bluuebunny/crossref_metadata_2025 huggingface dataset:
In situ effective pumping speed measurements as a tool for non-evaporable getter activation and saturation monitoring
Authors: Kondrashev S. , Beebe E. , Coe B. , Rodowicz T.
Published: May 2024

We have developed method of in situ effective pumping speed measurements based on injecting finite gas pulse into a vacuum volume and subsequent recording of pressure response using a Residual Gas Analyzer (RGA). The pressure burst caused by injected gas pulse falls exponentially in time and the exponential coefficient of such pressure decay is proportional to total effective pumping speed of all vacuum pumps acting on vacuum chamber volume. The effective pumping speed can be extracted from the dependence of injected gas species pressure vs time recorded by an RGA. Non-Evaporable Getters (NEGs) are widely used in multiple ultra and extremely high vacuum devices and applications during the last several decades. Areas of NEG applications were recently expanded into vacuum devices with relatively high-pressure levels (up to 10−7 Torr) by the invention of high capacity ZAO NEG which can be operated at elevated temperatures. The intrinsic property of all NEG-based vacuum pumps is the reduction of their pumping speed, called “NEG saturation”, after an extended period of operation. Typical time interval for such process can span from about a month and up to a few years depending on NEG type, vacuum level of NEG pump operation, and residual gas content. After that, the NEG pump will require a re-activation cycle to restore its pumping speed close to the initial value. For many applications it is difficult to realize what is the current pumping speed of NEG pump is and when the pump should be re-activated. A method for in situ effective pumping speed measurements developed in this study can be used as a tool for NEG-based pump activation and saturation monitoring. Application of such an approach to monitor pumping status of NEG pumps was utilized and will be continually used at Extended EBIS which was recently developed and commissioned for Relativistic Heavy Ion Collider (RHIC) and future Electron Ion Collider (EIC). The results obtained during commissioning are presented and discussed.
A Long-life Laser Ion Source Using a Reproducible Solidified Gas Target
Authors: Hasegawa J , Inoue Y , Matsubara N , Tamura J , Takahashi K , Horioka K , Takayama K
Published: May 2024

A novel laser ion source using a reproducible cryogenic target has been developed for next-generation heavy-ion cancer therapy accelerators. A solid thin layer of butane formed on a cylindrical cold head cooled with liquid nitrogen is ablated by a frequency-doubled Nd:YAG laser to generate high-charged carbon ions. The properties and reproducibility of the carbon plasmas produced under various conditions are investigated.
H− Ion Source RF Plasma Testing with 13 MHz and 27 MHz at the Spallation Neutron Source (SNS)1
Authors: Narayan A.H. , Piller C. , Vestal D.C. , Stinson C. , Han B. , Welton R. , Terszakowec G. , Andzulis V. , Kang Y.
Published: May 2024

The baseline RF-driven H− ion source configuration at the Spallation Neutron Source (SNS) facility uses a continuous wave (CW) 600 W 13 MHz RF system to ignite and maintain a low-density plasma inside the ion source vacuum chamber. After the continuous low-density 13 MHz plasma has been established, a pulsed (typical 1 ms pulse width and 60 Hz pulse repetition rate) 80 kW 2 MHz RF system is used to increase the plasma density to produce the pulsed H− ion beam. Incremental upgrades and improvements to the SNS ion source systems have resulted in the ability to reliably operate an H− ion source for SNS neutron production run cycles that can last up to four months. Conditions inside the SNS H− ion source evolve throughout a four-month run cycle due to changes in impurity levels, sputtering, and erosion. As the internal ion source conditions change during the run cycle, there can also be changes in plasma stability and the 13 MHz RF power level required to ignite the plasma. This paper presents the preliminary results of testing performed on the SNS Ion Source Test Stand (ISTS) system where we looked at plasma ignition and plasma stability using 27 MHz RF in place of the baseline 13 MHz RF system.
Design and preliminary tests of an Active Plasma Chamber for ECR Ion Sources
Authors: Odorici F. , Castro G. , Leonardi O. , Russo F. , Malferrari L. , Celona L. , D’Agostino G. , Gammino S. , Chines F. , Costanzo G. , Furini M. , Gessi C. , Guerzoni M. , Margotti A. , Michinelli R. , Siliato D.
Published: May 2024

An innovative plasma chamber for Electron Cyclotron Resonance Ion Sources (ECRIS) has been developed at INFN and will soon be installed and tested with the AISHa (Advanced Ion Source for Hadrontherapy) ion source. It consists in inserting a particular liner into the existing chamber, which allows an electrical segmentation of the internal walls of the chamber. The purpose of this system is to reduce the ion losses induced by the anisotropic diffusion mechanism, to improve the plasma confinement and thus to increase the overall performance of the ion source. In fact, in ECRIS plasmas, electrons mostly diffuse along magnetic field lines while ions mostly leak across the same lines. In particular, the inner walls of the plasma chamber are covered with 30 tiles, each one polarized to a proper positive voltage. The tiles are made of Al-6082 and anodized except for the surface directly facing the plasma. The anodizing process makes each tile electrically insulated from the others and from the plasma chamber while preserving the correct operation of the cooling system. The tiles are wrapped by 2 half-cylinders made of Al-6082 acting as shells. Some tiles are equipped of a temperature sensor and machined to allow the wiring of the entire system.

