bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on the Influence of Vacuum Vapor Phase Soldering Process Technology on SiP Component
Authors: Li Saipeng , Jiang Qinglei , Wang Xuyan , Li Jiutian 
Published: March 2023

Abstract
Vapor phase soldering (VPS) is used in the assembly of highly reliable electronic products for aerospace, military, and industrial area for the advantages of heat transfer coefficient, good temperature uniformity, and controllable maximum soldering temperature. VPS is usually used for PCB (Printed Circuit Board) and complex components. However, little research has been done on the application of VPS process technology on the SiP (System in Package) component in the process of solder ball or solder column package. In this work, we investigated the influence of the vacuum VPS process on the SiP component. The advantages of VPS and vacuum process were discussed and the maximum shear strength of solder joints in the vacuum process was calculated. The vacuum process has no impact on the internal structure of the SiP component.
Inverse attitude solution of manipulator based on improved quaternion
Authors: Yin Gui , Ju Hehua , Chen Feifei 
Published: March 2023

Abstract
Typically, quaternions or rotational matrices are used to establish kinematic equations and produce inverse kinematic solutions for the attitude of 6R decoupled manipulators. These approaches have certain drawbacks, such as duplicate equations and manual solution processes that cannot be eliminated automatically. In this study, we introduce the Ju-Gibbs quaternion to establish the kinematic equations, which are isomorphic to the Euler quaternion and share the same mathematical characteristics. Using this modeling method, one can create non-redundant kinematic equations wherein the number of equations equals the number of unknowns. A novel Dixon elimination method is then used to resolve the multilinear problem. Since no division operations are involved in the solution process, the solution has the advantage of being free of computation singularity issues. The experiment verifies that the proposed method can accomplish the autonomous modeling and elimination solution process of 6R manipulators with low computation complexity and high precision.
Analysis Of The Flow Pulsation Characteristics Of The Gear Pump Used in Electro-Hydrostatic Actuator
Authors: Tian Yan-quan , Zhang Yu-qiang , Han Xu , Wang Yuan-yin 
Published: March 2023

Abstract
Linear conjugate internal gear pump has low noise and a smooth flow, but the mechanism of flow pulsation, especially the experiment, is seldom studied. In this paper, the flow rate formula of instantaneous, flow pulsation rate and relative volume change of the trapped oil cavity are derived by means of theoretical calculation. The pressure fluctuation characteristics of the trapped oil chamber and flow pulsation characteristics of the pump outlet are studied by using the three-dimensional fluid dynamics finite element simulation analysis method. According to the international standard of ISO10767-1-2015, the pump outlet flow pulsation test was conducted. The flow pulsation rate of a certain type of linear conjugate internal gear pump with a displacement of 10mL/r is about 6.35% under the condition of the speed of 750r/min and outlet pressure of 7.5MPa, and the flow pulsation is small.
Influence of Single External Store on Geometrical Nonlinear Flutter of High-aspect-ratio Wings
Authors: Yu Lingfu , Yu Chunjin , Zhou Quanzhi 
Published: March 2023

Abstract
High-altitude and long-endurance UAVs, distributed electric propulsion aircraft and large passenger aircraft often use high-aspect-ratio wings, which have obvious geometric nonlinear large deformation effect, and are usually arranged with a certain number of external stores, which have an impact on their geometric nonlinear aeroelastic characteristics. Based on the “quasi-linear” hypothesis, the updated Lagrange incremental finite element method and doublet-lattice method are used to perform the geometrically nonlinear static aeroelastic analysis, and the mass, stiffness and aerodynamic matrices of large deformation are updated, and the geometrically nonlinear flutter characteristics of high-aspect-ratio wings are calculated. The influence of the position and mass of the external store on geometrical nonlinear flutter characteristics of high-aspect-ratio wing structure is investigated. Results show that the change of the position and mass of the external store causes the relative position between the elastic axis and the center of gravity of the wing, and the wing’s large deformation equilibrium state to change, resulting in differences in the stiffness characteristics of the wing and the natural vibration frequency of the equilibrium state, thus affecting the wing flutter characteristics. When a single external store is installed near the wing root, changing the mass and direction of the store has no significant effect on the geometric nonlinear flutter characteristics of the wing. The improvement of wing flutter speed is most obvious when the hanging point is moved to the leading edge of the wing near 0.65 times the wingspan.
Durability Analysis of Wind Turbine Blade Coating under Random Aeolian Sand
Authors: Liu Guangyou 
Published: March 2023

