bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Testing of Buried Pipelines Subjected to Ground Displacement Due to Seismic Motion
Authors: Chang Che-Yu , Yang Hsuan-Chih , Chang Wei-Kuang 
Published: November 2024

Abstract
Ground displacement is considered the major natural hazard in causing damage to pipelines. Although the most effective method to reduce pipeline damage is routing the pipelines away from the ground movement potential areas, the pipelines in Taiwan unavoidably pass through faults, soil liquefaction potential areas, and sensitive areas of landslides, given that thirty-six active faults are crossing the island. Currently, available researches show that quasi-static testing is utilized to study the pipeline behavior under fault displacement. This paper presents laboratory testing design and results of buried pipelines subjected to ground displacement due to seismic motion. Pipelines are buried in a uniaxial shear box which is designed to introduce fault displacement caused by seismic motion. Different pipeline diameters are tested for comparison to study the diameter effect of pipelines. Protection measures such as different backfill materials and various burial depths are also tested to possibly offer suggestions on pipeline damage mitigation methods. The dynamic behavior of the pipelines is presented by the measurements collected by the strain gauges and accelerometers located on the pipelines. This study provides valuable information on the dynamic behavior of buried pipelines subjected to ground displacement due to seismic motion, which can enhance the design of the pipeline systems for seismic damage mitigation.
Study on Fracture Characteristics of Pipeline Girth Weld Based on Curved Wide Plate Tensile Test
Authors: Zhang Tieyao , Shuai Yi , Zhang Junjie , Shi Lei , Lv Zhiyang , Zhang Yinhui , Xia Gang , Li Xingtao 
Published: November 2024

Abstract
It is the premise and foundation of pipeline integrity evaluation to clarify the fracture toughness and strain capacity of pipeline girth weld. The curved wide plate is very close to the full-size pipeline in geometric size. Compared with the small-size specimens in the laboratory, the crack tip constraint state of the curved wide plate specimen is the closest to the real pipeline structure, which is the main way to study the deformation ability of the girth weld in the pipeline industry. In this study, wide plate specimens with different girth weld positions of 1016 mm × 15.0 mm L485M pipeline were intercepted, and different sizes of cracks were machined in the weld center of wide plate specimens. The slow rate uniaxial loading of wide plate specimens with cracks was carried out by kiloton tensile testing machine until the specimens were broken. During the test, the double COD (Crack opening displacement) gauge was used to monitor the opening displacement of the crack mouth near the crack, four high-precision displacement sensors were used to monitor the deformation of different positions of the specimen, and 52 strain gauges were used to monitor the axial and circumferential strains of different positions of the specimen. Through the experimental study, the strain response and fracture characteristics of the curved wide plate specimen with weld center crack under external load are obtained, which provides a data basis for the subsequent extensive parameter research, and also provides a reference for the safety evaluation of the cracked pipeline.
Sensor-Less Semiactive Damper That Automatically Switches Damping Force Using 3-Phase Motor and Relay
Authors: Matsuoka Taichi 
Published: November 2024

Abstract
The author developed a sensor-less semiactive damper that consists of a three-phase direct drive motor whose damping force is automatically switched by a rectifier circuit and relay, using the motor instead of a speed sensor. It is more compact and has higher performance compared to previous damper using DC motor. The direct drive motor is attached to the end of the shaft of the ball screw mechanism. Since the voltage between the motor terminals is proportional to the rotation speed, when the speed exceeds a border level, the voltage rises to the operating voltage of the relay, which closes the load circuit of the relay and causes a short circuit between the terminals, switching to the high damping force. The resisting force characteristics of the damper were measured by experiments, and a theoretical equation was derived. Next, the damper was attached to a one-degree-of-freedom system, and seismic wave excitation experiments were conducted. Experimental results show a little advantage in vibration reduction in the semiactive case which switches automatically, compared to a passive case where the damping coefficient of the damper is not switched. The experimental results agree with the calculated results mostly, and vibration control effect of the damper is confirmed.
An Overview of Codes and Standards for Electrolyzer Applications
Authors: Quackenbush Karen , Panicker Jitesh 
Published: November 2024

