bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Assessment Method for Wrinkle Defects in Composites
Authors: Shen Chuanchuan , Ma Li , Zheng Jinyang 
Published: October 2020

Abstract
Fiber reinforced composite structures have been increasingly used in the field of pressure vessels and piping. Various process-induced defects of composite structures are accumulated during their manufacture processes for the variations of environment temperature and humidity, pre-stress of fiber and curing temperature. Wrinkle defect is one of the most frequently encountered defects in fiber reinforced composite structures. In this paper, a new method for detecting wrinkle defects based on the relation of the displacement fields between flawed and flawless areas is proposed. The orthotropic finite element analysis codes combined with wrinkle model were developed based on Matlab platform to predict structural responses of laminates under three different loading types, including transverse compression, axial tension and bending. The effective elastic moduli disturbed by wrinkles were determined based on a mesomechanics model and a two-step homogenization procedure. Two different wrinkle models including definite and heterogeneous distributed models were considered. It is found that the out-of-plane displacement obviously increases at the wrinkle region under the axial load. The fluctuant displacement fields under axial tensile load can be clearly observed when the heterogeneity wrinkle model is considered. However, the transverse compression cannot produce any displacement distortion. All the results bring us a new idea of non-destructive evaluation for composites, wherein the defects that mainly weakening the stiffness can be detected by measuring the displacement distribution under some specified loads.
Dynamic Analysis of Liquid Sloshing for Shipboard Pressure Vessel
Authors: Li Qi , Tang Hui , Zhang Fujun , Wang Zhijian , Shi Qianyu 
Published: October 2020

Abstract
With the development of pressure vessel industry in China, more and more pressure vessel is widely used in the aerospace, automobile, marine project and other fields. The liquid sloshing in the device could bring adverse effect on the safety operation of the pressure vessel under the extrinsic excitation, such as the impact load results in the failure of device structure. Thus, dynamic analysis of liquid sloshing for the shipboard pressure vessel is significant. According to the little research on the design criteria and the method of the shipboard pressure vessel, this paper focuses on the research of the transient sloshing of the internal liquid in the shipboard pressure vessel. In this paper, during analyzing the liquid sloshing dynamic of the shipboard pressure vessel, an obvious cycle is got. Considering the operation condition of lateral inclination, longitudinal inclination and heave in the complex marine environment, the liquid sloshing character is obtained and compared through the liquid surface height curve and the wall sloshing pressure curve, which has great influence on the piping layout of the pressure vessel. Moreover, it is beneficial to restrain sloshing through installing baffle inside the pressure vessel. This may provide a project reference to liquid sloshing design of the shipboard pressure vessel.
Microstructure Evolution and Creep Rupture Behavior of Modified 9Cr-1Mo Steel Welded Joint
Authors: Ren Facai , Tang Xiaoying , Xu Jinsha , Si Jun , Yuan Yiwen 
Published: October 2020

Abstract
Microstructure evolution and creep rupture behavior of modified 9Cr-1Mo steel welded joint used for steam cooler in high pressure heater system were systematically studied in this paper. Creep tests were carried out using uniaxial creep specimens machined from the normalized and tempered plate at 818K and 838K with the stresses ranging from 150 to 225MPa. The curve of stress vs. rupture time was achieved to evaluate the creep rupture life of modified 9Cr-1Mo steel welded joint. The creep data were analyzed in terms of Norton’s power law, Monkman-Grant relation and modified Monkman-Grant relation. Microstructure before and after creep exposure were analyzed by optical microscope, scanning electron microscope and transmission electron microscope, to further explain the rupture mechanisms of modified 9Cr-1Mo steel welded joint.
Consideration of Wind Loads in Fitness for Service Assessment of Storage Tanks
Authors: van Zyl Gys , Long Stewart 
Published: October 2020

Abstract
Wind actions are important to consider when performing fitness for service assessment on storage tanks with damage. Tank design codes typically have rules where a design wind velocity is used to determine required dimensions and spacing of wind girders, and a uniform wind pressure is used to evaluate tank anchorage for uplift and overturning due to wind actions. These rules are of little use in a fitness for service assessment of localized damage, as the actual distribution of wind pressure on the wall and roof of a cylindrical tank is far from constant, and a better evaluation of the wind pressure distribution is desired when performing a level 3 fitness for service assessment. API 579/ASME FFS-1 provides no direct guidance relating to the application of wind loading but refers to the American Society of Civil Engineers Standard ASCE/SEI 7. Other international codes relating to wind loads, such as Eurocode EN-1991-1-4 and Australia/New Zealand Standard AS/NZS 1170.2 also contain guidance for the evaluation of wind actions on cylindrical tanks. This paper will present a review of these international codes by comparing their guidance for wind actions on cylindrical tanks, with specific emphasis on how this may affect a level 3 fitness for service assessment of a damaged storage tank.
Gas Supply Reliability Analysis of a Natural Gas Pipeline System Considering the Effects of Demand Side Management
Authors: Li Yichen , Gong Jing , Yu Weichao , Huang Weihe , Wen Kai 
Published: October 2020

