bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Probabilistic Analysis Code for Evaluating Seismic Fragility of Aged Pipes With Wall-Thinning
Authors: Yamaguchi Yoshihito , Nishida Akemi , Li Yinsheng 
Published: November 2022

Abstract
The wall-thinning is one of the most important age-related degradation phenomena in nuclear piping, because several accidents of wall-thinned pipe failures have occurred. Furthermore, in recent years, several plants in Japan have experienced severe earthquakes. Therefore, failure probability analysis and fragility evaluation of piping systems, taking both wall-thinning and seismic response stresses into consideration, have become increasingly important in seismic probabilistic risk assessment.
In Japan Atomic Energy Agency, in order to evaluate the failure probability of aged pipes with wall-thinning, a probabilistic analysis code PASCAL-EC (Probabilistic Analysis of Structural Components in Aging LWR – considering Erosion Corrosion) has been developed. In this study, to evaluate the seismic fragility of a wall-thinned pipe, a model of seismic response stress considering the wall-thinning effect, a failure evaluation method for wall-thinned pipes, and functions related to uncertainties treatment have been introduced to PASCAL-EC. In this paper, the improved PASCAL-EC is outlined and preliminary results of the seismic fragility evaluation performed using this code are provided.
A Statistical Study of Mechanical Properties From Mild Steel Welds Deposited via Gas Metal Arc Additive Manufacturing (GMAAM)
Authors: Schaeffer J. Ben , Barnhart Brad , Melfi Teresa 
Published: November 2022

Abstract
Welding has been used for decades to create materials from weld metal that were machined to form components and used as a substitute for long lead-time castings, plate and forgings. Past terms like “shapewelding” or “shape melting” have been replaced with “additive manufacturing” to describe the process, but there is debate whether it should be treated as an additive/subtractive manufacturing process or a welding process followed by machining.
Welding procedure qualifications verify weld metal properties. The properties of qualified welds are quite predictable when the welding parameters (variables) are controlled. The range of variables to be controlled and the allowable limits vary based on the risk tolerance of the application. These variable qualification limits are covered in various welding qualification codes and standards.
In the past, code rules for weld metal buildup were used to qualify additive weld metal, but tighter controls are demanded today. Because of this, ASME Section IX developed and published rules in Code Case 3020 [1] for welding procedure qualifications that are specific to gas metal arc additive manufacturing (GMAAM).
The Code Case 3020 qualification rules require testing weld metal properties at the highest and lowest cooling rates to be used in production. Code Case 3020 rules also require testing the thinnest wall section and a thick section for each of those cooling rates. The rules also require that all of the essential and supplementary essential variables used for weld metal joining and operator qualification in ASME Section IX continue to be followed.
An ASME supported research project was launched to validate these rules. The project included a design of experiments (DOE), created by subject matter experts and vetted by an advisory committee consisting of designers, fabricators, consultants and metallurgists. Approximately two tons of weld metal was deposited using 24 different sets of welding parameter input configurations as set out by the DOE. Over 300 tensile specimens and over 500 Charpy V-notch (CVN) specimens were taken from various orientations and tested to characterize the weld metal properties. The data was analyzed to determine if the variables and interactions provided statistically significant prediction of the weld metal properties. The degree of isotropy and the extent to which manipulated variables predict weld metal properties are key findings. This paper examines those results, and discusses the relationships as they relate to new and existing code rules.
Reliability Improvement Concept on Welded Lip-Seal Heat Exchanger Flange Joints
Authors: Yuen Simon , Fernando John , Penso Jorge , Kwok Henry , Serate Duane 
Published: November 2022