In this work the results of the preliminary tests of the thermal and electrical behaviour of the active chamber and the future perspectives are presented.
Dynamic Change of the Work Function of Plasma Electrode Materials due to Hydrogen Plasma exposure
Authors: Sasao Mamiko , Broude Juan-Pablo , Cartry Gilles , Layet Jean-Marc , Nakano Haruhisa , Nishiwaki Mayuko , Wada Motoi
Published: May 2024

It has been known that the work function of plasma electrode (PE) surfaces such as Cs-covered Mo and C12A7-electride can be decreased when the surfaces are immersed in hydrogen (or deuterium) plasma. We discovered that the work function of the C12A7-electride changed right after the termination of plasma exposure with the time constant of a few minutes. This phenomenon was not observed on the surface of clean metals (Mo or Ta). By extrapolating the dependence of work function against time to determine the value at the plasma termination, the work function during plasma exposure was estimated to be 2.4 – 2.5 eV, which can be compared with the value of the electride exhibiting metallic conductivity.
Recent advancements with the H− injector performance for the Spallation Neutron Source operation and upgrade
Authors: Han Baoxi , Welton Robert , Stinson Chris , Andzulis Vic , Terszakowec Greg , Piller Chip , Narayan Amith , Peplov Vladimir , Pennisi Terry , Murray Syd , Stockli Martin , Kim Sang-Ho
Published: May 2024

The Spallation Neutron Source (SNS) located at the Oak Ridge National Laboratory is an accelerator-based, pulsed neutron facility utilized for a broad range of scientific research and industrial applications. In the past 5 years, the facility has reliably been operated at its baseline design beam power of 1.4 MW, and it is currently undertaking an upgrade to double its power to 2.8 MW. A 65-keV H− injector, which comprises an rf-driven H− ion source and an electrostatic low energy beam transport, delivers the required high-current, time-structured H− beam to the accelerator. The H− injector can reliably provide 50-60 mA beam current at 6% duty-factor (1 ms, 60 Hz) for a 3-4 month service cycle. To ensure sufficient operational margins for the SNS routine operations and ongoing upgrade requirements, the injector system has been continuously improved on a R&D test stand. This paper presents the operational status and recent advancements with the injector system performance including the enhanced ion source beam output capability up to ∼110 mA, the improved ion source plasma ignition reliability using a 27.12-MHz RF system, and the upgraded LEBT beam chopper system etc.
RF-driven H− sources of long life-time and new LEBT developed at CSNS
Authors: Chen Weidong , Li Hui , Liao Hui , Lü Yongjia , Cao Xiuxia , Liu Shengjin , Xiao Yongchuan , Chen Benzheng
Published: May 2024

An RF-driven ion source has been put into commissioning on the China Spallation Neutron Source (CSNS) accelerator since September 2021. In the last two run cycles, the ion source has operated for 310 and 323 days respectively, with an availability of almost 100%. To fully meet the requirements of the CSNS project Phase-II (CSNS-II), the beam intensity from the linac should be enhanced to above 40mA, and the transverse emittance should be minimized to suppress beam loss during acceleration and transportation. A new test bench consisting of an ion source and a LEBT has been constructed to carry out these optimization and research. The featured functions of the LEBT are associated with proton elimination and electrostatic beam chopping. This report covers the operation status and development of the RF-driven H− source and the new LEBT.
Creation and characterisation of multi-charged cerium beams at TRIUMF’s OLIS
Authors: Justus P. , Charles C. R. J. , Ames F. , Jayamanna K. , Malbrunot-Ettenauer S.
Published: May 2024

A novel 140Ce
n+ stable ion beam was developed at TRIUMF’s Off-Line Ion Source (OLIS) facility for fundamental research into (i) astrophysical processes, and (ii) forming lanthanide molecules with O2 gas and halogens. This first creation of a multi-charged 140Ce beam at OLIS is a successful chemical analog for actinide beams and molecule formation at TRIUMF’s TITAN facility for future electron dipole moment (EDM) measurements with rare radioactive thorium molecules.
The High Beam to Power Efficiency Investigation of Miniaturized Microwave Ion Source
Authors: Peng Shixiang , Ma Tenghao , Cui Bujian , Wu Wenbin , Jiang Yaoxiang , Guo Zhiyu , Chen Jiae
Published: May 2024

A miniaturized 2.45 GHz microwave ion source (MIS) with plasma chamber of ϕ30 mm × 40 mm that has the ability to produce more than 20 mA CW hydrogen ion beam with 180 W microwave power has been built at Peking University (PKU) 5 years ago1. A hibrid discharge principle has been proposed on this kind of MIS2. Recently, under the structure of this MIS, factors such as input power, pressure, magnetic field configuration and the size of plasma chamber have been investigated. Based on this research, a more compact 2.45 GHz microwave ion source with inner diameter of 24 mm has been developed. A 32.5 mA hydrogen ion beam was obtained with only 100 W microwave power.
The SPES Laser Ion Source: Time Structure and Laser Enhancement Measurements with Sm+ beam
Authors: Khwairakpam O S , Mancheva R , Au M , Bernerd C , Centofante L , Chrysalidis K , Crepieux B , Fedosseev V N , Heinke R , Marchi T , Mariotti E , Marsh B A , Monetti A , Nicolosi P , Rothe S , Scarpa D , Schuett M , Stora T , Andrighetto A , Manzolaro M
Published: May 2024