Abstract
Wind turbine has a poor working environment and suffered from Aeolian sand and rain for a long time, which results in serious damage to blade coating and greatly affects the later maintenance, the safe and stable operation of wind turbine. In this regard, this paper intends to use numerical simulation method to simulate the erosion process of blade coating under random Aeolian sand, and then study its durability in Aeolian environment. Taking Inner Mongolia as an example, the Weibull distribution wind speed model is established by using the measured wind speed data, and then the dynamic pressure, the impact load and the stress response of blade coating are obtained by FSI (Fluid Structure Interaction) analysis, finally, the fatigue life of blade coating is analyzed by nCode (nCode software). The results show that the dynamic pressure, the impact load and the stress response of blade coating is between20-140 Pa, 0.4-7.9 N and 0.4-2.79 MPa respectively. The maximum damage of blade coating is located near the leading edge of blade tip and its side, and the fatigue life of blade coating is 2.0×108 s.
Analysis of Micro-Electric Vehicle with Super Capacitor/Battery Hybrid Energy Storage System
Authors: Qi Jiyan , Su Ming 
Published: March 2023

Abstract
For the self-developed micro-electric vehicle (MEV), the supercapacitor/battery hybrid energy storage system (HESS) parameters were matched by analyzing the vehicle dynamic and economic constraints. The power distribution of HESS was realized by the fuzzy control strategy, and the entire vehicle model was also built to simulate the dynamic performance. The LCC model of MEV was established based on the comprehensive research of the life cycle cost (LCC). Quantitative comparisons and simulation results show that the micro electric vehicle with supercapacitor/battery HESS has great advantages in dynamic and economy. In the future, with the maturity and popularization of related technologies, the supercapacitor/battery HESS will have a huge preponderance.
Launch Dynamics Analysis of a Grenade Machine Gun with High Muzzle Velocity Based on the Soft Recoil Technology
Authors: Song Jie , Si Peng , Liao Zhenqiang , Qiu Ming 
Published: March 2023

Abstract
To study the dynamic performance of a grenade machine gun system with soft recoil technology and analyze the floating mechanism parameters affecting the firing dispersion, a rigid-flexible coupling multi-body dynamics model was established. A twenty-round firing process of the grenade machine gun system was simulated and analyzed. The firing dispersion of the grenade machine gun system was obtained based on the external ballistics model, and the simulation model was validated by comparing the numerical results with the experimental data. The effects of the floating mechanism parameters on the cradle force, the projectile dispersion, and the firing dispersion sparsity were discussed. The results show that the projectile dispersion of the GMG system is well predicted by the simulation model, and the floating parameters that are matched reasonably could improve the firing dispersion and reduce the gun recoil force.
Thermal Elastohydrodynamic Lubrication Analysis for Rolling Cone Enveloping End Face Worm Drive
Authors: Huang Geng , Liu Huan 
Published: March 2023