Abstract
Lip-seal flange joints are commonly used in high-pressure heat exchanger design when there exists a significant temperature differential along the circumference of the heat exchanger flanges. This type of joint consists of two metal ring gaskets that are welded together to provide the necessary pressure seal. While conventional metal ring gaskets generally provide sufficient structural reliability, cracks have been reported to develop on the joints unexpectedly. This study investigates several special joint design features that aim to improve the reliability of such joints. Specifically, these features include machined pockets in the flange faces and weld overlay to house/constrain the lip-seal components, a self-alignment lip-seal feature, and tight fabrication tolerances. These improvement features mitigate thermal stresses on the lip-seal joints, thereby increasing the fatigue life of the joints. In addition, the self-alignment feature has the potential to aid in the optimization of field installation procedures. In the current work, the proposed improvement features are assessed using a series of FEA simulations to demonstrate their effectiveness. In particular, stress distributions at critical locations of the joint are compared between the new design and the conventional lip-seal design to quantify the relative improvement of the proposed design changes.
Numerical Study on Buckling Behaviors of Thin-Walled Longitudinal Corrugated Cylindrical Shells Under Axial Compression Loads
Authors: Ma He , Chen Zhiping , Jiao Peng , Lin Xinyi 
Published: November 2022

Abstract
Thin-walled cylindrical shell structures are widely used in various engineering fields due to their highly efficient load carrying capacity. This kind of structures is prone to buckling failure when subjected to axial compression loads. Machining the shell into corrugated shape is an effective method to prevent buckling. Rational design of corrugated shells can improve the load carrying efficiency of shell structures. However, there are few studies focused on the effects of various parameters on the longitudinal corrugated cylindrical shell buckling. In this paper, numerical studies are performed to analyze the factors affecting the buckling behaviors of thin-walled longitudinal corrugated cylindrical shells under axial compression loads. The cross section of the corrugated shell is obtained by superposing the sine curve on the reference circle. The critical buckling load, buckling mode and imperfection sensitivity of the longitudinal corrugated cylindrical shells are examined and compared with ordinary cylindrical shells. The effects of shell dimensions and material yield strength are taken into account. In addition, the influence of cross section shape parameters on the critical buckling load is considered, including the amplitude A and wave number k. Results show that the axial load carrying capacity of longitudinal corrugated cylindrical shells is better than ordinary cylindrical shells, and rational design of cross section shape can enhance the stability of corrugated shells. This work can provide some reference for relevant experimental studies. Furthermore, it can also give some guides for the application of thin-walled longitudinal corrugated cylindrical shells in actual engineering.
Experimental Study on Flow-Induced Vibration Control of Multiple Cylinders in Tandem With Helical Strakes
Authors: Tang Bowen , Fan Xiantao , Tan Wei 
Published: November 2022

Abstract
Flow-induced vibration (FIV) is a significant phenomenon that often occurs in actual situations, such as chemical towers, stacks, risers and offshore structures. Taking effective artificial measurements to control FIV is crucial to achieve the safe and long-period operation of engineering structures. Many researchers have verified that helical strakes can efficiently disturb the Karman vortex streets and suppress the vortex-induced vibration of isolated structures. The effect of helical strakes on controlling the FIV of gathered structures still needs to be investigated due to the complex vortex-structure interactions. A system of multiple cylinders with elastic support is an idealized representative to model the gathered engineering structures, which was used in the present work. The dynamic responses of three tandem cylinders (m*ξ = 0.09) with helical strakes under different spaces were experimentally tested in a wind tunnel. All cylinders were allowed to vibrate in the cross-flow direction. The experimental wind speed range was 0.5∼11 m/s, and the cross-section shapes of the helical strakes were designed to be square, involute and D-shaped. The vibration responses of the cylinders after installing helical strakes were analysed through comparison with those of the plain tandem cylinders. It is concluded that the D-shaped helical strake can decrease the FIV responses of tandem cylinders by 56.8% due to the reduction in the lift coefficients of the cylinders. Furthermore, the optimal parameters of the D-shaped helical strake for the tandem cylinders under different spaces were obtained, which can provide a theoretical basis for the FIV control of gathered engineering structures.
Design of an Intelligent Butt-Fusing Welding Machine for HDPE Pipes
Authors: Wang Zhenchao , Xu Lu , You Qijiang , Peng Yijuan , Zhang Qiuju 
Published: November 2022