A two-step resonance photo-ionization scheme has been used to ionize samarium atoms in the SPES tantalum hot-cavity ion source. The effect of the ion load on the ion beam time structure and the laser enhancement of the ion yield has been studied at different ion source temperatures. Generally, the introduction of more positive ions (ion load) affects negatively the overall confinement of the laser ions inside the volume of the ion source. Possible enhancement of the laser ion confinement through the introduction of neutrals is observed as well. The ion load is also observed to affect the confinement in the transfer line much more than in the hot cavity. Measurement of the time structure with inverted polarity of the cavity DC heating supply confirmed the significance of the longitudinal potential for ion extraction. The laser enhancements of the ion yield are found to be sensitive to the ion load at low operating temperature of the ion source i.e. 1800°C, whereas at 2050°C and 2200°C, they are relatively stable till an ion load value of 1.2 µA.
A new proton injector based on PKU-type 2.45GHz PMECR ion source for BNCT facility
Authors: Cui Bujian , Peng Shixiang , Ma Tenghao , Wu Wenbin , Jiang Yaoxiang , Guo Zhiyu , Chen Jiaer
Published: May 2024

A first fully domestically Accelerator-based boron neutron capture therapy demonstration device(AB-BNCT) located in Yangtze River Delta region is being build recently. The project is held by “Xi’an Jiaotong University-Huzhou Neutron Science Laboratory” joint lab established by Xi’an Jiaotong University and Huzhou Industrial Group. The AB-BNCT facility requires a proton beam of 30 mA@40 keV at RFQ entrance, with its beam duty cycle between 0.5%-100%, and its normalized root mean square emittance less than 0.2 π.mm.mrad. Ion source group of Peking University (PKU) is in charge of the proton ion source and its low energy beam transportation section (LEBT). A PKU type compact permanent magnet 2.45 GHz ECR ion source (PKU-Type PMECR) and a two solenoid LEBT is under development for this purpose. So far, the PMECR ion source conditioning is complete and all parameters are better than required for this facility. The details will be presented in the present paper.
Ion source developments to supply mono & multi charged ion beams to the new NHa C400 hadrontherapy system.
Authors: Maunoury L. , Velten P. , Donzel X. , Engelen V. , Collignon G. , Sortais P. , Perrussel J. , Paliard P. , Bérard D.
Published: May 2024

Normandy Hadrontherapy (NHa) is developing, in collaboration with Ion Beam Applications (IBA), a full hadrontherapy treatment solution based on a new multiparticle cyclotron. 12C6+ and 4He2+ ions will be accelerated up to 400 MeV/u and (H2)+ up to 260 MeV/u. Three different ion sources will be carried out for each accelerated particle: the mono-charged ion source (H2)+ and low charged ion source He2+ are provided by the Polygon Physics (PP) company. The carbon ion source is under development at NHa in collaboration with IBA and PP. The (H2)+ ion source is an industrial Tubular ECR Source (TES) fitted for the needs of the NHa C400 cyclotron (30 µA of (H2)+). The He2+ ion source is a classic 10 GHz ECR type with a new concept because the complete source is set inside a vacuum chamber and it runs under 10−6 mbar of gas residual pressure. The 12C6+ ion source is also an ECR type ion source operating at 14.5 GHz frequency, its design is under progress to produce a beam providing stability and reproducibility levels compatible with clinical use. The article will present the External Injection System of the NHa C400 cyclotron hence it will focus on the experimental results obtained with the (H2)+ ion source and preliminary outputs from the He2+ ECRIS. A presentation of the multicharged ECRIS design dedicated to the 12C6+ production will be done.
Compact Monoenergetic Proton Generator in MeV Region Using NANOGAN
Authors: Yorita Tetsuhiko , Morita Yasuyuki , Takahisa Keiji , Shima Tatsushi , Kanda Hiroki , Fukuda Mitsuhiro
Published: May 2024

For simple applications, such as the calibration of a charged particle detector, a multi-MeV proton generator may be preferable to cyclotrons or electrostatic accelerators such as Van de Graaff. Thus, a compact proton generating system, consisting of 10Ghz ECR ion source NANOGAN and a deuteron target, was developed at the Research Center for Nuclear Physics at Osaka University. A 3He2+ beam was generated by the NANOGAN with the acceleration voltage of 20∼45 kV in an experiment that utilized the fusion reaction 3He + deuteron (d) → proton(p) + 4He. The monochromatic protons with energies of 14.67 MeV were successfully obtained at the atmosphere side of the target in the experimental setup, when a novel target base with a thin metal foil and Polyimide film window are used.
Research on long term tracking of centralized power EMU wheel wear and vibration performance
Authors: Guo Tao , Qu Sheng , Yang Zhenhuan
Published: May 2024