Abstract
To explore the thermal elastohydrodynamic lubrication performance of rolling cone enveloping end face worm drive, the mathematical model of thermal elastohydrodynamic lubrication is established based on the meshing theory of rolling cone enveloping end face worm drive and elastohydrodynamic lubrication theory. With the help of the numerical analysis software MATLAB, the thermal elastohydrodynamic lubrication performance under smooth conditions is selectively analyzed by the multigrid method. Besides, the effects of throat coefficient, cone apex radius and half cone angle of the rolling cone on thermal elastohydrodynamic lubrication performance are analyzed at the meshing out of the transmission pair. The results show that the thermal elastohydrodynamic lubrication film thickness at meshing out of the worm gear is the smallest; the oil film thickness, oil film pressure and oil film temperature are reduced from meshing in to meshing out. The oil film temperature at the interlayer is the largest. The oil film temperature at the end face worm surface is the smallest. The small half-cone angle of the cone apex radius and larger throat coefficient and cone apex radius may achieve better thermal elastohydrodynamic lubrication performance of rolling cone enveloping end face worm drive.
Study on the Influence of Process Parameters on Machining Force in Turning ADI by Response Surface Methodology
Authors: Zhao Lidong , Li Baodong 
Published: March 2023

Abstract
ADI (austempered ductile iron) has the unique advantages of high toughness and wear resistance, but it is a kind of difficult-to-machine material because of the larger machining force and high machining temperature in machining. In this paper, the influence of process parameters on the machining force is studied by turning test, and the quadratic response surface regression model of machining force is established. The results show that the primary machining force (Fx
) decreases when cutting-speed v increases, which is due to the softening of the cutting layer of the ADI when feed-rate f increases, and the strength and hardness decrease accordingly. When the feed-rate f and cutting-depth a
p increase, the Fx
increases rapidly, because the contact area of the cutter and workpiece in the effective cutting area becomes larger, and then the deformation and friction increase, leading to rapid increase of the Fx
.
Design and Implementation of Automatic Switching Exhaust Method and Air Intake Method Bell Prover Gas Calibration Facility
Authors: YongWan  , PengTian  
Published: March 2023

Abstract
As the classical bell prover gas calibration facility has the feature that is exhaust method or air intake method alone, in this paper, a new automatic bell prover gas calibration facility that combines the exhaust method and air intake method is designed. Firstly, the flowmeter, pipelines, and other related pipe fittings are mounted in advance. Then, through the system software, control on-off valves condition to switch different pipelines direction and select expected items. Lastly, the system collects the experimental dates to realize the exhaust method and air intake method altogether automatically. The newly designed facility doesn’t need to change lines manually which is time-consuming and laborious, and the calibration results are accurate and reliable as well. At the same time, the new facility which can be reconstructed from the original facility has a compact structure and small occupancy space, and it is easy to implement and has good practical and promotional value.
Optimal Design of Orthogonal Test for Resistance Spot Welding
Authors: Yuan Bo , Liu Yan , Zhang Wenqi , Tian Zhen , Zhao Shan , Feng Wenxiong 
Published: March 2023

Abstract
The optimal parameters of the resistance spot welding process are discussed, combined with the development and practice of the automobile manufacturing industry. The value, significance, and basic theory of the resistance spot welding process orthogonal test are summarized, and the importance of the orthogonal test is recognized. Then summarize the orthogonal test specimen and equipment preparation, test design, and finally analyze the orthogonal test to conclude that the optimal parameters of the resistance spot welding process are optimized, that is, the welding time is 9cyc, the electrode pressure is 1600N, and the optimal welding current is It is 11.5kA, which provides a reference for future manufacturing.
Study on the composition of a four-dimensional track display platform for aircraft based on an open-source GIS platform
Authors: Zhao Haifeng , Hou Yan , Zheng Ruikang , Zhang Jiarui 
Published: March 2023

Abstract
As one of the cores of the new-generation civil aviation transportation system, China’s new-generation air traffic management system (CNGATM) includes various contents, such as track-based operation (TBO), which has attracted more and more scholars’ attention. Traffic management for all these periods is based on the aircraft’s four-dimensional (4D) trajectory. Based on the BADA database, this paper establishes a track simulation model, obtains the flight track through simulation experiments, and analyzes the characteristics of the track. Combined with the flight dynamics model, through the study of the four-dimensional (4D) trajectory of the aircraft, the uncertainty of the aircraft path is significantly reduced, and the utilization and safety of airspace and airport resources are improved.
Steering knuckle lightweight research for additive manufacturing
Authors: Liu Lirong , Li Jinzhe , Tian Chunlin 
Published: March 2023