Abstract
Reliability of the Butt-Fusing Welding (BFW) joint of High-Density Polyethylene (HDPE) pipes is highly affected by the given parameters of Fusion Procedure Specification (FPS). Due to the operational effect, machine process capability and the impact of environment & climate, the required FPS may not be accurately applied to the joint and may vary largely during the welding process. The methods to assess the mechanical property and life expectation of the welding joint are very complicated. The best performance of welding joint is guaranteed by a capable machine which can execute an approved FPS correctly. The machine innovated and presented here is highly automatic and intelligent. It eliminates operational mistakes and delivers the consistence for joint quality. This machine reacts to the environmental influence, and thus, eliminates or compensates their effect. With the creative calibration system, it can self-detect the faults of those critical parameters. Therefore, welding process reliability is reached. Melted material geometry is used as the criteria to judge the quality of joint, which is a method of non-destructive inspection. In addition, this machine is reliable to be used to assess and define a best FPS to improve joint quality.
Difference of Hydrogen Diffusion Regularity Between Interstice-Doped and Substitution-Doped Formed by Steel Carburizing
Authors: Xing Baihui , Wang Jing , Wei Haotian , Shang Juan , Hua Zhengli , Gu Chaohua , Zheng Jinyang 
Published: November 2022

Abstract
Carburizing treatment can improve the carbon content of the workpiece material, and obtain higher contact fatigue strength, bending fatigue strength, as well as higher surface hardness. After carburizing, the existence of carbon atoms can hinder the adsorption and diffusion of hydrogen, thus reducing the hydrogen embrittlement. First-principles plane wave calculations based on spin-polarized density-functional theory (DFT) and the generalized gradient approximation (GGA) have been used to study the adsorption and permeation of hydrogen on iron in the bulk with carbon interstice solid solution and carbon substitution solid solution. Considering that hydrogen diffusion is faster in martensitic tissue, bcc-Fe structure is selected for the model. The results show that the hydrogen diffusion rate Di in the interstice solid solution is higher than Ds in the substitution solid solution. The formation of substitution solid solution is promoted by more vacancies in the lattice. When the vacancy is occupied by carbon atoms, the hydrogen diffusion rate is reduced. This phenomenon is more obvious for Fe48C16 structure with higher carbon ratio. Besides, charge density diagram and state density analysis are also consistent with this conclusion. Therefore, during carburizing, Increasing the content of carbon and carbon substituted solid solution can reduce the penetration of hydrogen in the material.
Study on Burst Pressure of Type Ⅳ Hydrogen Storage Cylinder Based on Progressive Failure Analysis
Authors: Zhu Ning , Ma Kai , Gu Chaohua , Zhang Ruiming , Hua Zhengli , Wei Liqing 
Published: November 2022

Abstract
Hydrogen has attracted worldwide attention due to its renewable and pollution-free advantages. Hydrogen fuel cell vehicles have become an important direction for the development of the automotive industry. Carbon fiber reinforced composite hydrogen storage cylinder with plastic liner (Type IV hydrogen storage cylinder) is the main research direction of vehicle hydrogen storage because of its lightweight and excellent resistance to fatigue and corrosion. However, its safety still receives much concern. In this paper, the burst pressure prediction model of type IV hydrogen storage cylinder was established by the user subroutine UMAT of finite element calculation software ABAQUS based on the Hashin failure criterion and the damage evolution law of carbon fiber composite. The damage evolution behavior of carbon fiber winding layer of the cylinder in the process of loading was analyzed. In addition, the influence of winding thickness, winding sequence and winding angle on the burst pressure was obtained.
The Mechanical Performance of Additively Manufactured 316L Austenitic Stainless Steel
Authors: Wisbey Andrew , Coon David , Chatterton Mark , Barras Josh , Guo Da , Yan Kun , Callaghan Mark , Mirihanage Wajira 
Published: November 2022