The centralized power EMU is a new type of passenger transportation equipment for ordinary-speed railways in China, which can greatly improve the efficiency of ordinary-speed railway passenger transportation and improve passenger travel conditions. This paper conducts long-term dynamic tracking experiments on this new type of railway passenger car, studying the evolution laws of wheel wear, axle box vibration, bogie frame vibration, and car body vibration during long-term service, and analyzing typical vehicle dynamics phenomena that occur in long-term tracking experiments. Various studies have shown that the vehicle can maintain good lateral stationarity throughout the entire wheel reprofile cycle, and the growth rate of equivalent conicity gradually slows down as the mileage increases; However, when the mileage after wheel reprofiling is large, harmonic vibration may occur in individual sections of the frame, leading to abnormal vibration of the control car body at 10 Hz. The vertical vibration of the axle box will significantly increase at the rail joint, and its 70 Hz vibration is transmitted to the frame through the experiment suspension, stimulating the bending mode of the crossbeam of the frame, resulting in a more obvious 70 Hz vibration in the vertical direction of the frame. The RMS of the axle box, frame, and body sleeper does not show significant changes with the rise in mileage following wheel reprofiling.
A study on robust design of cruciform torsional beam/cantilever beam
Authors: Yue Shidi , Tan Xiaolan , Li Dingyu
Published: May 2024

The electro-thermal actuator of a micro-electromechanical system (MEMS) has high power consumption and low response speed. To overcome this shortcoming, a steady state mechanism of cross torsion beam/cantilever beam is proposed in conjunction with the micro-electro-thermal actuator. Through the analysis of the structure and working principle of the cross torsion beam/cantilever beam, as well as the randomness analysis of its design variables and noise factors, the robust design is carried out, and the algorithm program of the stochastic model is written to solve the robust design model. The results show that the robust design method can not only ensure that the cantilever beam will not collapse excessively after the whole mechanism is released from the air but also ensure the robustness of the design solution when the design variables and noise factors change.
Study on the segregation effect of pyrite and brass ore particles under combined pendulum vibration
Authors: Zhang Haoqiang , Juanatas Ronaldo A. , Niguidula Jasmin D. , Cai Liu
Published: May 2024

This article uses a combined pendulum mode to study the segregation behavior of spherical particles of pyrite and brass ore with different diameters using the discrete element method. The numerical simulation program includes extensive oscillation tests on binary mixed particles of pyrite and brass ore spherical particles in different steel U-shaped oscillation grooves, different oscillation frequencies, oscillation angles, and particle sizes. The dispersion coefficient γ calculated from the Lacey mixing index M is used to characterize the segregation behavior of binary mixed particles and track the evolution of segregation. Numerical simulation shows that the oscillation frequency is 8 Hz, the oscillation amplitude is 14°, and the dispersion coefficient γ of the first group with protrusions reaches 0.8, which is about 19.4% higher than the dispersion coefficient 0.67 of the first group with light grooves. The dispersion coefficient γ of the second group with added protrusions reached 0.69, which is about 16.95% higher than the dispersion coefficient 0.59 of the second group when using a light groove. The addition of protrusions improved the particle layering effect. The oscillation amplitude is taken as 14°, and the oscillation frequencies are taken as 6Hz, 8Hz, 10Hz, and 12Hz, respectively. As the oscillation frequency increases, collisions between particles become more intense, and the dispersion coefficient γ between particles increases to a certain extent when it changes from 6Hz to 8Hz. Then, as the oscillation frequency increases, the dispersion coefficient γ decreases in severe fluctuations, and the particle stratification effect actually deteriorates. The oscillation frequency is taken as 8Hz, and the oscillation amplitude is taken as 10°, 14°, and 18°, respectively. After the oscillation amplitude increases to 14°, the dispersion coefficient γ of the particles remains basically stable, and changing the oscillation amplitude has almost no effect on the particle stratification effect. The oscillation frequency is 8Hz, and the oscillation amplitude is 14°. When adding protrusions to the steel U-shaped oscillation groove, the average relative errors of both experimental schemes are less than 1%, and the correlation coefficients are close to 1. The data points are very close to the 45° line. It indicates that the experimental data and simulation values have high consistency, and the discrete element method is feasible and reliable as a method for studying mineral particulate matter. The in-depth study of the separation and stratification behavior of ore particles under combined oscillation is of great scientific significance for the development of new combined vibration equipment.
Theoretical calculation and simulation analysis of hydraulic joint pressure loss based on fluid dynamics
Authors: Wang Nenghui , Shuai Gaopeng , Ye Jiayu , Wu Haihong , Zhu Yunyi , Wu Hai , Cheng Weiping
Published: May 2024

To study the pressure loss in the runner during the rotating transmission of the hydraulic joint, the local pressure loss of the hydraulic joint is simplified, and the theoretical estimation method of the pressure loss of the hydraulic joint is proposed. Based on the finite element software Comsol, the numerical analysis of the hydraulic joint is carried out to study the effect of the regularity of different fluid inlet and outlet angles and the width of the annular runner on the pressure loss of the runner. The results show that the relative numerical simulation result error of the theoretical calculation of fluid pressure loss is within 20%, and the theoretical calculation method proposed in this paper can guide the rapid evaluation of slip ring pressure loss. The pressure loss of the slip ring increases at first and then decreases gradually with the increase of the fluid inlet and outlet angle. When the angle of the fluid inlet and outlet is 30, the pressure loss of the hydraulic joint is the largest. The pressure loss of the hydraulic joint gradually decreases with the increase of the width coefficient of the runner. When the width coefficient increases to a certain value, the pressure loss reduction effect of the runner is weakened, and the optimal runner width is 0.8-1.2 times the design width of the equal section.
Analysis of the causes of waste heat boiler leakage in large-scale chemical plants
Authors: Du Chenyang , Cheng Lei , Lu Jianyu , Liu Chang , Li Xiaowei
Published: May 2024

