Table of Content

25 January 2024, Volume 35 Issue 01

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Research Progresses of Superhydrophobic Surface Processing Technology and Abrasion Resistance

HUANG Yun, HUANG Jianchao, XIAO Guijian, LIU Shuai, LIN Ouchuan, LIU Zhenyang

2024, 35(01):  2-26.  DOI: 10.3969/j.issn.1004-132X.2024.01.001

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The abrasion resistance of currently prepared superhydrophobic surfaces is generally poor, which limite the applications in various fields. Studied results found that micro-nano structure and low surface energy were the key factors to achieve superhydrophobic properties. Firstly, based on the mechanism of superhydrophobic surface, the superhydrophobic surface texture was summarized, aiming to solve the wear-prone challenge of micro-nano structures by optimizing the surface texture. Secondly, the superhydrophobic surface processing technology was summarized, and measures to reduce surface energy were analyzed in terms of cost and efficiency which might provide ideas for expanding the superhydrophobic surface processing system. Then, the means of analyzing the abrasion resistance of superhydrophobic surfaces were concluded in detail and the methods of improving the abrasion resistance of superhydrophobic surfaces were described. Finally, the future development prospects of abrasion resistant superhydrophobic surfaces was prospected, with a view to promote the large-scale applications of superhydrophobic surfaces in engineering.

Matching Design of Distributed Propulsion Systems for Hydrogen-Lithium Batteries Powered Commuter Aircrafts

WANG Yu, WU Tingjia, LI Xiang, YU Xiongqing,

2024, 35(01):  27-35.  DOI: 10.3969/j.issn.1004-132X.2024.01.002

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Aiming at the overall design parameters and mission profile requirements of commuter aircrafts, according to the hydrogen-lithium propulsion system architecture scheme, the propulsion system parameter matching method and energy dynamic balance management strategy were proposed. A 19-seat commuter aircraft was used to select and manage the power plant and reserve energy. According to the selected distributed aerodynamic layout scheme, then the effects of propeller rotation directions on aircraft aerodynamic characteristics were analyzed with full factorial design of experiments, and the optimum propeller rotation direction configuration for aircraft cruise states was obtained.

Design of 3K Planetary Gear Reducers with No Backlash

WANG Weijun, YANG Guilin, DU Qinghao, CHEN Qingying,

2024, 35(01):  36-44,55.  DOI: 10.3969/j.issn.1004-132X.2024.01.003

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Due to the presence of clearances in the gearing of 3K planetary gear reducers， transmission clearances were introduced into the transmission chain， resulting in a decrease in transmission accuracy and causing impacts during driving direction changes. By utilizing the characteristics that the carrier did not participate in torque transmission in 3K planetary gear transmission， a flexible planetary carrier was innovatively proposed to eliminate clearances of 3K planetary gear reducers， and the effectiveness of the proposed clearance elimination mechanisms was verified through simulation analysis. Gear matching and efficiency optimization were performed to achieve high forward and backward driving efficiency. Through the development of a prototype and testing of transmission accuracy， hysteresis characteristics， sinusoidal response error， transmission efficiency， and reverse starting torque， the effectiveness of the proposed flexible planetary carrier in eliminating clearances， transmission accuracy improvement， transmission efficiency and reverse transmission performance promoting was verified. 

Study on Vibration and Fatigue of Distributed Connection Structures of Reusable Aircrafts

SHEN Minmin, SHI Rui, GUO Pengfei, YANG Yang, YANG Xiaodong, YANG Jihou

2024, 35(01):  45-55.  DOI: 10.3969/j.issn.1004-132X.2024.01.004

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Accurate calculation of the vibration characteristics and fatigue life of the distributed connection structures between reusable spacecraft and engines was crucial for ensuring the safe operations of aerospace transportation systems. Focusing on the distributed connection structures, the feasibility of experimental validation for finite element simulation methods was demonstrated. The vibration characteristics of the distributed connection structures were explored in both of the time and frequency domains, and the fatigue lives of the structures were calculated under different operating conditions. The findings reveal a commendable concordance between the finite element results of the hysteresis curve for the connection structures and experimental observations. Under cyclic loading at different excitation frequencies, the connection bolts manifest stress increments or decrements, indicative of fatigue effects. The distributed connection structures elicit significantly heightened responses at the 1st and 5th natural frequencies. Decreasing the excitation magnitude substantially augments the fatigue lives of the connection structures, and an escalation in bolt pre-tightening forces is found to enhance fatigue lives as well. However, an increase in excitation frequency only marginally diminishes the operational lifespans, while the cyclic lifespans persist within the same order of magnitude. Furthermore, following the introduction to thermal and creep effects, the distributed connection structures may withstand a maximum of only five thermal cycling loads.