Abstract
Additive manufacturing (AM) offers the potential for significantly reducing the time and cost of new nuclear components. This process may also permit unique design features, for example internal geometries. However, the limitations of the technology need to be better understood to enable implementation and accreditation.
Here a “blown powder” and laser melting process, within a helium shielded environment, was used to fabricate austenitic stainless steel 316L walls of ∼2.4 mm thickness, with the deposition parameters minimizing the surface roughness.
A key aim was to evaluate the effect of the as-deposited surface finish and the bulk material on the tensile and fatigue properties. In addition, the effect of material orientation was also considered to be important.
Microstructural characterization demonstrated the complex nature of the grain morphology arising from the as-manufactured AM process, including elongated grains following the thermal gradients. However, areas of equiaxed grains were also observed at the sample surfaces. Si-Mn-O particles, up to ∼20 μm in diameter, were noted throughout the samples produced. Residual strains have also been measured and correlated with microstructural features.
The tensile performance was generally similar to wrought 316L material but exhibited some anisotropy. The fatigue endurance of as-deposited AM 316L was significantly lower than wrought material. However, surface grinding of the AM 316L was shown to be beneficial. It was noted that in all cases examined, fatigue crack initiation was found to occur at the Si-Mn-O particles, in both surface finishes — clearly a performance limitation.
An Elastic Buckling Pressure Level Comparison for Torispherical Heads - Empirical Equations vs. FEA Results
Authors: Belloni Mark , Shah Pankajkumar K 
Published: November 2022

Abstract
Torispherical heads are known to exhibit buckling due to internal pressure for a variety of vessel configurations. This paper provides an overview of the phenomenon and includes Finite Element Analysis results to confirm the elastic buckling pressure threshold for a set of torispherical head shapes. Internal elastic buckling pressure levels from the ASME Section VIII, Division 2 threshold pressure for buckling and from the FEA results are compared. These results are applicable for the design of the ASME Section III – Class 1 torispherical heads based on Article A-4000 of ASME Section III.
Plots of buckled shapes and corresponding hoop stresses are presented. The vessel geometry diameters studied range from 84 in., to 120 in., to 144 in.. The crown radius to knuckle radius (L/r) ratios included in the study range from 6 to 14. Design pressures used to size the vessel wall range from 100 psi to 1300 psi in non-uniform increments. The data sets generated in the study are discussed. Nonlinear geometric effects are not considered in the buckling pressure level results generation.
Failure Bending Stresses for Small Diameter Thick-Wall Pipes
Authors: Yamaguchi Yoshihito , Hasegawa Kunio , Li Yinsheng , Lacroix Valery 
Published: November 2022

Abstract
Four-point bending tests without internal pressure were performed for Type 304 stainless steel pipes with circumferential flaws at room temperature. The specimens are 1-inch diameter (33.7 mm) Schedule 160 pipes (6.3 mm wall thickness). The flaws were part-through flaws located at the pipe external side. The flaw angles are from 120° to 240°, and the flaw depths are two cases of 50% and 75% of the wall thickness. Plastic collapse stresses obtained from experiments were compared with those calculated using Limit Load Criteria from Appendix C of the American Society of Mechanical Engineers Code Section XI. Limit Load Criteria were developed using flow stress at flawed section of the pipe. The plastic collapse stress test results were larger than those of the calculation results. For flaws with flaw depths less than 50% of the wall thickness, the experimental stresses were significantly large. The Limit Load Criteria given by Section XI provide conservative collapse stresses and could be improved.
Development of the Buckling Evaluation Method for Large Scale Vessel in Fast Reactors by the Testing of Austenitic Stainless Steel Vessel With Severe Initial Imperfection Subjected to Horizontal and Vertical Loading
Authors: Okafuji Takashi , Miura Kazuhiro , Sago Hiromi , Murakami Hisatomo , Ando Masanori , Okajima Satoshi 
Published: November 2022

