML-based prediction model is trained. The case study of an effort to generate transient temperature predictions using AI/ML algorithms is presented in this paper. The results obtained from this model are compared to the realtime as-operated transient temperature data set. Further, this AI/ML-based predictive model is planned to be used in a Digital Twin for preventive maintenance of coke drums.
Evaluation of Crack Initiation Probability by FERMAT Code in Conformity With the Procedure by a Japanese Industrial PFM Guideline
Authors: Miyashiro Satoshi , Sakai Takayuki , Nagai Masaki , Yamamoto Masato 
Published: November 2023

Abstract
The implementation of probabilistic fracture mechanics (PFM) on integrity assessment standards of reactor pressure vessels (RPVs) is not yet actualized in Japan. The most recent information on how PFM will be used in the near future is provided by the guideline JEAG 4640-2018, which describes a standard approach for evaluating the failure frequency of RPVs based on PFM. Central Research Institute of Electric Power Industry is creating a new PFM analysis code FERMAT (Fracture mechanics Evaluation of RPV MATerials) for future application of PFM in Japan. Our code is based on JEAG 4640-2018 and has a minimum design for practical usage in RPV structural integrity assessments. With a graphical user interface, all processes can be handled in a single piece of code. In the present study, calculation results by FERMAT were compared with another Japanese PFM code PASCAL4 with a model case targeting Japanese RPV. The distribution of temperature and stress evaluated by FERMAT and PASCAL4 were very similar. The stress intensity factor calculated by FERMAT and PASCAL4 was well corresponding with each other. Additionally, sampled values for reference temperature for nil-ductile transition were confirmed. The probability and the frequency of crack initiation were compared between FERMAT and PASCAL4. The outcomes assessed using those codes were closely related to one another.