A waste heat boiler is a kind of high-temperature and high-pressure heat exchanger in a large chemical plant, and its safe operation is directly related to the production efficiency and safety risk of a chemical plant. In this paper, the leakage failure analysis of a waste heat boiler in an ethylene plant is carried out, and the analysis methods such as field observation, macro observation of fracture, metallographic analysis, micro observation of fracture, phase analysis, and energy spectrum analysis are adopted respectively. The results show that the direct cause of the leakage of the waste heat boiler is the thinning of the wall thickness of the heat exchange tube caused by alkali corrosion, which leads to the overload and fracture of the heat exchange tube. The pits on the outer surface of some heat exchange tubes are caused by mechanical reasons, which are related to this leakage and closure. The corrosion failure of heat exchange tubes is widespread, which has a great influence on safety production and serious consequences. Through this comprehensive analysis, the failure mechanism is clarified, which can provide a reference for the maintenance of similar equipment. At the same time, preventive measures are put forward from the aspects of technology, structure, and detection to reduce the occurrence of similar accidents.
Design and research of oiling device for winding machine
Authors: Chen Sitao , Zheng Hongfan , Fang Dewei , Liang Zhu
Published: May 2024

Most of the existing oiling devices for winding machines rotate the first sponge layer and the second sponge layer by rotating the shaft, so as to evenly coat the oil layer on the surface of the wire body. However, dust impurities may remain on the surface of the wire body, which may lead to uneven oiling of the wire body, and it is necessary to oil the wire body again. Aiming at the above problems, this paper designs an oiling device for winding machines. The main technical feature is that the surface of the wire body is cleaned by setting a cleaning sponge, and the surface of the wire body is oiled by using the oiling sponge, so as to solve the problem of uneven oiling and influence the winding efficiency because of dust and impurities on the surface of the wire body.
Effect of tempering temperature on microstructure and mechanical properties of 4Cr13VTi steel
Authors: Pan Peng , Wang Jinnan , Yang Ming
Published: May 2024

To optimize the tempering process of 40Cr13VTi steel containing V and Ti, the effect of tempering temperature on microstructure, precipitation, and properties of 40Cr13VTi stainless steel has been studied. Optical microscope (OM), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS) were used to analyze microstructure and precipitates. Tensile, impact, and hardness testing tests were performed to test the mechanical properties of 40Cr13VTi martensitic stainless steel. The research results indicate that as the increase of tempering temperature, the carbides precipitated gradually increase, and the shape gradually changes from particle to flake, which is consistent with the direction of the original martensite flat surface, and most of them concentrate at the martensite boundary. When the tempering temperature is 350°C, 40Cr13VTi martensitic stainless steel obtains the best comprehensive properties, strength, impact toughness (IT), and hardness which are 1360 MPa, 1717 MPa, 8.5 J/cm2, and 45.1 HRC respectively.
Piston structure design and finite element analysis
Authors: Zheng Bin , Li Junbo
Published: May 2024

The working characteristics of internal combustion engines rely on the explosive combustion of fuel in the combustion chamber to drive the piston movement. This working characteristic causes the main component of the combustion chamber, the piston, to bear high thermal and mechanical loads. It has very high requirements for design, manufacturing, and material selection. The working condition of the piston will affect its safety and stability. Therefore, the finite element analysis for the piston is particularly important. Thus, this article first establishes the piston model and divides it into grids in ANSYS, adds boundary conditions, and conducts analysis. The piston thermal analysis mainly includes thermal stress and deformation analysis under thermal load. The piston’s maximal thermal stress is 170.23 MPa and the deformation of thermal expansion is 0.61585 mm. The mechanical stress and deformation analysis under mechanical load are carried out. The maximal stress is 164.91 MPa and the maximal deformation caused by the mechanical stress is 0.24916 mm. Finally, the coupling analysis of thermal and mechanical stress is conducted. The maximal stress is 251.74 MPa, which is located at the outskirt margin of the piston pinhole. The maximal deformation is 0.60779 mm. The simulation analysis results indicate that the method proposed in this article provides a way to design the structure of similar automotive components such as pistons.
Free vibration analysis of CNT reinforced plates using higher order shear deformation theory
Authors: Xue Ting , Qin Xiansheng , Zhang Shunqi , Wang Zhanxi , Bai Jing
Published: May 2024

With the stringent requirements of lightweight and high stiffness in space technology and spacecraft, the research on frequency characters of carbon nanotubes (CNTs) reinforced structures is particularly urgent. In this paper, based on the Reissner-Mindlin higher-order shear deformation theory (HSDT), a vibration model for a CNT functionally graded (FG) plate is developed, and influences of the reinforcements distribution form, reinforcement volume fractions, and various boundary conditions of the structure are considered in this established model. Subsequently, the model’s convergence test was presented first with a rectangular plate structure. Finally, the vibration characteristics and modal shapes of the CNT-FG plate structure are carried out by using this model.
Fractional order adaptive sliding mode control method of manipulator
Authors: Zhang Yanzhu , Ma Chunhao , Zhuang Bo , Zhang Junwei
Published: May 2024

