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    Yaw Rate Calculation and Vehicle Stability Control Considering Tire Nonlinearity
    MIN Delei, TONG Ruting, WEI Yintao
    China Mechanical Engineering    2023, 34 (21): 2521-2530.   DOI: 10.3969/j.issn.1004-132X.2023.21.001
    Abstract1033)      PDF(pc) (7794KB)(1445)       Save
    Based on the nonlinear tire model, an accurate yaw rate calculation method was proposed to calculate the accurate yaw rate and applied to vehicle stability control. Tire nonlinearity was characterized by the brush model. The equivalent stability factor was obtained by perturbation analysis, and the accurate analytical solution of the yaw rate was obtained. The analysis of the existence of analytical solutions indicates that tire nonlinearity may impact vehicle stability. Real vehicle tests and control simulations based on vehicle models show that considering tire nonlinearity may effectively improve the calculation accuracy of the steady-state yaw rate as the target parameter, and improve the effect of vehicle stability control. 
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    A Topology Optimized Design Method for High-performance Structures with Fluid-thermal-mechanics Coupling
    LI Rongqi, YAN Tao, HE Zhicheng, MI Dong, JIANG Chao, ZHENG Jing
    China Mechanical Engineering    2024, 35 (03): 487-497.   DOI: 10.3969/j.issn.1004-132X.2024.03.011
    Abstract2048)      PDF(pc) (5000KB)(1416)       Save
    The rapid advancement of topology optimization and additive manufacturing technology provided efficient methods for designing and manufacturing high-performance complex equipment. However, current topology optimization techniques for high-performance structures only considered the design of thermal-mechanics coupling or fluid-thermal coupling, and were mostly limited to simple structures. The design under the combined effects of fluid-thermal-mechanics fields was not considered, which restricted the enhancement of structural performance. This paper tackled the challenge of designing high-performance complex structures under multi-physics fields, encompassing fluid-thermal-mechanics interactions. A topology optimization method was proposed to enhance the ability to withstand temperature of intricate structures. Firstly, the governing equations of flow field, temperature field and structural displacement field were introduced to provide a unified description of the fluid-solid materials within the computational domain. Secondly, the topology optimization model was formulated with fluid-thermal-mechanics coupling. The objective function was set to minimize the average temperature, while flow energy dissipation and structural compliance served as constraint functions. Sensitivity analysis of design variables was carried out by using a combination of the variational method and Lagrangian function. Finally, the established topology optimization model was applied to the structural design of a turbine, resulting in a structure suitable for additive manufacturing with excellent heat dissipation performance and well-balanced flow channel distribution.
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    Study on Influences of Ni Content, Nitriding Hardening Depth, and Shot Peening on Bending Fatigue Performance of 42CrMo Gears
    WU Zhongrui, CHEN Difa, WU Jizhan, YANG Yudian, LIU Huaiju
    China Mechanical Engineering    2024, 35 (03): 394-404.   DOI: 10.3969/j.issn.1004-132X.2024.03.002
    Abstract1051)      PDF(pc) (9652KB)(1096)       Save
     Single tooth bending fatigue tests were conducted on 42CrMo gears with different combinations of Ni content, nitriding hardening depth, and shot peening. The effectiveness of different process combinations on improving the bending fatigue limit of gears was investigated, providing process guidance for gear fatigue resistance manufacturing. Additionally, the contribution of surface hardness, nitriding hardening depth, surface residual stress, and Ni content to the bending fatigue limit of gears with different process combinations was analyzed using the random forest algorithm. A multiple regression model considering surface hardness, nitriding hardening depth, surface residual stress, and Ni content was established to predict the bending fatigue limit of gears. Comparing the predicted values with experimental values, the maximum error is controlled within 7.80%, providing a theoretical basis for the rapid and low-cost assessment of gear bending fatigue limit in engineering applications.
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    A High-dimensional Uncertainty Propagation Method Based on Supervised Dimension Reduction and Adaptive Kriging Modeling
    SONG Zhouzhou1, 2, ZHANG Hanyu1, 2, LIU Zhao3, ZHU Ping1, 2
    China Mechanical Engineering    2024, 35 (05): 762-769,810.   DOI: 10.3969/j.issn.1004-132X.2024.05.001
    Abstract2091)      PDF(pc) (3068KB)(1060)       Save
     High-dimensional uncertainty propagation currently faced the curse of dimensionality, which made it difficult to utilize the limited sampling resources to obtain high-precision uncertainty analysis results. To address this problem, a high-dimensional uncertainty propagation method was proposed based on supervised dimension reduction and adaptive Kriging modeling. The high-dimensional inputs were projected into the low-dimensional space using the improved sufficient dimension reduction method, and the dimensionality of the low-dimensional space was determined by using the Ladle estimator. The projection matrix was embedded into the Kriging kernel function to reduce the number of hyperparameters to be estimated and improve the modeling accuracy and efficiency. Finally, the leave-one-out cross-validation error of the projection matrix was innovatively defined and the corresponding Kriging adaptive sampling strategy was proposed, which might effectively avoid large fluctuations of model accuracy in the adaptive sampling processes. The results of numerical and engineering examples show that, compared with the existing methods, the proposed method may obtain high-precision uncertainty propagation results with fewer sample points, which may provide references for the uncertainty analysis and design of complex structures. 
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    Research Advances in Chatter of Metal Cutting Systems Involving Time Delays
    REN Yongsheng, YAO Donghui, ZHANG Jinfeng
    China Mechanical Engineering    2023, 34 (21): 2548-2567,2576.   DOI: 10.3969/j.issn.1004-132X.2023.21.004
    Abstract953)      PDF(pc) (9923KB)(983)       Save
    Metal cutting processes typically had distinct characteristics of delayed system.  Chatter phenomenon was a highly complex phenomenon which widely occured in various metal cutting processes.  Chatter prediction in cutting processes was the premise of chatter suppression.  The theoretical method for chatter prediction, in-process recognition techniques for chatter prediction, and influencing factors for metal cutting dynamics were reviewed.  Applications of machine tool structure materials were introduced.  Some problems and research directions in future were proposed. 