Abstract
This paper provides an overview of key codes and standards relating to electrolyzers. It will highlight similarities and differences between requirements published in ASME Section VIII, Division 1 Code Case 3078, ANSI/CSA 22734, NFPA 2, and applicable national and international standards. The paper concentrates on design considerations, materials requirements, and pressure testing requirements.
Tensile Testing for Determination of Mechanical Properties of Recycled PET-G Plastics
Authors: Alvarez Avianna , Ma Qin , Mckenzie Janice 
Published: November 2024

Abstract
Polyethylene terephthalate glycol (PET-G) has become one of the most widely used industrial thermoplastics due to its superior characteristics when compared to PET as well as other common plastics in industry. Because of its unique and favorable characteristics, PET-G has wide applications for making medical devices. The research teams led by Professor Michael Moor and Professor Michael Davidson at Loma Linda University, School of Allied Health Professions and Department of Orthotics & Prosthetics (O&P), have been working toward developing low-cost injection molding equipment to provide affordable, viable, and feasible O&P care for the most economically challenged individuals around the world. As part of their work, recycled PET-G plastics were melted and then thermoformed into plaster molds under various conditions. Their mechanical properties are highly desirable.
In this study, tensile properties of the PET-G recycled plastic dog-bone coupons were obtained and tested for modulus of elasticity, yield strength, tensile strength, and ductility. ADMET eXpert 7600 equipped with MTESTQuattro Materials Testing Software was used as the testing machine. The load cell was 1000 lb. in capacity with crosshead movement, and the vertical test space can accommodate up to 41 inches. For consistent testing, ASTM standards were employed in preparation of the specimens and testing procedures. It was found that the present recycled PET-G plastic yields results of tensile strength of approximately 47 MPa, 0.2% offset yield strength of approximately 35 MPa, tensile modulus of approximately 1.9 GPa, and ductility in the range of 170–250 percent elongation. All these findings are in agreement with literature for similar recycled PET-G plastics.
Failure Analysis and Materials Degradation Properties Assessments in an Aged Hydroprocessing 347H Austenitic Stainless Piping
Authors: Batts Kevin , Hau Jorge , Penso Jorge , Caldwell Eric , Dalal Mitul 
Published: November 2024

Abstract
A leak occurred on the suction 347H SS piping of a pump connected to one of the two reactors of a train during start-up of a hydrocracker unit while the other two-reactor train was online. Operations initiated shutdown activities and emergency response.
Destructive testing revealed a crack in a weld in the pump suction piping. This weld had recently undergone inspection. The results showed no indications of a crack. The UT phased array method using shear waves is an industry standard, but this crack was undetectable with standard NDE due to a combination of the thickness of the pipe, weld root geometry, and the weld metal properties. These features caused sound waves to reflect in a way that prevented distinction of waves reflected from a defect.
The crack in the pump suction line of the reactor had initiated at a stress riser on the surface geometry of the weld root. The weld had impact testing results in the range of 18–42 J (13–31 ft-lb), and elongation in the range of 15–16% at ambient conditions, suggesting some embrittlement have taken place. For new 347H SS pipe and welds, approximately 108–136 J (80–100 ft-lb) would be the expected impact test range and &gt; 35% elongation. The toughness and elongation had been reduced by the precipitation of brittle phases over the service life of the weld at about 427 °C (800 °F). The usual maintenance procedure to dismount the pump was achieved by hitting the flange joint with sledgehammers. This introduced high strain rate loading that caused the cracking in these embrittled welds.
Formulation of the Stress Corrosion Crack Growth Rates Based on the Theoretical Strain Rate Model for Light Water Reactors
Authors: Koshiishi Masato , Akazawa Dan , Miura Yasufumi , Kako Kenji 
Published: November 2024