Abstract
The current buckling design code of Class 1 vessels for fast reactors (FRs) power plant in Japan, “Design and Construction for Nuclear Power Plants, Division 2 Fast Reactors” by the Japan Society of Mechanical Engineers, focuses primarily on plastic buckling of austenitic steel vessel. For next-generation FRs, the higher-yield material, especially ASME Grade 91 steel, plans to be applied to the vessels such as steam generators in addition to austenitic steel. Seismic isolation system is also being devised in the next plant to meet the design seismic load in Japan.
To accommodate these conditions, the standard buckling strength equations were proposed in the previous study, which were modified by considering elasto-plastic buckling of vessel. The modified equations consisted of elasto-plastic axial compression, bending, shear buckling, and their interactions, as well as ASME/BPVC CASE N-284, considering the reduction of buckling strength by cyclic larger vertical load with long-period lower horizontal load under the horizontal seismic isolation plant design. The applicability of the modified buckling equations to high-yield material was confirmed by a series of buckling tests to vessels of Grade 91 steel under cyclic loading considering horizontal seismic isolation, or with the circumferential wrinkle shape corresponding to elephant’s foot buckling (EFB) mode in the previous study.
In this study, the applicability of the proposed modified buckling equations has been confirmed through the test of austenitic steel, which has lower yield stress than Grade 91 steel, with imperfections under the load condition corresponding to seismic isolation design. The experimental result has confirmed the conservativeness of the modified equations under the dominant axial compressive load accompanied with horizontal load, and the austenitic steel vessel which has the circumferential wrinkle shape corresponding to the EFB mode as a significant initial imperfection. The test has also been simulated by elasto-plastic buckling analyses considering stress-strain relationship and imperfections in the test vessels. The result of the test and its analysis have showed the applicability of the modified equations.
Moreover, a series of verification analyses conducted for the modified equations with 3D buckling analysis models under the conditions in FRs power plant. These verification analysis results confirmed the contribution of the factors to the buckling strength such as initial imperfection and material, and showed that the modified equations are applicable to the vessels in FRs power plant.
Study on Fatigue Life of Vehicle Fuel Tank Under Random Vibration Environment
Authors: Tang Yuanzhang , Yang Zhirong , Gao Haibo , Lin Zhiguo , Qin Du 
Published: November 2022

Abstract
The working environment of oil tank is complex and changeable. Aiming at the problem that it is difficult to predict the high cycle fatigue life of a certain vehicle fuel tank, The fatigue life of the tank was studied. Firstly, the natural frequency and modal shape of the structure are obtained by identifying modal parameters of the structure using Eigensystem Realization Algorithm (ERA). Then, the simulation model is established by SolidWorks, and imported into ANSYS for modal analysis. Compared with the bench test, the results show that the errors between dynamic characteristic of modal simulation and modal test are acceptable, which verify the accuracy of simulation model. Finally, the fatigue life of fuel tank is analyzed by frequency domain analysis method in ANSYS nCode DesignLife. The results show that the weak position of the oil tank vibration is always unchanged under multiple power spectral density (PSD) spectrum types, and its life decreases with the increase of PSD amplitude at low frequency. To further verify the accuracy of numerical simulation results, the PSD spectrum corresponding to the shortest life tank will select for random vibration fatigue life experiment in the future.
Failure Estimation Methods for Steam Generator Tubes With Wall-Thinning or Crack
Authors: Yamaguchi Yoshihito , Mano Akihiro , Li Yinsheng 
Published: November 2022

Abstract
The steam generator (SG) tube is one of the important components in pressurized water reactors. Flaws such as wall-thinning or stress corrosion cracking have been reported in SG tubes. The burst pressure where both the internal and external pressures from the primary and secondary coolant systems are considered must be predicted to assess the structural integrity of SG tubes. Burst tests were performed by various organizations. On the basis of the test results, failure estimation methods were proposed. In this study, previous burst test data and existing failure estimation methods for SG tubes with wall-thinning or crack were investigated. As a result, the coefficient of the existing estimation method for SG tube with uniform wall-thinning was updated. In addition, failure estimation methods that are suitable for SG tubes with crack or local wall-thinning were proposed by considering the effects of the flaw shape and size on the burst pressure. The applicability of the failure estimation methods was confirmed by comparing the predicted results with the burst test data in actual SG tubes.