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    Online Diagnostic Inspection and Prediction of Product Quality in Injection Molding Intelligent Factories Based on Data Mining
    CHEN Yu, XIANG Wei, GONG Chuan
    China Mechanical Engineering    2023, 34 (14): 1749-1755.   DOI: 10.3969/j.issn.1004-132X.2023.14.012
    Abstract1101)      PDF(pc) (1793KB)(968)       Save
    The dimensional accuracy of injection products was related to the injection processing parameters, and the real-time conditions of each stage in the injection processes and the changes of real-time working conditions. A workpiece quality diagnosis model was developed herein based on data mining. The real-time data collected by high-frequency sensors such as temperature, pressure, and displacement etc. in mold were used to construct the high-dimensional time series feature set. A three-stage feature selection method was used to determine the key feature subset, which was used to train the online quality detection model based on LightGBM classifier. The future values of each features were predicted based on the CNN-LSTM temporal prediction model, and the product quality was forecasted in advance with the classifier. The results show that the average recall rate of the macros is as 89.1%, and the average recall rate of the macros is as 81.6%.
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    Digital Transformation Mode and Strategy of SMEs in China
    WANG Baicun, ZHU Kailing, XUE Yuan, BAI Jie, ZANG Jiyuan, XIE Haibo, YANG Huayong,
    China Mechanical Engineering    2023, 34 (14): 1756-1763.   DOI: 10.3969/j.issn.1004-132X.2023.14.013
    Abstract1823)      PDF(pc) (5220KB)(968)       Save
    Promoting the digital transformation of SMEs was of great significance for Chinas manufacturing industries to improve quality and increase efficiency. SMEs were facing problems in digital transformation, such as high cost, fuzzy path, talent shortage, and lacking analytical framework and reference paradigm for digital transformation. The key factors to achieve digital transformation were clarified by building an analytical framework for SMEs digital transformation herein. Through case studies, 4 basic path models of digital transformation of SMEs were summarized and proposed. Based on the above researches, targeted suggestions were proposed for SMEs digital transformation in China, so as to promote the digital and intelligent development of SMEs.
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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
    China Mechanical Engineering    2024, 35 (01): 2-26.   DOI: 10.3969/j.issn.1004-132X.2024.01.001
    Abstract1517)      PDF(pc) (50387KB)(958)       Save
    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.
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    Research Status and Development Trends of Large Wind Turbine Main Shaft Sliding Bearings
    ZHU Caichao1, ZHANG Ronghua1, SONG Chaoshen1, TAN Jianjun1, YANG Liang2
    China Mechanical Engineering    2024, 35 (10): 1711-1721.   DOI: 10.3969/j.issn.1004-132X.2024.10.001
    Abstract1514)      PDF(pc) (4422KB)(941)       Save
    The pace of large wind turbine units was accelerating, and the reliability of core components was increasingly important for wind turbine operations. Sliding bearings had the advantages of high load capacity, long life, easy maintenance, scalability and small size, and they had advantages and great potential for the reliable replacement of wind turbine main bearings key components produced at home. The problems of main shaft rolling bearings in high-power wind turbines and the advantages of using sliding bearings on the main shaft were analyzed herein. The technical methods and application status of wind turbine main shaft sliding bearing design, materials, lubrication, and experimental verification were present in detail, and the existing problems of high-power wind turbine main shaft sliding bearings and future development trends were summarized. It is expected to provide reference for the digital design and industrial development of high-power wind turbine main bearings.
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    Green Scheduling Optimization Method of Special Vehicle Body-in-White Prototype Shops Considering Equipment Preventive Maintenance
    LI Xixing, ZHOU Wenlong, TANG Hongtao, WU Rui,
    China Mechanical Engineering    2023, 34 (15): 1832-1847.   DOI: 10.3969/j.issn.1004-132X.2023.15.008
    Abstract915)      PDF(pc) (9794KB)(892)       Save
    A typical multi-objective flexible job-shop green scheduling model was established, and the makespan, total energy consumption of equipment and total smoke emission were taken into consideration. And an improved artificial bee colony algorithm was designed to solve this model. Firstly, according to the characteristics of periodic power attenuation of laser equipment, a preventive maintenance strategy that could distinguish laser equipment from ordinary mechanical equipment was proposed to reduce the makespan and the frequency of equipment failure. Then, a mutation method was designed based on equipment allocation and power selection, which could improve the local search ability of the algorithm. A selection method was introduced based on crowded distance in the follow bee search stage for population regeneration to obtain high-quality individuals. Finally, the comparison experiments were carried out based on the expanded common benchmark. Meanwhile, the effectiveness and feasibility of the model and algorithm were verified through the production case of a special vehicle body-in-white prototype workshop in an automotive equipment manufacturing enterprise. 
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    Human Factor Engineering for Human-Cyber-Physical System Collaboration in Intelligent Manufacturing
    YANG Xiaonan, FANG Haonan, LI Jianguo, XUE Qing
    China Mechanical Engineering    2023, 34 (14): 1710-1722,1740.   DOI: 10.3969/j.issn.1004-132X.2023.14.008
    Abstract1675)      PDF(pc) (5740KB)(861)       Save
    The theoretical system of intelligent manufacturing for HCPS confirmed the central position of human in the intelligent manufacturing system. Starting from the demand of human-machine collaboration in the intelligent manufacturing system, the emphases of human factors in HCIM were discussed from three levels such as behavior, intention, and cognition, based on the theory of gulf. Focusing on virtual-real fusion scenarios, multimodal human-machine interaction, cognitive quantification and other methods, the importance of human factor engineering in promoting the integration of human-computer intelligence was expounded. Finally, research direction and development suggestions of human-centered intelligent manufacturing from the implementation of HCPS intelligent manufacturing systems were put forward.
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    Patent Data Driven Product Innovation Design Based on SAO
    LIN Wenguang, LIU Xiaodong, XIAO Renbin
    China Mechanical Engineering    2023, 34 (15): 1765-1777.   DOI: 10.3969/j.issn.1004-132X.2023.15.001
    Abstract1036)      PDF(pc) (5241KB)(855)       Save
    The patent data-driven product innovation design method was proposed based on SAO using big data mining technology. Firstly, semantic dependency parsing was used to mine the SAO structure and interaction relationships among product components from patent text databases. Subsequently, a complex network knowledge model was constructed for product systems, and the constraint coefficients of components in the complex network were calculated by using structural hole theory to identify the innovative target components. Then, the semantic similarity coefficients of components were calculated using Word2Vec, and the functional similarity coefficients were calculated using SAO similarity algorithm. And the recommendation algorithm and combination matrix were integrated to achieve structural innovation, functional innovation, and functional optimization. Finally, a typical bathroom shower product was taken as an example to demonstrate the method in detail, which fully verifies the effectiveness and progressiveness of the method. 