A new controller (NAFOFTSMC) is designed and successfully applied to the manipulator system. Compared with traditional integer-order sliding mode control methods (IOSMC), the fractional order sliding mode control method (FOSMC) adopted additional degrees of freedom and, to some extent, weakens the drawback of sliding mode control chattering problem. Fractional-order adaptive rate compensation is utilized to compensate for the total disturbance set of the system. The new sliding surface reduces the derivative signals that are difficult to obtain due to external interference and other factors in the robotic arm system. It also reduces the unknown parameters for adjustment, increases the proportion term, and thus enables the system to have higher control accuracy and shorter adjustment time. While designing the controller, the stability is proved at the end of the fourth section. At the same time, this control method was compared and analyzed with IOSMC, simple FOSMC, and a Pre-improved controller (AFOFTSMC).
Analysis of cracking failure of gast iron brake disc
Authors: Wang Yue , Lian Zhen , Liu Fengguo , Jing Tong , Lou Changsheng
Published: May 2024

To investigate the causes of crack initiation and propagation in brake discs, a comprehensive analysis of surface cracks was conducted using macroscopic observation, metallographic observation, scanning electron microscopy, and microhardness testing. The results revealed that the internal structure of the brake disc material consists mainly of pearlite and a small amount of ferrite. Near the friction surface, the internal structure undergoes grain refinement and the formation of a small amount of granular pearlite, with a microhardness range of 350 ∼ 410 HV. Based on metallographic observations, it is evident that there are loose defects within the brake disc. When the brake disc is subjected to external loads and thermal stress, stress concentration occurs around these defects, initiating cracks and their outward propagation, thereby accelerating the crack propagation rate. The crack growth exhibits a combination of transgranular and intergranular characteristics. Analysis of the crack width in the brake disc reveals that the width of the radial primary cracks is approximately three times that of the micro-cracks, and the depth of the micro-cracks is relatively shallow, with a maximum depth of 4 mm. In contrast, the primary crack extends to a depth of 9 mm. This implies that the failure of the brake disc is associated with the extension and deepening of cracks.
Studying an improved recursive rough method for three-dimensional visual examination of steel plate butt welding surface quality
Authors: Zhang Yu-Xin , Zhao Yuan
Published: May 2024

An improved recursive rough algorithm is proposed to extract feature points in order to address the slow speed and poor accuracy of feature point extraction in 3D visual inspection, as well as the difficulty in meeting the requirements of efficient and quantitative analysis of welded surface quality detection. The preprocessed point cloud is sliced by section. The feature points are obtained according to the improved recursive rough algorithm. The defect evaluation is carried out to obtain the inspection conclusion of the weld appearance defect. Finally, according to the formulated weld defect evaluation process and standards, the typical weld template is selected for weld width, weld misedge and weld straightness test. Weld detection accuracy can reach 3 decimal places, the speed is 4 times the current manual detection speed. The detection results show that the system has the characteristics of high accuracy and fast speed which can replace manual detection. It also has a good application prospect.
Study on the effect of 1.4-butynediol on the performance of electroplated diamond wire saw
Authors: Dai Xiao-Nan , Zhou Xue , Dai Xiao-Qing , Sun Chang-Hong , Sun Wei-Yun , Bai Ling , Li Zheng-Xin
Published: May 2024

In response to the problems of low production efficiency and short service life of electroplated diamond wire saws used in the photovoltaic industry, in order to improve the performance of electroplated diamond wire saws, electroplating solutions with different mass fractions of 1.4-butynediol (0.1 g/L, 0.3 g/L, 0.5 g/L) were prepared by using electroplating methods. Nickel coatings were obtained through customized electroplating tanks, and electroplated diamond wire saws were prepared through electroplating processes. The effect of 1.4-butynediol content (mass fraction) in electroplating solution on the performance of diamond wire saws was studied. A scanning electron microscope was used to observe the microstructure of the coating surface and wire saw section, and the hardness, tensile strength, and wear of the coating with different concentrations of 1.4-butynediol were measured. The results show that among the three ratios, when the mass fraction of 1.4-butynediol is 0.3 g/L, the nickel coating has the best bonding with the metal matrix, the wire saw performance is the best, the coating hardness is the highest (427 MPa), and the wire saw has the least wear (0.092 g).
Research on electro-hydraulic position servo synchronous control system based on adaptive robust control
Authors: Zhang Tao , Fan Yuanxun , Qiu Haodong
Published: May 2024

A control method combining adaptive robust control with cross-coupling control is designed to address the issues of model uncertainty, nonlinear friction, and external interference in electro-hydraulic servo systems. We have established a nonlinear model of the system and designed an adaptive robust controller. Further simulation studies have shown that the control method designed in this paper has better control performance and stronger anti-interference ability than PID control and still has good control performance under continuous interference.
Research on the vibration isolation performance of a metal rubber-disc spring shock isolation device
Authors: Liu Guoqiang , Bai Hongbao , Zhang Yiqun , Zhu Danchen
Published: May 2024