Abstract
At present, China has a developing natural gas market, and ensuring the security of gas supply is an issue of high concern. Gas supply reliability, the natural gas pipeline system’s ability to satisfy the market demand, is determined by both supply side and demand side, and is usually adopted by the researches to measure the security of gas supply. In the previous study, the demand side is usually simplified by using load duration curve (LDC) to describe the demand, which neglects the effect of demand side management. The simplification leads to the inaccurate and unreasonable assessment of the gas supply reliability, especially in high demand situation. To overcome this deficiency and achieve a more reasonable result of gas supply reliability, this paper extends the previous study on demand side by proposing a novel method of management on natural gas demand side, and the effects of demand side management on gas supply reliability is analyzed. The management includes natural gas prediction models for different types of users, the user classification rule, and the demand adjustment model based on user classification. Firstly, An autoregressive integrated moving average (ARIMA) model and a support vector machine (SVM) model are applied to predict the natural gas demand for different types of users, such as urban gas distributor (including residential customer, commercial customer, small industrial customer), power plant, large industrial customer, and Compressed Natural Gas (CNG) station. Then, the user classification rule is built based on users’ attribute and impact of supplied gas’s interruption or reduction. Natural gas users are classified into four levels. (1) Demand Fully Satisfied; (2) Demand Slightly Reduced; (3) Demand Reduced; (4) Demand Interrupted. The user classification rule also provides the demand reduction range of different users. Moreover, the optimization model of demand adjustment is built, and the objective of the model is to maximize the amount of gas supply for each user based on the classification rule. The constraints of the model are determined by the classification rule, including the demand reduction range of different users. Finally, the improved method of gas supply reliability assessment is developed, and is applied to the case study of our previous study derived from a realistic natural gas pipeline system operated by PetroChina to analyze the effects of demand side management on natural gas pipeline system’s gas supply reliability.
Correlation Between Thermal Desorption Spectrum Features and Creep Damage
Authors: Zhou Yu , Fan Zhichao , Chen Xuedong , Jiang Huifeng , Jazaeri Hedieh , Bouchard Peter John 
Published: October 2020

Abstract
The analysis of the spectrum features of thermal desorption spectroscopy (TDS) using the desorption-rate profile against temperature is widely applied to investigate the hydrogen kinetics including diffusion and trapping in metallic materials, which is related to hydrogen embrittlement. Recently the TDS spectrum features such as the peak magnitude and the peak area have been used for qualitative assessment of creep damage, although there is still a lack of theoretical understanding on the correlation between TDS spectrum features and creep damage. In this paper, creep voids inducing creep damage are considered as the only kind of hydrogen traps in steels. The relationships between the TDS spectrum features and creep damage of ferritic steels are investigated through parameter analysis of the modified McNabb-Foster model together with the Oriani assumption, which can describe hydrogen evolution during thermal desorption. It is found that the peak area of TDS spectrum is independent of the trap binding energy, and it is proportional to the trap density, demonstrating that it could be a good indicator for creep damage. The creep damage can be characterized as a power-law function of the peak area of TDS spectrum, indicating TDS as a promising semi-destructive characterization method for creep damage of metallic steels.
Passive Control Techniques for Seismic Protection of Chemical Plants
Authors: Minagawa Keisuke , Paolacci Fabrizio 
Published: October 2020

Abstract
Seismic damage of chemical plant facilities (pressure vessels, piping, storage tanks, etc..) can causes human and economic losses as well as heavy environmental damages. Therefore, it is of paramount importance to reduce such a consequences. The passive control techniques (PCT) as dampers or base isolation can represent an effective technique to mitigate the major damage caused by earthquakes. Viscous dampers, tuned mass dampers and base isolators are well-known passive control devices successfully applied to civil structures, as demonstrated during the last big events as Northridge earthquake in 1994, the Kobe earthquake in 1995, the Great East Japan earthquake in 2011. The scarce application to major hazard industrial facilities as chemical plants poses some questions, including the selection of suitable devices, their real applicability and effectiveness, because of the strict requirements of chemical plant equipment in terms of safety and business continuity. Therefore, this study aim at analyzing the possible applications of the most renew passive control techniques for seismic protection for chemical plant components. In this respect, a complete review of typical seismic damage of industrial (chemical) facilities and the investigation of the applicability of PCT as mitigation strategy is offered for all possible structural typologies of units presents in a plant.
Further Evidence of Margin for Environmental Effects, Termed Fen-Threshold, in the ASME Section III Design Fatigue Curve for Austenitic Stainless Steels Through the Interaction Between the PWR Environment and Surface Finish
Authors: McLennan Alec , Morley Andrew , Cuvilliez Sam 
Published: October 2020