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    Nanosecond Laser Machining of Spiral Grooves of Dry Gas Seal Rotational Ring Surfaces
    Wenqian LI, Zhanqiang LIU, Jinfu ZHAO, Bing WANG, Yukui CAI
    China Mechanical Engineering    2025, 36 (10): 2207-2214.   DOI: 10.3969/j.issn.1004-132X.2025.10.006
    Abstract650)   HTML131)    PDF(pc) (3972KB)(854)       Save

    An experimental study on the nanosecond laser processing of the spiral groove on the dry gas seal rotational ring surfaces made of GH4169 was carried out. Orthogonal tests and one-factor methods were utilized to reveal the effects of laser power, scanning speed, filling spacing and repetition frequency on the spiral groove depth and bottom roughness Ra, and to determine the appropriate combination of laser processing parameters. The results show that the greatest influence on the depth of the spiral grooves on the surfaces of GH4169 alloy is the laser power, followed by the repetition frequency and the scanning speed, and the greatest influence on the roughness of the groove bottoms is the scanning speed, followed by the repetition frequency and the scanning spacing. With the laser power of 18 W, scanning speed of 40 mm/s, fill spacing of 0.005 mm, and repetition frequency of 50 kHz, the spiral grooves on the machined rotational ring surfaces is able to meet the machining requirements of groove depth of 7 μm, and groove bottom roughness of Ra≤0.8 μm.

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    Study on Force Model and Surface Integrity of Cylindrical Grinding 18CrNiMo7-6 Steels
    WANG Dong, CHEN Lei, ZHANG Zhipeng
    China Mechanical Engineering    2024, 35 (03): 381-393.   DOI: 10.3969/j.issn.1004-132X.2024.03.001
    Abstract1099)      PDF(pc) (8185KB)(848)       Save
     In order to accurately and effectively control the influences of grinding parameters on grinding force and surface integrity, a three-stage grinding force theoretical model was established based on the plastic deformation, indentation theory and shear strain effect between abrasive particles and materials by analytical method. The brown corundum grinding wheels were selected for grinding experiments to explore the effects of grinding parameters on grinding force and the effects of grinding parameters and grinding force on surface integrity. The optimal processing parameters for cylindrical grinding were obtained through orthogonal experiments of cylindrical transverse grinding. The results show that the average prediction errors of normal and tangential grinding forces in the cylindrical grinding force model are 5.56% and 7.08%, respectively. The radial feed speed of the grinding wheel has the greatest impact on grinding force, followed by grinding width, and the influences of workpiece speed and grinding wheel particle size are relatively small. The radial feed speed and grinding width of the grinding wheel have a significant impact on residual stress, and the particle size of the grinding wheel has the greatest impact on surface roughness. As the grinding force increases, the surface roughness value continuously increases, and the residual stress firstly decreases and then increases. The maximum residual stress value along the depth direction firstly increases and then decreases. Within the parameters taken in the experiments, the distribution range of residual stress is basically 20~40 μm. The optimal combination of processing parameters is a radial feed speed of 0.15 mm/min for the grinding wheel, a workpiece speed of 120 r/min, a grinding width of 10 mm, and a grinding wheel particle size of 80.
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    Chatter Identification Method for Heavy-duty Robotic Milling Systems Based on Variational Mode Filtering and Attention Mechanism
    LIANG Zhiqiang1, 2, CHEN Sichen1, DU Yuchao1, LIU Baolong1, 2, GAO Zirui1, YUE Yi3, XIAO Yubin4, ZHENG Haoran1, QIU Tianyang1, LIU Zhibing1
    China Mechanical Engineering    2025, 36 (05): 1018-1027,1073.   DOI: 10.3969/j.issn.1004-132X.2025.05.013
    Abstract1597)      PDF(pc) (7393KB)(810)       Save
    A method was proposed for identifying chatters in heavy-duty robotic milling systems by integrating variational mode filtering with fixed parameters, envelope filtering and an attention mechanism network identification. Initially, variational mode filtering theory was applied to eliminate non-chatter signal components in the high-frequency ranges by optimally selecting a quadratic penalty. Then, to swiftly identify the current machining conditions, the envelope filtering method was employed, leveraging signal time domain distribution and the frequency domain mapping law to remove the spindle speed-related signal components in the low-frequency ranges. Subsequently, a network identification model incorporating an attention mechanism was developed to identify preprocessed multi-temporal short-term signal segments for machining condition identification, followed by verification experiments on heavy-duty robotic milling systems. Experimental analysis results demonstrate that by eliminating non-chatter signals in the high-frequency ranges and spindle speed-related components in the low-frequency ranges, the accuracy of regenerative chatter identification is significantly enhanced, achieving an identification accuracy of 98.75%. Compared with alternative identification methods, the proposed method may effectively identify regenerative chatters during heavy-duty robotic milling processes, thus offering valuable technical support for future online chatter suppression of heavy-duty robotic milling.
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    Depth of Cut Control for Thin-walled Parts in Robotic Milling Based on FLADRC
    SHI Long, ZHOU Hexiang, LI Zhoulong
    China Mechanical Engineering    2025, 36 (04): 671-680.   DOI: 10.3969/j.issn.1004-132X.2025.04.003
    Abstract2596)      PDF(pc) (8675KB)(806)       Save
    Weakly rigid large thin-walled parts had large deformations and vibrations during robotic thinning machining, which led to a degradation of the surface quality of the workpieces and difficulties in ensuring the accuracy of the remaining wall thickness. To this end, a VCM-driven follower support head was used for vibration and deformation suppression, and a FLADRC based control strategy was proposed for depth of cut of robotic milling thin-walled parts. In order to verify the effectiveness of the control strategy, the system control models were firstly established based on the MATLAB/Simulink simulation and experimental platform, and the simulation analysis was carried out, then experimental verification was carried out on the thin-walled parts robotic milling experiment platform. Both of the simulation and experimental results show that the depth-of-cut control strategy based on the follower support head may significantly suppress the vibrations and deformations during the machining processes of thin-walled parts and effectively ensure the accuracy of the remaining wall thickness. In addition, compared with the traditional fuzzy PID control, the FLADRC has a better control effectiveness and exhibits higher robustness in the presence of external disturbances.