Abstract
This study developed a formulation method for SCC growth rate based on SCC growth theory and the theoretical equation of strain distribution ahead of the crack tip. The SCC growth rate in a light water reactor environment is usually expressed in the form of a power law of the stress intensity factor, K. However, the power law of K was originally introduced with reference to the Paris law in fatigue crack growth and it is not based on SCC growth theory. Based on the theoretical equation for the strain rate ahead of the crack tip of a growing crack, it is appropriate to express the SCC growth rate in the form of a power law of log(K/K0). On the other hand, the conventional equation in the form of a power law of K is based on the strain distribution ahead of the stationary crack and it is not theoretically appropriate for growing cracks. Applicability of the proposed formulation method was also confirmed for several types of materials in the present study.
Research on Effects of Surface Finishing and Mean Stress on Fatigue Lives of Notched Specimens - Definition of Fatigue Life of Notched Specimen Using Crack Growth Analysis
Authors: Itatani Masao , Ogawa Takuya , Takanashi Masahiro , Wang Yun , Nomura Yuichiro , Kitamura Yoshihide 
Published: November 2024

Abstract
DFC and DFC2 subcommittees in the Japan Welding Engineering Society developed a new approach of fatigue analysis method. This fatigue analysis method has been made several modifications and incorporated into the JSME Environmental Fatigue Evaluation Method 2022 Edition (JSME S NF1-2022). Research on effects of surface finishing and mean stress on fatigue lives of notched specimens have been followed by DFC3 and DFC4 subcommittees.
In the DFC4 subcommittee, it was investigated the evaluation method of combined effects of stress concentration and surface finish, and stress concentration and mean stress on the fatigue properties of ferritic steels. DFC4 subcommittee evaluated the load controlled fatigue test results using notched round bar specimens. The fatigue tests were finished when the displacement over notch mouth exceeded the prescribed value and crack depth was measured on the fracture surface of specimens. Although the fatigue lives of specimen should be compared based on the same crack depth, crack depths are different among the specimens when the fatigue test finished. To compare the fatigue lives based on the same standard life among the specimens, the fatigue crack growth analysis was conducted. The stress intensity factor (SIF) of surface crack in notched round bar specimen was investigated first. Next, the suitable fatigue crack growth rate (FCGR) for tested material was investigated among the existing FCGR equations and determined. The crack depth for fatigue life evaluation was determined to be 2 mm and influence of FCGR, stress amplitude and stress concentration factor Kt on N2mm were investigated by case studies.
It was found that the effects of fatigue crack growth rate, stress amplitude and stress concentration factor Kt on the N2mm were relatively smaller for low-alloy steel than carbon steel because the tested stress amplitude were higher for low-alloy steel than carbon steel.
Elastic Properties of Randomly Oriented Fiber-Reinforced Composites Using ANSYS Material Designer
Authors: Graham Luke , Ma Qin 
Published: November 2024

Abstract
Advanced engineering materials such as fiber-reinforced composites are gradually dominating the modern industry and becoming one of the leading engineering materials on the market. Before manufacturing any structure made of these advanced materials, it is often critical to first obtain their elastic properties. Traditional methods for quantifying elastic properties include analytical and experimental methods. Analytical methods may be used to obtain closed-form solutions, but these methods are limited only to specific types of simple problems. Experimental methods may be derived using simple protocols, but the tests can be expensive and time-consuming. Therefore, numerical analysis can be used to obtain the necessary elastic properties of these advanced engineering materials. Starting at release 19.2 in late 2018, ANSYS introduced Material Designer (MD). The MD essentially allows the elastic properties of advanced materials to be estimated more affordably by using numerical simulation. In this study, ANSYS MD is applied to predict the elastic constants for randomly oriented fiber-reinforced composites, including tensile and shear moduli and Poisson’s ratios. The results were compared with existing models in literature and with available experimental data.
Microstructural Evolution and Creep Behavior of T92/HR3C Dissimilar Welds Used in China Plants
Authors: Che Chang , Cong Yu , Yu Jianming , Chen Xinzhong , Wang Hao 
Published: November 2024