In view of the fact that the vibration response of the laser-emitting telescope in the combination of artillery and light equipment cannot meet the target design requirements, this paper designs a new metal rubber-disc spring shock isolation device and conducts experimental research on its vibration isolation performance. The research is conducted from the frequency sweep test and the fixed frequency test. Through the vibration isolation performance test, it is found that the natural frequency of the metal rubber-disc spring shock isolation device is lower than that of the steel wire rope vibration isolator, and the frequency domain where vibration isolation occurs is wider, with better vibration isolation performance. In the fixed frequency test, the acceleration transfer rate of the metal rubber-disc spring composite vibration isolator is significantly better than that of the steel wire rope vibration isolator in the low-frequency range. As the excitation frequency increases, the difference between the acceleration transfer rate of the steel wire rope vibration isolator and the metal rubber-disc spring composite vibration isolator gradually shrinks, and finally converges.
Digital model reconstruction and geometric error analysis of additive manufacturing blisk enabled by 3D scanner
Authors: Lei Guoqing , Lu Lei , Bi Guangde , Zhang Lei , Sun Lining
Published: May 2024

Additive manufacturing has advantages in manufacturing blisk. However, additive manufacturing blisk can deviate in size and shape from their original digital models. In this paper, the shape of a complex shaped blisk manufactured by additive manufacturing is measured by using a 3D scanner, and the geometric errors compared to the digital model are calculated by using a column vector row index-based K-Neighborhood search algorithm. The computed range for geometric errors falls within (0.0075 mm, 6.9177 mm). Approximately 94% of the data points have errors within 3 mm. Larger geometric errors are primarily concentrated at the edges of the blades, aligning with the characteristic features of additive manufacturing processes.
Research on welding simulation for vacuum chamber test specimens
Authors: Shen Mengling , Han Zhichao , Xu Jijin , Zhu Jianjun , Liu Na , Liao Jingyu , Zhang Weidong
Published: May 2024

The vacuum chamber is an important component of nuclear fusion devices, and the deformation control of the welding process is relatively strict. In this paper, the isothermal multi-level cyclic loading tests have been conducted to explore a nonlinear mixed hardening mode, which can be used as the material input for the welding simulation. Then, welding simulation has been performed for test specimens of the vacuum chamber, and the deformation of test specimens has been obtained under different welding paths. After the first welding simulation is completed, the clamp and limiting plates have been designed based on the deformation of the test specimens. The welding simulation has been performed again with the clamp and limiting plates, in order to evaluate the rationality of the welding process and the design for the clamp and limiting plates. Finally, according to the determined welding process and design for the clamp and limiting plates, welding tests have been conducted, and the welding deformation has been measured. It is found that the difference between the measurement values of the tests and the simulation results is small, which implies that the welding simulation is reasonable.
Studying the factor limitations of AC corrosion on pipelines
Authors: Zhu Wenwei , Wang Yanfeng , Xu Chenghao , Wang Xinghua , Ni Shengbo , Cui Gan
Published: May 2024

This paper systematically summarizes the domestic and foreign standards and research results of the limit requirements that influence the severity of alternating AC corrosion. In the meantime, combined with the results of pieces and indoor simulation experiments, the limits of each factor affecting AC corrosion are proposed. The results show that using AC voltage and AC current density (ACCD)/DC current density (DCCD) ratio parameters, to evaluate the severity of AC corrosion, is not rigorous, and there are still many inconsistencies in reported results. The severity of AC corrosion can be better judged using the ACCD and CP current density (CPCD) or the CP protection potential. By comparing corrosion specifications laterally with different current densities and potential levels, the degree of different specifications, experimental trends and field operability, are analyzed. It is suggested that SY/T 0087.6-2021 can be used in engineering applications. Moreover, the relationship between these two types of current densities obtained experimentally is determined on the premise of acceptable corrosion. On this basis, the influence limits of different sizes of current densities on AC corrosion are further proposed.
Experimental study of penetration of pre-cut free surface rock materials based on orthogonal tests and response surface testing methods
Authors: Xu Futong , Lu Jingjing , Zhou Hui , Fang Haibo , Xiao Jiancheng
Published: May 2024

The parameters of the pre-cut kerf as the free surface on rock material have an important influence on the rock-breaking force of the disc cutter of TBM. The rock-breaking force of the disc cutter can be simplified as the normal penetration load of the metal indenter. In order to study the effect of the pre-cut free surface parameters on the penetration load, orthogonal experiments and response surface tests were carried out on sandstone and granite samples, and extreme deviation analysis and analysis of variance (ANOVA) were performed. The results showed that: (1) the order of priority of the factors affecting the penetration load of the disc cutter was Kerf depth > Kerf spacing > Kerf angle. (2) The fitting degree of the regression equation for the predicted values of the penetration loads of the sandstone and granite samples was R2 (Sandstone) = 0.9810 and R2 (Granite) = 0.9995, respectively, indicating that there was a good fit between the measured and predicted values of the penetration load of the two samples.
Design and application of composite lanchester damper for milling thin-walled part
Authors: Li Daojing , Xu Rui , Dong Qiuyan , Xu Yanlong
Published: May 2024

Thin-walled parts often produce chatter during mechanical processing due to their poor stiffness. Increasing damping can effectively improve the equivalent stiffness of thin-walled parts and weaken the vibration generated during the machining process. Based on the principles of fluid viscous damping and eddy current damping, this article proposes a design scheme for a composite viscous damper. It optimizes the structural parameters of the composite Lanchester damper according to the optimal damping coefficient. Finally, a composite viscous damper was manufactured, and modal tests showed that the amplitude of the first three vibration modes decreased by 83%, 90%, and 85% after installing the damper. In the milling test, the vibration amplitude of the thin-walled part decreased by the highest of 77%.
Study on metal corrosion behavior of heat-affected zone of oil pipeline
Authors: Lu Jianlei , Lv Jie , Luo Yujun , Liu Man , Guo Xing , Qi Ming
Published: May 2024