Low-speed Dead Zone Adaptive Compensation Method for Drive Units of Supernumerary Robotic Limbs

CHEN Zhongyuan, CHEN Ke, LIU Hao, OUYANG Xiaoping,

2024, 35(01):  56-66.  DOI: 10.3969/j.issn.1004-132X.2024.01.005

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To improve the control accuracy of high power density drive units in supernumerary robotic limbs, a low-speed dead zone adaptive compensation method was proposed. Firstly, the drive unit model was established based on the least square system identification and damping identification methods. Then, a computed torque control method for the drive units was proposed. Finally, an adaptive compensation method for the low-speed dead zone of the drive units was proposed and verified. The experimental results show that compared with the traditional PID control method, the maximum angle tracking errors of the drive units are reduced by about 53% and the average angle tracking errors are reduced by about 38% after the computed torque control method is utilized. Based on the computed torque control method, the maximum angle tracking errors of the drive units are reduced by about 45% and the average angle tracking errors are reduced by about 60% after the low-speed dead zone adaptive compensation method is adopted. The control accuracy of the drive units is significantly improved.

Research on Thermo-mechanical Fatigue Life Prediction Model of Ni-base Superalloy

CUI Haitao, QIAN Chunhua

2024, 35(01):  67-73,82.  DOI: 10.3969/j.issn.1004-132X.2024.01.006

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In phase TMF tests on nickel-based high-temperature alloy GH4169, a commonly used material for engine hot end components, under conditions of 200450 ℃ and 400650 ℃ is conducted. Considering the micro damage strain energy of polycrystalline materials in the elastic stages under the condition of TMF, a TMF life prediction model suitable for polycrystalline materials was proposed, model parameters were determined by combining the TMF test data. Three superalloys, GH4169, IN718, DD8, were used to evaluate the TMF life prediction ability of this model. The prediction accuracy of the life model is higher than that of the Manson-Coffin model and Ostergen model commonly used for TMF life prediction.

Calculation Method of Time-varying Meshing Stiffness of Small Module Gear Transmissions

HU Bo, AN Jinyun, YIN Lairong, ZHOU Changjiang

2024, 35(01):  74-82.  DOI: 10.3969/j.issn.1004-132X.2024.01.007

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Due to the small center distance, the dynamic performance of small modulus gear transmissions was very sensitive to the center distance errors. In addition, the intermediate gears were often designed to rotate at high speed on the fixed shaft, and there were clearances between the gear center hole and the shaft. Therefore, the calculation model of the gear mesh characteristic parameters and time-varying mesh stiffness under the influences of the center distance errors and the shaft hole fit clearances was established, and the influence laws of the two factors mentioned on the mesh stiffness were investigated. The results show that the center distance errors will change the contact degree and meshing stiffness of the gear pairs. The shaft hole clearance causes the actual center distance to fluctuate periodically around the theoretical center distance, which leads to the coexistence of the strengthening and weakening regions of the meshing stiffness in the whole cycle. The influences of center distance errors and shaft hole fit clearances both superimposed and weakened each other in different angle ranges, resulting in the difference in meshing stiffness of each gear tooth, and the risk of inducing greater vibration and different noise.

A Structural Reliability Calculation Method Based on Adaptive Kriging Ensemble Model

GAO Jin, CUI Haibing, FAN Tao, LI Ang, DU Zunfeng

2024, 35(01):  83-92.  DOI: 10.3969/j.issn.1004-132X.2024.01.008

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 The reliability analysis results of complex structures based on the Kriging model were highly dependent on the fitting accuracy of the Kriging model. In the constructing processes of the Kriging model, the selection of different correlation and regression functions affected the accuracy of the model. In order to solve the impacts of model uncertainty on the reliability analysis results, while considering computational efficiency and accuracy, based on the Kriging model and Monte Carlo simulation(MCS) method, a structural reliability calculation method combining adaptive ensemble strategy and active learning function was proposed. Considering the modeling uncertainty of Kriging models, combined with multiple Kriging models, this methed constructed an active learning function that comprehensively considered sample point contribution and sample point distance. The ensemble Kriging model was iteratively updated through the active learning function until the convergence conditions were satisfied. Finally the structural reliability analysis was carried out by the constructed ensemble Kriging model and MCS method. The validity of the proposed method was verified by numerical and engineering examples, and the results show that the proposed method is more robust than other major methods, and the computational efficiency is higher while ensuring the computational accuracy.