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    Cross-domain Fault Diagnosis of Bearings Based on Discriminant Feature Extraction and Dual-domain Alignment
    DONG Shaojiang, ZHOU Cunfang, CHEN Lili, XU Xiangyang
    China Mechanical Engineering    2023, 34 (15): 1856-1863.   DOI: 10.3969/j.issn.1004-132X.2023.15.010
    Abstract1129)      PDF(pc) (4455KB)(792)       Save
     A deep transfer learning method was proposed to address the challenge of inconsistent feature distributions and difficulties in removing noise components in vibration data collected under different operating conditions for rolling bearings. The method utilized a combination of discriminative feature extraction and dual-domain alignment. Firstly, the labeled vibration signals and unlabeled vibration signals were segmented into fixed-length data sets using a data segmentation method. To mitigate the interference of noise signals in practical operating conditions, a channel attention mechanism known as SENet was employed. Additionally, a discriminative loss term was incorporated to assist the feature extractor in extracting features that exhibit discriminative properties. To handle the issue of inconsistent data feature distributions, the MMD was utilized to align the global domain distributions between the source and target domains. Furthermore, conditional adversarial learning techniques were employed to align the sub-domain distributions, resulting in dual-domain alignment. Experimental validation was conducted on two publicly available rolling bearing fault datasets collected under different operating conditions. The results show that the proposed method achieves an average recognition accuracy of over 98%. Comparative analyses with different diagnostic methods further demonstrate the effectiveness and superiority of the proposed method. 
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    Integrated Casting Triangular Beam Lightweight Improving with Multi-performance Constraints of Body Systems
    SU Yonglei, ZHANG Zhifei
    China Mechanical Engineering    2024, 35 (04): 691-699.   DOI: 10.3969/j.issn.1004-132X.2024.04.012
    Abstract1168)      PDF(pc) (6363KB)(767)       Save
     An optimization method of integrated casting structures was constructed systematically, and based on the super-element model of body system, body casting part lightweight improving with multi-performance constraints was realized. Firstly, complex body systems were reduced, the sub-system division principle and method were proposed for continuous body structure. Super-element reduction of the sub-system was conducted to ensure analysis accuracy and improve calculation efficiency, laying the foundation for rapid optimization. Secondly, performances of casting structures and body systems were considered simultaneously, the compromise programming methods were used to normalize static and dynamic sub-targets and construct the comprehensive objective function, weight coefficients of sub-targets were obtained by analytic hierarchy process(AHP), and then multi-model topology optimization was carried out to determine position distribution of reinforcements. Furthermore, designability and manufacturability were considered simultaneously, parametric definition of variable thickness drawing surface of casting structure was carried out, manufacturing constraints were applied during optimization processes, and then thickness parameter design was completed based on combined surrogate model. The results show that, under the premise of ensuring the analysis accuracy, reduced body system models improve computing efficiency greatly, and save 97.3% of computing resources. Casting triangular beam lightweight may be achieved while improving related performance by conducting structure optimization, which indicates correctness and practicability of the proposed method. 
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    Molecular Dynamics Simulation of Microscopic Crack Initiation and Extension Mechanism in 8Cr4Mo4V Bearing Steels
    Tianyu MA, Gu GONG, Hongrui CAO, Jianghai SHI, Xunkai WEI, Lijun ZHANG
    China Mechanical Engineering    2025, 36 (10): 2179-2189.   DOI: 10.3969/j.issn.1004-132X.2025.10.003
    Abstract700)   HTML101)    PDF(pc) (7456KB)(767)       Save

    To investigate the influences of cementite on the mechanics properties of the matrix and the initiation and propagation of microcracks in 8Cr4Mo4V bearing steels, molecular dynamics models were used to systematically analyze the effects of cementite's geometric parameters (such as shape, size, and position) on crack initiation and extension mechanism. And combined with cohesive force theory, the characteristics of interface crack propagation were studied. The results indicate that cementite significantly enhances the mechanics properties of the bcc-Fe matrix, with smaller cementite particles providing a more pronounced strengthening effectiveness. While the shape and position of cementite exert a relatively minor impact on overall mechanics performance, sharper inclusions accelerate crack propagation, and the position of inclusions determines the crack propagation path. Furthermore, interfaces between the bcc-Fe matrix and cementite, as well as twin boundaries with larger misorientation angles, exhibit increased resistance to crack initiation and propagation.

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    A Bionic Bouncing Robot Design and Made Inspired by Locusts
    WANG Kaidi, CHEN Suifan, TANG Wei, QIN Kecheng, LI Qipeng, YANG Zhan, LIU Yang, ZOU Jun
    China Mechanical Engineering    2023, 34 (24): 2946-2951.   DOI: 10.3969/j.issn.1004-132X.2023.24.006
    Abstract1289)      PDF(pc) (3896KB)(753)       Save
     In order to improve the mobility of small robots and increase the diversity of movement gait, a jumping robot imitating locust bouncing was designed based on the body structure and movement mechanism of locusts, and the main body was made by 3D printing. And for reproducing the locusts bouncing mechanism, a torsion spring was installed at the joints of the robot body to simulate the locusts SLP(semilunar energy storage) mechanism. When the robot met an obstacle, the torsion spring released the stored elastic potential energy and generated a ground reaction force, which realized the robots bouncing and thus crossed the obstacle. The robot might imitate the locusts jumping actions, and simulate the locusts flexibility to a certain extent. It was experimentally verified that the robot has good jumping performance, with a jumping distance of up to 100 cm and a jumping height of up to 120 cm which is about 15 times of the own length.
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    Review on Management at Mechanical Design and Manufacturing Discipline of National Natural Science Foundation of China in 2023
    YE Xin, HUANG Zhiquan, ZHANG Junhui,
    China Mechanical Engineering    2024, 35 (04): 571-579.   DOI: 10.3969/j.issn.1004-132X.2024.04.001
    Abstract854)      PDF(pc) (8141KB)(721)       Save
     The applications, evaluations, and funding of several types of projects that were classified into the talent and exploratory funding categories at mechanical design and manufacturing discipline (division Ⅱ of engineering science) of the National Natural Science Foundation of China in 2023, as well as the research progresses and findings of the executing and finished projects were reviewed. Specific measures of mechanical design and manufacturing discipline were illustrated, such as the reform of scientific fund, talent cultivation, and future research. Finally, a short prospect of the work in 2024 was introduced.