Due to the influence of welding technology, a series of non-uniform and continuous heat-affected zones formed by welding seams is the weakest link of pipeline steel. Compared with the X70 steel, the heat-affected area is in the form of coarse acicular and massive ferrite, granular bainite, and a small amount of pearlite, with weak strength and corrosion resistance. Therefore, this paper simulated the heat-affected zone of the high-strength steel welding seam by the Gleeble 3500 thermal/force simulation testing machine for two heat cycles. Taking Shengli crude oil as the experimental medium, the metal corrosion morphology of heat-affected zones at different temperatures and transmission rates during hot oil transportation was analyzed through immersion experiment and corrosion morphology characterization. The results show that the increase in temperature and flow rate will increase the overall corrosion rate of the metal in the heat-affected area. In the range of 30∼50°C, pitting corrosion was the main corrosion feature of the metal, and in the range of 50∼70°C, the corrosion morphology of the metal changed from pitting corrosion characteristics to comprehensive corrosion characteristics. In the range of the flow rate studied (1∼4 m/s), the metal in the heat-affected area was mainly the overall corrosion rate, and the metal surface showed the erosion-corrosion characteristics along the flow rate direction.
Effect of process conditions on the performance of LiNi0.815Co0.15Al0.035O2 positive electrode material powder synthesized by hydrothermal approach
Authors: Lv Guangzhe , Tong Binbin , Zhu Xingyu , Shi Weixi , Li Nuanfu
Published: May 2024

LiNi0.815Co0.15Al0.035O2 (NCA) lithium-ion battery cathode material was prepared using a hydrothermal approach. XRD and SEM analyzed the crystal parameters and powder morphology of the cathode material. The results show that the nickel cobalt precursor exhibits a petal-like morphology, and the nanoneedle primary particles are randomly distributed. Accompanied by the increase in calcination temperature and time, the peak intensity ratio of I003/I104 tends to decrease and then increase. The peak intensity ratio reached a maximum when the NCA sample calcined at 750°C for 8 h, indicating the lowest extent of Li/Ni mixing and the best electrochemical performance of the positive electrode material.
Study on high-temperature friction and wear properties of Arc Ion plating Cr coating
Authors: Li Dongdong , Lu Xudong , Li Jianpu , Chen Yu
Published: May 2024

In order to improve the high-temperature resistance and wear resistance of the D60 steel surface, arc ion plating technology is used to deposit Cr coating on the surface of D60 steel. A friction and wear testing machine is used to test the friction coefficient of D60 steel and Cr coating. Scanning electron microscope and Energy dispersive spectrometer are used to characterize the microstructure, composition, and phase composition of D60 steel and Cr coating. The research results indicate that when the temperature is 300°C and the load is 100 N, the friction coefficient of arc ion-plated Cr coating is higher than that of D60 steel. In addition, on the wear morphology, there are adherents and local peeling phenomena on the surface of the Cr coating.
A6N01S-T5 physical characterization of laser-MIG hybrid welding of aluminum alloys
Authors: Gou Weijie , Wang Lihong , Jia Qingshan , Liu Dongsheng
Published: May 2024

A 3 mm thick A6N01S-T5 aluminum alloy profile typical joint structure is used to carry out a laser-MIG hybrid welding test. The hybrid welding process parameters are optimized. The laser-MIG hybrid welding engineering adaptability is studied. The results show that the weld is well-formed and free of porosity defects under the optimum process parameters. The center of the weld is a dendritic cast organization. The region near the fusion line weld is a columnar crystal organization. The fusion zone is narrow, but there is a slight coarsening of the grain in the heat-affected zone. The hardness of the weld zone is lower than that of the parent material. The minimum hardness is located in the heat-affected zone near the fusion line. The average tensile strength of the joint under the best process parameters is 204.6 MPa, reaching 83.5% of the parent material. The fracture occurred near the fusion line, and the fracture shape showed typical plastic fracture characteristics. The bending performance of the joint was good. The optimal process parameters were universal when the pair gap was less than 1.0 mm, and the weld formation and tensile strength of the joint were good. When the pair gap increased to 1.5 mm, the optimized process parameters of the weld formation and tensile strength of the joint were still good. The results show that laser-MIG hybrid welding has good welding feasibility and engineering adaptability for typical joints in aluminum alloy bodies of high-speed trains.
Overlap renormalization group transformations for disordered systems
Authors: Bachtis Dimitrios
Published: May 2024

We establish a renormalization group approach which is implemented on the degrees of freedom defined by the overlap of two replicas to determine the critical fixed point and to extract four critical exponents for the phase transition of the three-dimensional Edwards-Anderson model. In addition, we couple the overlap order parameter to a fictitious field and introduce it within the two-replica Hamiltonian of the system to study its explicit symmetry-breaking with the renormalization group. Overlap transformations do not require a renormalization of the random couplings of a system to extract the critical exponents associated with the relevant variables of the renormalization group. We conclude by discussing the applicability of such transformations in the study of any phase transition which is fully characterized by an overlap order parameter.