Research on Curve Passing of Large Axle-load Diesel Locomotive with Radial Bogie

WANG Bo, LUO Shihui, MA Weihua, WANG Chen, QU Tianwei, LEI Cheng

2024, 35(01):  93-101,143.  DOI: 10.3969/j.issn.1004-132X.2024.01.009

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To investigate the feasibility of a radial bogie for 33 t axle-load diesel locomotives, a radial bogie scheme for large-axle load diesel locomotive was designed based on the concept, structure, and principle of the radial bogie. A dynamics model was constructed in multi-body dynamics software, and the adhesion coefficients, creepages and wear power of the leading wheelset were compared for heavy duty locomotive with the radial bogie and the conventional bogie while passing the curves. Through calculation and analysis, it is found that compared with the conventional bogie, the radial bogie may decrease the wheel slip momentum, improve the adhesion availability of locomotive when passing curves, reduce the wheel-rail wear and inconsistent wear of the left and right wheels, and decrease the frequency of wheelset repairs，which provides valuable insights for the development of large axle-load and high adhesion diesel locomotives.

Design and Experimental Verification of Unilateral Double-needle Double-thread Oscillating Stitching Trajectories

GAO Ziqiao, DONG Jiuzhi, CHEN Yunjun, JIANG Xiuming,

2024, 35(01):  102-108.  DOI: 10.3969/j.issn.1004-132X.2024.01.010

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Due to a thickness of more than 3 mm could not be sewed using the single-sided double-needle double-thread stitching head insertion mechanism, an asymmetrical 8-shaped motion trajectory was proposed and the motion trajectory of the needle insertion mechanisms was designed. Firstly, the dimensions of various components of the oscillating insertion mechanisms were determined based on the kinematic analysis of the single-sided double-needle double-thread stitching processes. Then, a mechanism model was constructed in ADAMS and a trajectory analysis was performed. Finally, stitching experiments were conducted using the prototype. The results show that the designed stitching mechanisms may increase the actual stitching thickness from less than 3 mm to 8 mm and form a stable loop during the stitching processes, confirming the reliability of the asymmetric 8-shaped stitching technique and the oscillating insertion mechanisms.

Product Architectures Evolution and Their Open Design Strategies

CHENG Xianfu, ZHANG Zhihong, WANG Chenghui, PAN Yifei

2024, 35(01):  109-124.  DOI: 10.3969/j.issn.1004-132X.2024.01.011

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Product architecture represented the arrangements and combinations of physical components. It might promote innovation of product diversity, component sharing, and meet customers personalized needs. Open design might support customers to participate in product development, and open product architecture provided platform strategy for personalized product development. To further study the theory and applications of product architecture, the concept and effect of product architecture were introduced, as well as the characteristics, association and difference between single product architecture, product family architecture and open product architecture were expounded. The evolution processes of product architecture and their internal motivation were analyzed from the aspects of architecture topology, architecture development strategy, architecture organization and management. The concept, connotation, function and mechanism of product architecture were reviewed. The dependence of customers personalized needs, product architecture and enterprises open innovation strategy were discussed, and then open design strategies of product architecture were explored.

Simulation Data-driven Migration Diagnosis Method for Guide Rail Faults in Long-term Service Elevators

XIAO Gang, GU Hairui, DONG Jinjin, WANG Qibing, LU Jiawei

2024, 35(01):  125-135.  DOI: 10.3969/j.issn.1004-132X.2024.01.012

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The existing researches of fault diagnosis of elevator guide rails has some problems, such as scarcity of horizontal vibration classification data and large difference in the distribution of training and test data sets. A simulation data-driven fault migration diagnosis method for long-term service elevator guide rails was proposed. Firstly, the horizontal dynamics model of the elevator car was constructed, different types of guide rail fault excitations as system input for simulation and rich horizontal abnormal vibration data of elevator car were obtained. Secondly, the residual network and convolutional attention mechanism were integrated to extract fault features, and the sub-domain adaptive method was used to align the conditional distribution of source domain and target domain in unsupervised scenarios. Finally, the elevator horizontal vibration data under different working conditions were used as the target domain to verify the proposed method. The experimental results show that the proposed method has high fault diagnosis accuracy in unsupervised cross-domain scenarios, which provides a reference for solving the problems of scarcity of fault data for long-term service elevators.

Robot Error Compensation Algorithm by Pseudo Target Iterative Generation

YE Bosheng, JIN Xiongcheng, LI Han, SHAO Baiyan, LI Xiaokun, LI Siao

2024, 35(01):  136-143.  DOI: 10.3969/j.issn.1004-132X.2024.01.013

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Aiming at the problems of error compensation after robot error modeling, an improved algorithm was proposed based on pseudo target iteration. This algorithm generated a new pseudo target in each iteration to correct the joint angles, thereby continuously reducing the actual errors of the robot. The pseudo target iterative algorithmic process was improved to mature the algorithm flow, 5 new and different false target generation methods were proposed, and the characteristics and applicable scenarios of each method were analyzed. An ensemble algorithm was proposed combining multiple false target generation methods to further improve the accuracy of error compensation. Using the HSR-JR612 robot to carry out simulation experiments, the simulation results show that the algorithm takes milliseconds and the compensation effectiveness is good, and the integrated algorithm may further improve the pose compensation effect. Finally, the UR10 robot and the laser tracker were used for experiments. The experimental results show that after compensation, the position errors of the robot end may be reduced to less than 0.06 mm, and the attitude errors may be reduced to less than 0.025°.