Abstract
Fatigue rules within the ASME Boiler and Pressure Vessel Code have undergone significant change over the past decade, especially with the inclusion of Code Case N-792-1 as an acceptable method to describe the effects of BWR and PWR environments on the fatigue life of components. The incorporation of the environmental effects into the fatigue calculations is performed using an environmental factor, Fen, which attempts to describe the difference in fatigue life of polished specimens between air and high-temperature water environments. The Fen depends on parameters such as the temperature, dissolved oxygen and strain rate.
The deleterious effects on fatigue life of a wide range of other factors are not accounted for by the standard constant amplitude testing, performed on small polished specimens that was used to develop the mean air curve. These factors are accounted for in the design curve, which is defined by adjusting the mean air fatigue curve with transference factors.
Evidence, obtained in recent years, now suggests that the assumed deleterious effect of surface finish on fatigue life may be excessive. Therefore, the combination of the air design fatigue curve and Fen results in overly-conservative estimates for fatigue life in high temperature water environments. Approaches have been developed to quantify the scale of this excess-conservatism and define this as a margin within the design fatigue curve that can be used to offset Fen. In the ASME framework this is termed Fen-Threshold.
This paper presents further evidence in support of the approach by extending the database of test results to 316-type steels and extending the range of environmental and loading conditions. The additional stainless steel data demonstrates that the size of the margin is insensitive to strain amplitude over an extended range of strain amplitudes. Furthermore, the analysis indicates that in conditions where the environmental effect is low (less than the value of Fen-Threshold) the margin remains great enough to offset the entire Fen, returning such sites to an assessment against the air design curve.
This paper also presents an extension of the research program to nickel based alloys through testing of Alloy 600. The intent is to investigate whether there is evidence of similar excessive conservatism that can be translated into an equivalent margin for environmental effects in nickel-based alloys.
Hydrogen Effects on Fatigue Life of Welded Austenitic Stainless Steels Evaluated With Hole-Drilled Tubular Specimens
Authors: Kagay B. , San Marchi C. , Pericoli V. , Foulk J. 
Published: October 2020

Abstract
Limited fatigue data exists for small-volume welded austenitic stainless steel components typically employed in hydrogen infrastructure due to the difficulty of testing these components with conventional specimen designs. To assess the fatigue performance of orbital tube welds of austenitic stainless steels, a hole-drilled tubular specimen was designed to produce a stress concentration in the center of the orbital weld. Fatigue life testing was performed on welded and non-welded 316L stainless steel hole-drilled tubular specimens, and the effects of hydrogen were evaluated by testing specimens with no added hydrogen and with internal hydrogen introduced through gaseous precharging. When accounting for the differences in flow stress caused by microstructural variations and the presence of internal hydrogen, the total fatigue life and fatigue crack initiation life of the welded and non-welded tubes were comparable and were reduced by internal hydrogen. In addition, the fatigue life results produced with the hole drilled tubular specimens were consistent with fatigue life data from circumferentially notched stainless steel specimens that have a similar elastic stress concentration factor. To better understand the mechanics of this specimen geometry, mechanics modeling was performed to compare the stress and strain distributions that develop at the stress concentration in the hole-drilled tubular and circumferentially notched specimens during fatigue cycling.
A Review of Temperature Reduction Methods in Codes and Standards for Pipe Supports
Authors: Mayes Alex , Wiseman Phillip , Gawande Kshitij P. 
Published: October 2020

Abstract
American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section III, Division 1, Subsection NF, Subparagraph NF-3121.11 does not require that thermal stresses in supports be evaluated. Historically, pipe support engineers have not been concerned with thermal stresses of pipe and component supports, but determining material temperature limits and allowable stresses have been a major role in designing and analyzing supports. Thus, heat transfer is often investigated in finding the temperature of pipe supports and parts of pipe supports that are not in direct contact with pipe or pipe components. There are also other Codes and standards that permit a reduction of temperature away from the outer surface of pipe or pipe components. In some but not all cases, Codes and standards explicitly address reduction of temperature for applications of utilizing thermal insulation. Additionally, the temperature distribution is established by specific geometrical parameters and their respective equations for employment by the pipe support engineer. These reductions are explored by utilizing fundamentals of heat transfer. Additionally, steady-state and transient thermal Finite Element Analyses (FEA) are used to establish computational models of simple geometric bodies in a range of atmospheric conditions. The effects of insulation on the thermal distribution are also represented through closed form solutions and FEA. The results of these analyses allow for assessment of, and recommendations for, the treatment of temperature reduction in Codes and standards.
Welded Attachments and Hydrostatic Pressure Testing Rules for Diffusion Bonded Heat Exchangers
Authors: Aakre Shaun R. , Jentz Ian W. 
Published: October 2020