Abstract
Creep rupture experiments were conducted at 650°C under different stress conditions (70MPa, 60MPa, 50MPa) on a T92/HR3C welded joint that had been in service for 105 hours. Scanning electron microscopy and optical microscopy were used to observe and quantitatively analyze the microstructure and precipitates of the samples before and after creep rupture, and the hardness distribution of the joint was measured. The results show that the size variation of Laves phases and M23C6 carbides significantly impact the creep failure of the welded joint. With the increase of creep time, the size of Laves phase in fine-grained heat-affected zone (FGHAZ) on T92 side increases. In addition, the rapid coarsening of M23C6 carbide in this area is an important reason for the decrease of creep strength of welded joints. Further EBSD analysis of FGHAZ revealed changes in the microstructure, including grain coarsening and a reduction in GND values, which were important factors contributing to the degradation of T92 FGHAZ performance. After creep rupture, the hardness in the T92 FGHAZ significantly decreased, becoming the region with the lowest hardness in the entire welded joint, ultimately leading to failure and rupture in this area.
Investigation on Carbon Emission Reduction of Non-Metallic Composite Pipeline for Hydrogen Transportation
Authors: Shi Jianfeng , Xia Ruoxi , Zheng Jinyang , Wang Zhongzhen , Zheng Xinyu , Yao Riwu 
Published: November 2024

Abstract
Non-metallic composite pipelines possess remarkable flexibility and exceptional resistance to corrosion. Compared to traditional metallic hydrogen pipelines, non-metallic composite hydrogen pipelines effectively mitigate the challenges of hydrogen corrosion and brittleness, positioning them as a promising alternative for large-scale, low-cost hydrogen transportation. Moreover, compared to traditional metal pipelines, non-metallic composite hydrogen pipelines exhibit lower wall roughness, effectively reducing hydraulic losses and offering carbon reduction advantages. Within the lifecycle of non-metallic composite pipelines, carbon emissions during the operational stage predominate. Consequently, this study proposes a method for calculating carbon emissions associated with the operational stage of non-metallic composite hydrogen pipelines. This method involves calculating the pipeline’s friction coefficient, followed by hydraulic loss calculations, and then analyzing carbon emissions based on the electricity consumption of the hydrogen pumps. The results obtained from this method were compared with standards, and a good agreement was demonstrated, confirming the method’s reliability. Subsequently, comparisons with metal pipelines revealed that utilizing non-metallic composite pipelines can effectively reduce carbon emissions. Additionally, the influence of pipeline diameter, hydrogen pressure, and flow velocity on friction losses and carbon emissions were analyzed in detail. The results of this study can guide the design of structural and operational parameters of non-metallic hydrogen pipelines, better leveraging the advantages of non-metallic composite pipelines in hydrogen transportation.
Investigation on Crack Propagation Failure Modes of Short Carbon Fiber Reinforced Polyethylene Electrofusion Joints
Authors: Zong Xinwei , Yao Riwu , Shi Jianfeng 
Published: November 2024

Abstract
Electrofusion joint is a principal connection method within non-metallic pipeline systems, and the mechanical strength of electrofusion joints is of great importance to achieve safe operation of pipeline systems. By manufacturing the electrofusion joints with short carbon fiber reinforced thermoplastic composites (SCFRTCs), the mechanical strength of electrofusion joints has been significantly improved, which shows great potential in mechanical enhancement of electrofusion joints. However, due to inherent stress concentrations within the joint structure and the limited ductility characteristic of SCFRTCs, SCFRTCs electrofusion joints are prone to crack propagation failure. Elucidating the failure mechanics of SCFRTCs electrofusion joints is vital for their continuous refinement and the secure operation of pipeline systems. In this study, SCFRTCs were first prepared and their fundamental mechanical properties were investigated. Subsequently, electrofusion joints were manufactured by SCFRTCs. A finite element models, combined with contour integral method, was developed to ascertain the crack propagation failure mode of SCFRTCs electrofusion joints. The influence of yield strength of SCFRTCs and wall thickness of joints on crack initiation of SCFRTCs electrofusion joints were systematically analyzed. The results demonstrated that the stress level in most areas along the wall thickness is low when the crack in the joint initiates. Increase in joint wall thickness and material yield strength can improve the internal pressure of crack initiation, but the utilization rate of materials strength decreases gradually. Additionally, short-term bursting tests of SCFRTCs electrofusion joints were conducted to determine the bursting pressures of electrofusion joints with varying wall thicknesses. By analyzing the crack morphology on the cross-sections of the bursting joints, it is found that after crack initiation, the crack is driven by internal pressure and gradually propagates until the joint fails. The results of this study can provide reference for the design and application of SCFRTCs electrofusion joints.
Mastering Critical Factors Affecting Toughness Degradation Is Key to Effective Use of Duplex Stainless Steel in Pressure Vessels
Authors: Tigerstrand Claes , Pilhagen Johan , Jonsson Jan Y. 
Published: November 2024