Research on Self-repairing Structure Design and Repair Performance Based on Additive Manufacturing Technology

ZHANG Zhen, GUO Ce, HU Caiji, ZHENG Wei

2024, 35(01):  144-151.  DOI: 10.3969/j.issn.1004-132X.2024.01.014

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Taking lightweight sandwich plate structures as the main research object, the self-repairing design and implementation method were studied according to the fracture failure forms of the structures. The structural samples were prepared by additive manufacturing technology, and the restoration effect of the repaired structural mechanics properties was compared and analyzed through experimental tests. The results show that the designed sandwich plate self-repairing structure has a good ability to repair cracks, and the stress resistance of the repaired structure is restoreds to 85.6% of the original structures.

Experimental Study of Dry Aerosol Jet Printing with Sheath Gas-assisted Aerodynamics Lens Focusing

SHU Xiayun, WANG Ce, CHANG Xuefeng, ZHONG Zhidong, TANG Yiquan,

2024, 35(01):  152-159.  DOI: 10.3969/j.issn.1004-132X.2024.01.015

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 To overcome the most important concerns, such as harsh storage conditions and the removal of solvents and surfactants in aerosol jet printing(AJP) technology, a nano-powder aerosol printing device with sheath gas assisted aerodynamic lens focusing was proposed, and the aerosol jet printing system was established, and the effects of printing speed, volume flow ratio of sheath gas and carrier gas on printing efficiency and line morphology were explored. The effects of laser treatment on the resistivity, microscopic morphology and oxidation degree of aerosol printing lines were analyzed by laser sintering experiments and electrochemical performance test experiments.  Experimental results show that when the printing speed is 19.20 mm/min and the volume flow ratio of sheath gas to carrier gas is 2.65, the minimum width of the printing line is 56.52 μm. After laser sintering, the nano silver powder particles in the printing lines melt and agglomerate and form filaments to bond with each other, which significantly reduces the resistivity of the aerosol printing lines.

Research Progresses and Prospects of Compression Molding of High-performance PBX

SUN Haitao, ZHAN Mei, FAN Xiaoguang, GUO Jing, HAN Chao, ZHANG Jun

2024, 35(01):  160-180.  DOI: 10.3969/j.issn.1004-132X.2024.01.016

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Pressed PBX was widely used in modern high-efficiency damage weapon warheads due to their excellent detonation and mechanics properties. The continuous changes in the future combat environment and strategic requirements were driving the development of pressed PBX towards high quality, high safety, and efficient molding and manufacturing. Thus, the current research status and problems facing the pressed PBX in molding quality and performance control, compression molding safety, and automatic manufacture were summarized herein. Firstly, the research progresses in the control of forming quality and performance of PBX was explored, including the evolution law and density inhomogeneity of explosive particle densification, damage evolution mechanism and interface performance control, residual stress detection and control. Furthermore, the compression molding safety of PBX and the current research status in digital and automatic manufacture were analyzed and discussed. Finally, based on the analysis of the current research progresses, the future development trends and challenges in the field of PBX compression molding were prospected.

Study on Critical Angle in Single-point Incremental Forming with Hydraulic Supporting

SHANG Miao, LI Yan, YANG Mingshun, ZHENG Jianming, JING Zhangshuai

2024, 35(01):  181-189.  DOI: 10.3969/j.issn.1004-132X.2024.01.017

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Uneven thickness distribution was the main reason for affecting product performance and forming quality when single-point incremental forming the thin-walled parts with complex shapes. Hydraulic supporting was introduced into the single-point incremental forming process, and a hydraulically supported single-point incremental forming process was proposed, uniform distribution of thickness was promoted by adding flexible support to the overhanging sheets. Conical parts with different wall angles were formed by single-point incremental forming of Al1060 sheets under the auxiliary supports of hydrostatic and variable pressure, the effects of hydrostatic parameters and variable pressure schemes on the thickness distribution and the critical angle of thickness uniformity were quantitatively analyzed through numerical simulations and experimental studies. The results show that the favorable hydrostatic pressure range is as 0~0.18 MPa for the critical angles of uniform thickness distribution, and the most favorable hydrostatic pressure value is as 0.17 MPa. Compared with unsupported single-point incremental forming, the hydraulically-supported single-point incremental forming process may increase the critical angle of thickness uniformity by 7°, which effectively improves the uniformity of thickness distribution and forming performance of the sheets.