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    Research on Energy Transfer Model and Optimisation of Operating Parameters of Vibratory Rollers
    HUI Jizhuang, LUO Wei, ZHANG Zeyu, ZHANG Jun, WANG Jie
    China Mechanical Engineering    2024, 35 (03): 541-547.   DOI: 10.3969/j.issn.1004-132X.2024.03.016
    Abstract774)      PDF(pc) (1996KB)(717)       Save
     In order to improve the compaction quality of vibratory rollers, the energy transfer model of vibratory rollers and the optimisation of operating parameters were studied. Firstly, the system vibration dynamics model of “wheel-compacted material” was established based on the U-K equation, and the energy transfer model of vibratory roller was proposed in combination with energy conservation.Then, the vibration frequency and compaction speed were taken as the optimal working parameters to construct the optimisation model of road compaction quality.Finally, the feasibility and effectiveness of the proposed method were proved through case verification. The results show that: the ratio between the working frequency and the intrinsic frequency of the compacted material is kept within the range of 2~2 to avoid the effect of resonance.The initial stage of low-speed rolling, and after the material properties were stabilised, the rolling speed may be increased to ensure efficient compaction, which results in the vibration frequency in the range of 21.8~27 Hz and the compaction speed in the range of 2.36~2.91 km/s, to achieve the optimal compaction effectiveness. The proposed energy transfer model and operation parameter optimisation model lay a foundation for guaranteeing the compaction quality of vibratory rollers and provide a reference for improving the compaction quality and efficiency of vibratory rollers.
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    Inverse Kinematics Solution of Robots Based on IQPSO Algorithm
    CHEN Zhuofan, ZHOU Kun, QIN Feifei, WANG Binrui
    China Mechanical Engineering    2024, 35 (02): 293-304.   DOI: 10.3969/j.issn.1004-132X.2024.02.014
    Abstract1432)      PDF(pc) (9273KB)(708)       Save
    Aiming at the problems of singular pose, non-unique solution and low solution precision in the inverse kinematics solution processes of general robots, an improved quantum particle swarm optimization algorithm was proposed. Firstly, the robot kinematics model was established by using the D-H parameter method, and the minimum pose errors at the end of the manipulators were the main optimization goal, and the constraints of the minimum joint angle changes before and after the movement and the smooth and continuous stroke were added, and the objective function was designed. Secondly, an IQPSO algorithm was designed by using the Levy flight strategy to improve the particle update method, nonlinear dynamic adjust the shrinkage and expansion factors, and using the variable weight method to calculate the optimal average position. Then, the simulation and comparison experiments of three algorithms(IQPSO,APSO,QPSO) were carried out by simulating two different solutions of single point pose and continuous trajectory. The results show that the IQPSO algorithm has the advantages of fast convergence speed and high solution accuracy; finally, the IQPSO algorithm was used in the body of the robot arm for physical verification. The results show that the trajectory composed of interpolation points obtained by the IQPSO algorithm is continuous and smooth, which further proves the stability and feasibility of the algorithm in practical motion control.
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    Lubrication Characteristics of Gear End Face Friction Pairs of Aviation High-speed Gear Pumps
    CHEN Yuan1, XIONG Dianfeng1, LI Yuntang1, GAO Yongcao2, LI Chuancang2, WANG Bingqing1, JIN Jie1
    China Mechanical Engineering    2024, 35 (07): 1178-1187.   DOI: 10.3969/j.issn.1004-132X.2024.07.005
    Abstract857)      PDF(pc) (9034KB)(689)       Save
    Aiming at the serious wear problems of gear end face friction pairs of aviation external gear pumps, a new compound texture combining Tesla valve groove type and elliptical shape was opened on the gear end faces to improve lubrication performance. Based on hydrodynamic lubrication theory and finite element simulation calculation method, a theoretical analysis model of gear textured end face friction pair lubrication was established. Pressure distribution and velocity distribution of fluid within the end face liquid films were simulated and analyzed under conditions with and without texture, and the effects of operating and structural parameters on the openness and sealing performance of gear end faces were studied. The results show that the hydrodynamic pressure generated by the texture may make the gear end face friction pairs run non-contact, which has a positive effect on reducing friction and increasing efficiency. With the comprehensive consideration of the openness and leakage control performance of gear end face friction pairs, groove depth is as 7~9 μm, height difference is as 5~6 μm, inclination angle is as 0°~10°, and shape factor is as 0.4~0.5 are the optimal structural parameters for the texture structure.
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    Visual Detection of Subsurface Corrosions in Ferromagnetic Metal Plates Using Pulsed Eddy Current Based on Dual-sensor Differential Mechanism
    WANG Jin1, LI Yong1, SU Bingjie1, GAO Wenlong1, XIANG Yi1, 2, LIU Zhengshuai1, CHEN Zhenmao1
    China Mechanical Engineering    2025, 36 (03): 381-390.   DOI: 10.3969/j.issn.1004-132X.2025.03.001
    Abstract885)      PDF(pc) (17686KB)(688)       Save
    A pulse eddy current visual detection method was proposed based on a dual-sensor differential mechanism for subsurface corrosions in ferromagnetic metal plates. In this method, a dual-sensor differential probe was used to pick up the pulsed eddy current testing signals, and the slope of the logarithmic curve along the falling edge of the testing signals and the peak value of the normalized differential signals were extracted as signal features, which were used for visual detection of defects of different sizes. Through simulation and experimental research, the correlation laws between the proposed signal features and the sizes of defects were established, and it is verified that the dual-sensor differential probe has the advantages of reducing noise interference and improving the detection sensitivity compared with traditional single-sensor probes. In addition, a method was proposed to fuse the two signal features, and the results indicate that the defect images using fused signal features have a higher image signal-to-noise ratio. The research method proposed herein provides an effective and reliable solution for the visual detection of subsurface corrosions in ferromagnetic metal plates.
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    Identification of Position-independent Geometric Errors for Rotary Axes of Five-axis Table-tilting Machine Tools
    LIANG Xiaobing, LU Yaoan, WANG Chengyong,
    China Mechanical Engineering    2023, 34 (21): 2585-2591.   DOI: 10.3969/j.issn.1004-132X.2023.21.007
    Abstract965)      PDF(pc) (5263KB)(684)       Save
     PIGEs of rotary axes were the important factors that affected the machining accuracy of five-axis machine tools. Taking AC type five-axis table-tilting machine tools as an example, an identification method of PIGEs of rotary axes was proposed based on the differential evolution algorithm. Firstly, a mathematical model of PIGEs and length change of ball bar was established. The initial PIGEs may be identified by existing methods. Then, an optimization objective function was defined, and the PIGEs of the rotary axes were optimized as a whole by a differential evolution algorithm to improve the identification accuracy of the rotary axes PIGEs. The experimental and simulation results show that the proposed method may effectively improve the identification accuracy of the PIGEs of the rotary axes. 