Abstract
Hence, the overall aim with the paper is to evaluate if leaner duplex stainless steels such as S32101 and S82441 justify a broader use as a cost-effective alternative to more established grades, i.e., S31803, S32205 and S32304 by including them in ASME Section VIII Division 2. This by considering their leaner alloying composition, and how it affects mechanical properties at both low and high temperatures of welded components for use in pressure vessels. The focus is on evaluating the potential allowable stresses in allowable temperature range using the stipulated design criteria for the different design routes. Moreover, to review and propose a method originating from the European pressure vessel standard EN 13445 on how to assess design against brittle fracture for both base and weld metal. Furthermore, discuss the risk for encountering embrittlement at the upper application temperature limit 316°C (600°F) in the ASME code which is strongly dependent on exposure time.
Inelastic Response Analysis of 2DOFs to Earthquake Motions Based on Superposition of Elastoplastic Response of Each Mode
Authors: Taniguchi Tomoyo , Shoji Yasumasa , Kimura Yukinobu 
Published: November 2024

Abstract
This paper develops the time history analysis of the elastoplastic response of the 2DOF, consisting of two masses and springs that exhibit bilinear hysteresis, being subjected to a base excitation, by superposing the time history of elastoplastic response of each mode. The essence of the proposed analysis is that the response of the 2DOF during the yielding of any springs consists of the mode frequencies, shapes and dampings that are readily specified by the eigenvalue problem employing the mass and the secondary stiffness of the spring yielded. First, the equations governing the response of each mode according to the state of spring and all quantities needed for them are described in detail. Next, the displacement history of each mode and that in the global coordinates system are numerically and simultaneously analyzed at every time step, because the yielding and turn-around points of each spring are only verifiable in the global coordinates system. Once the response exceeds the elastic limit or the turn-around points of each spring, the equations of motion of each mode are switched to those corresponding to the next state of springs. Finally, the accuracy of the proposed method is thoroughly discussed. Moreover, the force-displacement diagram of each mode is presented. The applicability of the SRSS method is also examined.
Method for Shape Imperfection Control in Buckling of Ellipsoidal Heads Using a 3D Laser Scanner
Authors: Shen Tao , Li Keming , Zheng Jinyang 
Published: November 2024

Abstract
Ellipsoidal heads are commonly used as components of pressure vessels. Shape imperfections such as out-of-roundness, deviations along the meridian, and bulges are caused by the manufacturing process of ellipsoidal heads, especially large-scale ellipsoidal heads assembled from formed segments. The shape imperfections significantly reduce buckling pressure of ellipsoidal heads, and thus it is essential to control shape imperfections. First, we measured the shapes of large-scale ellipsoidal heads using a 3D laser scanner that can provide the actual head shapes with more accuracy. The measured and perfect shapes were compared to determine the head shape imperfections. Based on the analysis results of head shape imperfections obtained from 3D laser scanning, a formula for characterizing shape imperfection of deviation along the meridian at head knuckle was proposed. Second, we established finite element models of ellipsoidal heads containing deviation along the meridian characterized by the above formula. Buckling of head models containing shape imperfections was simulated using the arc-length method, taking into account the effect of material and geometric nonlinearities. Third, we investigated the effects of shape imperfection magnitude and head wall thickness on buckling pressure of ellipsoidal heads under internal pressure. On this basis, limitation for the maximum allowable imperfection magnitude were determined. Finally, we proposed a new step-by-step procedure for shape imperfection control in buckling of ellipsoidal heads using a 3D laser scanner.