Abstract
The mission of the U.S. Department of Energy (DOE), Office of Nuclear Energy is to advance nuclear power in order to meet the nation’s energy, environmental, and energy security needs. Advanced high temperature reactor systems will require compact heat exchangers (CHX) for the next generation of nuclear reactor plant designs. A necessary step for achieving this objective is to ensure that the ASME Boiler and Pressure Vessel Code, Section III, Division 5 has rules for the construction of CHXs for nuclear service.
Construction of Alloy 800H diffusion bonded Printed Circuit Heat Exchangers (PCHEs) involves multiple controlled welding processes. The primary diffusion bonding process creates a uniformly bonded PCHE body featuring a microchannel core. Secondary welding processes are needed to attach headers and nozzles to the PCHE body, forming a complete CHX. The quality of these welding processes is ensured by following the appropriate ASME Section IX weld qualification procedures.
Experience in constructing both 316L and 800H PCHEs has given a set of acceptable attachment weld configurations and procedures. Headers were attached to the diffusion bonded block surface using full penetration welds, as required by Class A design. The integrity of these attachment welds was demonstrated through hydrostatic pressure testing.
Check Valves in Nuclear Power Plants: ASME OM Code Requirements and Industry Compliance
Authors: Ezekoye L. Ike , Rain Mark , Thygesen Theodore E. 
Published: October 2020

Abstract
Nuclear power plants use lots of valves in different applications. Each valve type has specific tasks to perform. The vast majority of safety related valves are monitored during plant operation to ensure they are operable and can be relied upon to do their design functions. Unfortunately, check valves do not fall in the category of valves that can be readily monitored because of how they are designed; usually with all operating components internal to the pressure boundary. Since they are not easily monitored externally, plant operators typically disassemble and inspect them to assess the internal conditions and determine what actions to take, which can be either repair, replace, or use as found. However, not all check valves get inspected for a number of reasons resulting in some valves running to failure. In this paper, the authors present actions the nuclear industry has used to comply with ASME OM Code requirements (8) on check valves and US NRC regulatory activities in this area. The paper also covers the role the nuclear industry and other organizations have played to improve check valve reliability.
Buckling Test of Thin-Walled Metallic Cylindrical Shells Under Locally Distributed Axial Compression Loads
Authors: Jiao Peng , Chen Zhiping , Ma He , Zhang Delin , Wu Jihang , Ge Peng , Gu Yanan 
Published: October 2020

Abstract
Thin-walled cylindrical shell structure not only shows the highly efficient load carrying capacity but also is vulnerable to buckling instability failure. In practical application, these structures are more easily subjected to locally distributed axial compression load, which is a more common non-uniform loading case. However, until now, the buckling behaviors of thin-walled cylindrical shells under this kind of loading case are still unclear, and there are also few relevant buckling experiments. In order to fill this research gap as well as reveal the relevant failure mechanism of thin-walled cylindrical shell structures, in this paper buckling tests of thin-walled metallic cylindrical shell structures under non-uniform axial compression loads are successfully performed. In this regard, the design and characteristics of two cylindrical shell test specimens subjected to different pattern of non-uniform compression loads are mainly introduced. Meanwhile, as the important parts for conducting this buckling experiment, the axial compression buckling test rig as well as the real-time acquisition measurement system is also presented in details. Results indicate that locally distributed axial compression loads play a pivotal role in the buckling behaviors of thin-walled cylindrical shell, not matter from the point of view of load carrying capacity, shell deformation process or failure mode. The experiments carried out in this work can be served as a benchmark for related numerical simulation afterwards. Furthermore, the obtained test results can also provide some guides for the design and application of thin-walled cylindrical shell in actual engineering.
Applicability of Formula of the Irradiation Assisted Stress Corrosion Cracking Rates for Neutron-Irradiated Type 316L Stainless Steels to Various Types of Stainless Steels Under Boiling Water Reactor Condition
Authors: Koshiishi Masato , Seto Hitoshi , Tanaka Shigeaki , Obata Ryoji 
Published: October 2020

Abstract
The Hashimoto-Koshiishi model is the predictive mechanistic model for crack growth rates (CGRs) of stress corrosion cracking (SCC). The simplified formula of the Hashimoto-Koshiishi model was developed for the calculation of CGRs of irradiated Type 316L stainless steels (SSs). This study evaluated the applicability of the developed formula to various types of stainless steels by analyzing experimental data of CGRs. The developed formula was determined to be applicable for Type 304L SSs and 316NG SSs as well as Type 316L SSs. On the other hand, the formula was unsuitable for irradiated Type 304 SSs because the mechanical properties and the Cr concentrations at the grain boundaries of Type 304 SSs were different from these quantities for Type 316L SSs.