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    Modeling and Experimental Research of Ground Workpiece Surface Topography after Grinding with Structured Grinding Wheels
    YI Jun, YI Tao, CHEN Bing, DENG Hui, ZHOU Wei,
    China Mechanical Engineering    2023, 34 (22): 2711-2720.   DOI: 10.3969/j.issn.1004-132X.2023.22.008
    Abstract916)      PDF(pc) (9016KB)(666)       Save
     The rough surface modeling method was employed to establish the surface topography model of a straight groove structured grinding wheel, considering the influences of structural characteristic parameters on the continuity of the grinding wheel surface through actual measurements. Based on the kinematics relationship between the grinding wheel and workpiece, as well as the trajectory equation of cutting edge, a prediction model for workpiece surface topography after grinding was formulated. Grinding experiments were conducted using both electroplating CBN and brazing CBN straight groove structured grinding wheels. The results show that relative errors between predicted Ra values and experimental ones are below 10%, while relative errors between predicted Rz values and experimental ones are below 12%, thereby validating the accuracy of the prediction model. Furthermore, the influences of various structural parameters on the surface topography of the workpiece were investigated. When the groove width of the grinding wheel remaines constant, an increase in the intermittent ratio of the grinding wheel resultes in an elevation of workpiece surface roughness. Conversely, when the intermittent ratio is held constant, variations in groove width have a minimal effect on workpiece surface roughness. Additionally, it is observed that roughness of the grinding wheel itself is a significant factor determining ground workpiece surface roughness. Among the three characteristic parameters of the grinding wheel surface topography investigated herein, it is observed that the skewness of the grinding wheel surface height exerts the most significant influence on the ground workpiece surface roughness.
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    Flexible Skin-shaped Optical Fiber Reconstruction Method for Allomorphic Aircrafts
    WANG Yuanfeng, ZHU Lianqing, HE Yanlin, ZHOU Kangpeng,
    China Mechanical Engineering    2023, 34 (15): 1873-1880.   DOI: 10.3969/j.issn.1004-132X.2023.15.012
    Abstract802)      PDF(pc) (5104KB)(659)       Save
     Large-scale deformation monitoring of allomorphic aircrafts in the flight processes was a research difficulty and hot spot in the aerospace field, and the existing methods were difficult to achieve high-precision three-dimensional deformation monitoring during the flight of the aircrafts. Aiming at this problem, a flexible skin-shaped fiber reconstruction method for a variant aircraft was proposed based on optical fiber sensing to achieve deformation monitoring during flight of the aircrafts. Based on the principle of fiber grating strain sensing, the relationship between fiber strain and curvature was derived, the conversion matrix between the local coordinate system and the global coordinate system of optical fiber sensing was established, the conversion of fiber measurement point coordinates to the global coordinate system was realized, and the three-dimensional deformation reconstruction algorithm was studied based on curve fitting according to the spatial curve fitting method. At the same time, in order to reduce the measurement errors of the fiber optic sensors, the calibration tests of the fiber optic sensors were carried out to obtain the strain sensitivity of the sensors. In order to verify the effectiveness of the proposed method, the three-dimensional deformation reconstruction of flexible skin samples under different curvatures was tested experimentally. Experimental results show that the average error of the shape reconstruction method is as 3.5% and the minimum error is less than 2.1% in the deformation ranges of 0~15.38 m-1 curvature of flexible skin samples. The proposed method has a good application prospect in aerospace and other fields. 
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    Design of Lane Keeping Assist Systems Based on Improved Preview Control Model
    LIANG Yongbin, FU Guang, LIN Zhigui, HE Zhicheng, ZHANG Jialuo, CHEN Tao
    China Mechanical Engineering    2024, 35 (03): 548-558.   DOI: 10.3969/j.issn.1004-132X.2024.03.017
    Abstract949)      PDF(pc) (8767KB)(656)       Save
    To address the issues of low robustness, consistency in vehicle manufacturing, and severe road surface interference in LKA system of torque control, a LKA system was designed based on angle control by using neural network technology, Autofix algorithm, and preview feedback control theory, through expected trajectory decision-making and following PID control algorithm. A hardware-in-the-loop simulation test platform was built to verify the effectiveness and accuracy of the design of the angle based lane protection systems through virtual simulation based on Carsim/Veristand/ MATLAB. Based on GB/T 39323—2020, CN-CAP—2021, Euro-NCAP—2022 and the testing requirements of the car retention systems based on real-road commissioning and user concern scenarios, the simulation and comparison with real-road scenarios show that the angle-controlled LKA system has better lane keeping capability, stability, adaptability and robustness than that of the torque-controlled LKA system in the same usage scenarios.
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    Effects of Forced Positioning&Clamping on Geometric and Physical Assembly Performances for Composite Structures and Collaborative Guarantee Strategies
    GUO Feiyan1, ZHANG Yongliang2, LIU Jialiang1, ZHANG Hui2
    China Mechanical Engineering    2025, 36 (04): 655-670.   DOI: 10.3969/j.issn.1004-132X.2025.04.002
    Abstract2039)      PDF(pc) (7015KB)(656)       Save
    The large-size & thin-walled aviation composite structures had low forming accuracy and huge in-plane warping deformation. The accumulation of assembly errors, unexpected geometric gaps and shape deviations were prone to occur at the joining areas. In engineering, passive reduction actions, such as applying local clamping forces was usually applied, but uneven internal stress distribution and even internal damages would be occurred, which affected the mechanical performances of the structures in service directly. Firstly, the principle of forced positioning clamping was explained, and the affection on geometric accuracy and mechanical properties of weak rigid composite parts was analyzed. Secondly, starting from the analysis of two main aspects, i.e. optimization on forced clamping process parameters before assembly, and flexible positioning force&position adjustment of fixtures during assembly, five key technologies were solved with detailed technical solutions, i.e. setting forced assembly force limits, reduction of geometric gaps, prediction of stress/damage evolution, reverse optimization of forced clamping process parameters, and precise measurement of assembly stress&damage. Then the active control of shape&force coupling and macro & micro collaborative guarantee in the clamping processes for assembly performance, could be achieved. Finally, for the composite assembly structures, from the perspective of practical engineering applications, the future working focus towards high assembly quality and efficient, and low-cost assembly goals were proposed.