Abstract
As an important part of the automotive suspension system, the quality of the steering knuckle directly affects the power and safety of the whole vehicle. The lightweight of the steering knuckle is an important way to reduce the weight of the car. This paper focused on the steering knuckle of a car. Firstly, the maximum knuckle model was built according to the place of the joints (hard points). Then, the knuckle’s force in extreme conditions was analyzed by finite element methods. The result was used as the optimization boundary condition to topology optimize the part and we can get the optimized model. Finally, the model was rebuilt and analyzed again. The analysis results verify that the new structure of steering knuckles is rational.
Application of fractional controller in longitudinal control of aircraft
Authors: Liang Renjie , Liu Panling , Liu Miao 
Published: March 2023

Abstract
With the continuous development of many engineering applications, sometimes, integer order controllers can not meet the requirements of the index. Because of the progress of computer simulation and mathematical theory, fractional control theory comes into being. Given the fractional control theory, this paper first introduces the fractional controller’s theoretical basis and description form and then proposes a fractional controller. The reinforcement of the fractional controller is analyzed in the frequency domain direction, and the fractional controller is applied to the pitch angle control of the aircraft pitch channel. The simulation results show that in the pitch angle control on the longitudinal channel of the aircraft, the proposed controller in the longitudinal control loop makes the aircraft’s pitch angle control significantly improved in control accuracy, dynamic process, and steady process compared with the traditional controller.
Research on the Calibration Method of Laser Arch Measuring Instrument
Authors: Cheng Pengli 
Published: March 2023

Abstract
In view of the inconvenience caused by the lack of relevant calibration methods for the laser arch measuring instrument, this paper obtains the main components of the error based on the analysis of the principle of the arch measuring instrument, proposes the calibration methods for each error, and carries out experimental verification. The results show that the error is mainly angle error and distance error. The influence of angle error on the results decreases with the increase of the angle. According to the influence of ranging error and angle error in practical use, the methods of measuring the ranging error of the arch measuring instrument with a standard steel tape and measuring its vertical error and angle error with a movable vertical lifting two-dimensional platform are designed. The experimental results show that the calibration method is feasible.
Research and Exploration of Terahertz Feeder Manufacturing Technology Based on Micro-precision Machining
Authors: Wang Renche , Lv Hui , Zhai Jiamin , Shen Tao 
Published: March 2023

Abstract
With the development of radar towards high frequency, the demand for terahertz waveguides and other devices is gradually increasing. But it is difficult to prepare such high-precision micro-devices by conventional processing methods. This paper summarizes several micromachining methods commonly used in terahertz feeder devices. On this basis, according to the development requirements of a certain type of terahertz waveguide with the characteristic of single-input-four-output, an experimental exploration is carried out. In the development process, the methods of precision NC machining and micro electroforming are comprehensively applied. which breaks through the difficulties of reliable transfer of surface coating and efficient dissolution of micro mold. The sample that meets dimensional accuracy and microwave performance was successfully prepared. The scheme has a reasonable process setting and can promote the engineering application of terahertz waveguide devices.
Agile Micro-nano Satellite Attitude Estimation with Lost Measurements
Authors: Chen Yajing , Meng Tao , Jin Zhonghe 
Published: March 2023

Abstract
Aiming at the problem of lost measurement in attitude determination process of the agile micro-nano satellite, a novel algorithm is proposed employing the Bernoulli process to describe the loss process. Firstly,the model of gyro and star sensors as well as the satellite attitude estimation system simplified with gyro is given. Since the missing observations, the modified EKF algorithm is derived by combining a Bernoulli random variable and a real-time measurement noise correction algorithm. Then the convergence of the improved algorihtm is analyzed, and the bottom boundary condition for the observation arrival rate is presented. Finally, the improved method is compared with the conventional one through digital simulation, and the experimental results show that the preciseness of the privious one is one or two orders improved compared with the latter.
Research on TTT Curve of Alloy structural Steel based on Machine Learning
Authors: Gao Zhiyu , Fan Xianjin , Xia Tian , Xue Weihua , Gao Sida 
Published: March 2023