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    Rolling Bearing Fault Diagnosis of Wind Turbines Based on Frequency Domain Group Sparse Model with Graph Regularization Constraints
    LI Jimeng, WANG Ze, SHI Qingxin, MENG Zong
    China Mechanical Engineering    2024, 35 (11): 1909-1919.   DOI: 10.3969/j.issn.1004-132X.2024.11.002
    Abstract1787)      PDF(pc) (11269KB)(646)       Save
    Due to effects of the non-stationary operations, noisy working environment and strong electromagnetic interference for the wind turbines, the fault impulses of rolling bearings were submerged by strong noise, and the weak features were difficult to accurately identify. To solve the above problems, a frequency domain group sparse model with graph regularization constraints was proposed, which might effectively extract fault features of rolling bearings without periodic prior knowledge. Firstly, vibration signals were converted into graph signals to construct the graph regularization constraints, and the structured information was utilized to guide the penalty strength to improve the accuracy of sparse reconstruction. Secondly, the frequency domain group sparse model with graph regularization constraints was constructed, the method was given to determine the shrinkage threshold of the in-group components, and the objective function was simplified with the proximal mapping to optimize the solution. Finally, the parameters of the model were optimized by using the constructed comprehensive index and the moth flame optimization algorithm, and rolling bearing faults were identified by the envelope spectrum analysis of the reconstructed signals in the time domain. Numerical simulation and experimental results demonstrate that the proposed method has good anti-noise performance and may effectively extract weak fault features of rolling bearings under strong noise interference.
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    Analysis and Test on Dynamic Transmission Errors of RV Reducers under Load Conditions
    XU Lixin, XIA Chen, YANG Bo
    China Mechanical Engineering    2023, 34 (18): 2143-2152.   DOI: 10.3969/j.issn.1004-132X.2023.18.001
    Abstract1054)      PDF(pc) (8485KB)(632)       Save
     For the current RV reducer transmission accuracy factory calibration value was detected under no-load conditions, it was difficult to reflect the real accuracy performance under torque loading conditions, in order to effectively reveal the dynamic transmission error characteristics of the RV reducers under the action of the load, a theoretical dynamic model of contact multi-body system of standard RV reducer with two crankshafts was proposed, which took the multi-error factors of geometry and position of key transmission parts into consideration. In order to effectively reveal the dynamic transmission error characteristics of RV reducers under load, during modeling, firstly, the parametric model of the whole reducer was designed and completed for the RV reducer transmission structure characteristics. Secondly, a detailed dynamic contact analysis method was proposed considering involute gear drive of the first stage, cycloidal-pin drive of the second stage, and multiple sets of turning-arm bearings and support bearings. Thus, the dynamic transmission error characteristics of reducer under torque load were discussed taking RV20E as the object. The results show that with the increase of load torque, the transmission error amplitudes of reducer are increasing, but the amplitude growth rate is decreasing. Compared with no-load conditions, the increase of theoretical transmission errors of the reducers under rated torque is as 73.1%, and the increase of experimental transmission errors under rated torque is as 58.9%.
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    Development and Applications of Metal Laser Additive Manufacturing Technology for High-end Equipment
    Kai YANG, Lei WANG, Yongkai TANG, Moubin LIU, Ziao GUO
    China Mechanical Engineering    2025, 36 (09): 2068-2080.   DOI: 10.3969/j.issn.1004-132X.2025.09.019
    Abstract495)   HTML40)    PDF(pc) (3960KB)(631)       Save

    A comprehensive review of the innovative applications and development of laser additive manufacturing technology in high-end equipment manufacturing was provided. Firstly, the basic principles and advantages were introduced, including the ability to achieve integrated manufacturing of complex structures, optimized design of materials and structures, and improvement of component performance. Further, the innovative opportunities brought by laser additive manufacturing technology to high-end equipment manufacturing in aspects were discussed such as new material development, new process innovations, new structures design, and new functions integration. The challenges faced in the applications of laser additive manufacturing technology in high-end equipment manufacturing were analyzed, such as technical difficulties in material system development and new material applications, manufacturing equipment development, online monitoring and quality control technology during the manufacturing processes, and improvement of post-processing technologies. Finally, the future development trends of laser additive manufacturing technology for high-end equipment were outlooked.

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    Tribological Properties of Polyelectrolyte-Modified PEEK Composite Materials
    GAO Chuanbao, ZHANG Xinyue, CEN Jiajia, CHEN Qin, FENG Haiyan, CHEN Kai, ZHANG Dekun
    China Mechanical Engineering    2026, 37 (1): 14-21.   DOI: 10.3969/j.issn.1004-132X.2026.01.002
    Abstract366)   HTML100)    PDF(pc) (2572KB)(631)       Save

    To enhance the tribological properties of PEEK, a “modify-then-form” approach was proposed. Hydrophilic SPMK was grafted onto the PEEK powder surface via UV-induced polymerization, then the PEEK-SPMK composites were prepared by hot-pressing. The friction and wear behaviors of modified PEEK under various operating conditions were analyzed, revealing the influence mechanism and lubrication mechanism of polyelectrolyte SPMK powder modification on the tribological behavior of PEEK composites.Results indicate that SPMK powder modification significantly enhances PEEK surface wettability. The friction coefficient(0.028) and wear rate(5.6×10-7 mm³/(N·m)) of PEEK-SPMK in physiological saline are markedly reduced compared to pure PEEK.

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    Vibration and Lubrication Characteristics of Railway Vehicle Axle Box Bearings under Wheel-rail Excitation
    MA Qiaoying, YANG Shaopu, LIU Yongqiang,
    China Mechanical Engineering    2024, 35 (04): 580-590.   DOI: 10.3969/j.issn.1004-132X.2024.04.002
    Abstract877)      PDF(pc) (12680KB)(625)       Save
    An axle box bearings coupled with a railway vehicle model was developed based on Hertz contact and elastohydrodynamic lubrication theory. The effects of wheel-rail excitations on the vibration and oil film stiffness characteristics of axle box bearings were investigated. MATLAB/Simulink and UM were used to establish the bearing dynamic model and the railway vehicle model, respectively. The coupling relationship between the two was realized through the interaction force. The typical fault forms of bearings and wheelsets were simulated, and the impacts of these faults on bearing vibration and lubrication characteristics were analyzed in detail. The results show that lubrication may effectively reduce bearing vibrations. The partial bearing faults may increase the oil film stiffness, and bearing faults and wheel flats have a significant impact on lubrication. In addition, wheel-rail excitations reduce the vibration ratio of the bearing outer ring while increasing the vibration of other vehicle components and little effects on the vibrations of the car body.
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    Design and Analysis of a Novel Weak-coupling Parallel Hip Exoskeleton with Large Angle of Rotation
    XU Jilong, LIU Fucai, NIU Yunzhan
    China Mechanical Engineering    2023, 34 (21): 2540-2547.   DOI: 10.3969/j.issn.1004-132X.2023.21.003
    Abstract764)      PDF(pc) (7047KB)(621)       Save
    A novel bio-syncretic hip exoskeleton with large-angle and weak-coupling characteristics was proposed to solve the problems such as small workspace, difficult forward kinematics modeling, and complex control of parallel hip exoskeletons. The detailed structures of two-stage prismatic joint were designed, and the expression for calculating the slope of the groove was obtained. The man-machine complexs forward and inverse position solutions were derived by closing-vector-circle method. The inverse Jacobian matrix was obtained by taking the derivative of the inverse position solution equation. Performance analysis shows that the man-machine complex has the advantages such as large range motion, no internal singularities, good force transfer performance, and easy control.
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    Influences of Rotational Speed and Flow Rate on Pressure Pulsations of a Rim-driven Axial Flow Pump
    Mengjie CHEN, Zhuo ZHANG, Wu OUYANG, Chenxing SHENG, Bao LIU, Wei LIU
    China Mechanical Engineering    2025, 36 (10): 2198-2206.   DOI: 10.3969/j.issn.1004-132X.2025.10.005
    Abstract416)   HTML56)    PDF(pc) (5874KB)(621)       Save

    A novel RDP generated pressure pulsations during operations, which might negatively impact pump performance and system stability. The numerical simulation was employed to analyze the external characteristics and internal flow patterns of RDP under different rotational speeds and flow conditions. Utilizing POD, the main energy modes were extracted through spatiotemporal feature decomposition to investigate the influences of rotational speed and flow rate on the pressure pulsation at the trailing edges of the impeller blades, revealing the relationship between nonlinear dynamics and fluid-structure interaction phenomena. The results show that each rotational speed corresponds to a distinct optimal operating point, with the optimal point shifting towards lower flow rates as the rotational speed decreases. Moreover, the pressure pulsations are predominantly governed by nonlinear dynamics behavior, with nonlinear interaction effects between the impeller blades and guide vanes becoming more pronounced at lower rotational speeds and higher flow rates.

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    Design of Jig and Fixture for Machining Precision Forged Blade Tenons of Aeroengine
    ZHANG Shen1, LIANG Jiawei2, WU Dongbo3, WANG Hui4, ZHAO Bing1, XU Lijun5, ZHOU Fen5
    China Mechanical Engineering    2025, 36 (04): 703-714.   DOI: 10.3969/j.issn.1004-132X.2025.04.007
    Abstract1970)      PDF(pc) (9510KB)(618)       Save
    Precision forged blades of aeroengine were a typical thin-walled parts with complex curved surface. When milling the blade tenons, it was difficult to locate and easy to produce deformations and vibrations. Aiming at the above problems, a design method of multi-point clamping fixture for precision forged blades was proposed, and a low stress hard clamping fixture was designed. Static analysis was used to optimize the clamping position, select the coping element materials and optimize the clamping method. The effectiveness of the fixture was tested by modal tests and vibration tests. The results show that the low-band amplitude of the system is reduced by 50%, the high-band amplitude by 75%, the first-order resonance frequency is increased from 210 Hz to 402 Hz, the damping ratio under the peak value is increased from 17.4% to 25.9%, the effective value of vibration displacement signals is reduced by 35%, and the machining error margin is reduced by 59%.
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    Numerical Simulation of Residual Stress and Welding Deformation for High Strength Steel Q960E Butt-welded Joints
    LUO Wenze, CHENG Huimei, LIU Hongyan, WANG Yifeng, YE Yanhong, DENG Dean
    China Mechanical Engineering    2023, 34 (17): 2095-2105,2141.   DOI: 10.3969/j.issn.1004-132X.2023.17.009
    Abstract1189)      PDF(pc) (10205KB)(616)       Save
     A multi-pass butt-welded joint of low alloy high strength steel Q960E was prepared by equal strength matching wire and mixed gas shielded welding method. Microstructure, hardness distribution, welding temperature cycles, welding deformation and welding residual stress were observed and measured by experiments. With the consideration of the microstructure characteristics of Q960E, a thermal-elastic-plastic finite element method which considered the coupling behaviors among multiple physical fields of “thermal-microstructure-stress” was developed based on SYSWELD software platform. The material model focused on solid-state phase transformation in the heat-affected zones(HAZs). The JMAK equation was employed to describe the austenitization processes during the heating stages, while the K-M equation was utilized to simulate the martensitic transformation processes in the cooling stages. At the same time, the transformation-induced plasticity in the cooling processes was considered based on the Leblond model. The comparison between the numerical simulation results and the experimental measurements shows that both the residual stress distribution and the welding deformation obtained by the finite element model are in a good agreement with the measured data, and the numerical simulation results also show that the solid-state phase transformation has a significant effect on the distribution and magnitude of welding residual stress in the HAZ of Q960E steel butt-welded joints. 
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    Research Progresses for Machining Characteristics and Field-assisted Techniques of γ-TiAl Alloys
    FAN Tao1, 2, YAO Changfeng1, 2, TAN Liang1, 2, SHAN Chenwei1, 2, XIA Ziwen1, 2
    China Mechanical Engineering    2025, 36 (04): 636-645.   DOI: 10.3969/j.issn.1004-132X.2025.04.001
    Abstract2257)      PDF(pc) (25364KB)(614)       Save
    γ-TiAl alloys, due to their low density, high specific strength and excellent high-temperature oxidation resistance had broad application potentials in the aerospace fields. However, due to their high brittleness and low room-temperature plasticity, they were considered typical difficult-to-machine materials, with challenges such as high cutting forces, rapid tool wear and surface defects during the machining processes. In recent years, field-assisted machining technologies provided new solutions to these issues. The material properties, machining characteristics, and surface integrity of γ-TiAl alloys were systematically analyzed, with a focus on the research progresses of field-assisted machining technologies, including their applications in reducing cutting forces, extending tool life and improving surface quality. Additionally, the current research limitations and future development trends were sorted out, aiming to provide theoretical and technical references for the efficient machining of γ-TiAl alloys. 
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