Abstract
Austenite isothermal transformation curve (IT) of steel, also known as time-temperature-transformation curve (TTT) is an very important basic data for the heat treatment process design of steel. Traditionally, obtaining TTT information on metal mainly depends on experiments, so there are problems such as data dispersion, large errors, and inconvenient access in use. Using artificial intelligence and machine learning technology, the TTT curve of steel can be predicted with limited experimental data. Taking the authoritative data collected as training samples, the TTT curve of alloy structural steel was predicted based on a variety of machine learning algorithms.. Alloying element category, austenitizing temperature, phase transformation time are taken as input characteristics, and 10 kinds of transformation characteristics are taken as output targets. Correlation coefficient (R), and error analysis (RMSE, MAE) are used to evaluate and finalize the model, and the best algorithm is selected to form a combined-machine-learning algorithm (CML), and predict the TTT curve. Take the application of CML multi-model prediction method in 40Cr, 38CrMoAl, 35SiMn, and 20Mn2, and the predicted results reflect that the CML model has high prediction ability and good generalization.
Research on Mechanical Properties of Winding Axial Bending Under Unbalance of Transformer Pad
Authors: Zhu Linghui , Wang Ping , Gao Shuguo , Geng Jianghai , Tian Yuan 
Published: March 2023

Abstract
To improve the study on the influence of transformer windings and pad support on transformer short-circuit resistance, the calculation method of wire bending elastic modulus is analyzed, and the sample test is carried out: The influences of the unbalance of the two ends of the wire between the number of wires wound and the span of adjacent pads on the force-deflection curve, the bending force at the selected deflection, and the elastic modulus of bending were analyzed. The results showed that: Increasing the number of wires and decreasing the height difference of adjacent pads can improve the bending force and bending elastic modulus of wires, the axial stability, and short-circuit resistance of transformer windings. When the height of the adjacent pad is not balanced, the axial force can increase the compression degree between the pad and the wire, and reduce the span of the wire. Under the action of force, the wire yields twice, which further reduces the bending force and elastic modulus of the wire. This research can provide test data support for improving the installation of transformer winding pads and theoretical evaluation of short-circuit tolerance.
Voltage Sag Recognition Based on CM-eCNN Model For Few-Shot Learning
Authors: Peng X F 
Published: March 2023

Abstract
Voltage sag is a serious problem in power systems. To reduce voltage sag, it is necessary to identify and classify voltage sag sources. However, due to insufficient voltage sag data, our paper designs a CM-eCNN model through few-shot learning. Firstly, this paper introduces the CM-eCNN model and studies how to improve the extraction efficiency of the constellation model to feature map through the attention mechanism. Then, it introduces the training method of few-shot learning. Finally, our model training with few-shot learning has better performance than other models, which proves effectiveness of the model.
Construction and Simulation Analysis of A New Transformer Noise Prediction Model
Authors: Han Xue , Chen Tengfei , Yang Guang , Li Huiqi , Song Wenle , Wang Lei 
Published: March 2023

Abstract
In recent years, more and more attention has been paid to the environmental impact of substation operation noise. Therefore, a suitable noise prediction model is needed to evaluate the noise impact. The noise in the substation mainly comes from the main transformer. The predictions of the main transformer noise model in the existing technical specifications often do not correspond to the actual situation. Therefore, based on the theory of planar Nearfield Acoustical Holography (NAH) equivalent source approach, a new transformer noise prediction model called the main transformer noise model of the directional dot-matrix equivalent source is established. Using this model, a typical 500 kV substation is simulated in Cadna/A, and the results are compared with the simulation values and measured data of the existing standard main trans-former noise model. The comparison shows that the new prediction model can accurately predict the noise value of the substation, and the error is less than 2 dB(A).