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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 Abstract （2199）      PDF（pc） （5000KB）（1701）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1106）      PDF（pc） （7794KB）（1490）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （2158）      PDF（pc） （3068KB）（1433）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1177）      PDF（pc） （9652KB）（1274）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （802）   HTML （161）    PDF（pc） （3972KB）（1219）       Knowledge map    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. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1626）      PDF（pc） （4422KB）（1155）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （2686）      PDF（pc） （8675KB）（1151）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1031）      PDF（pc） （9923KB）（1069）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1679）      PDF（pc） （7393KB）（1040）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1281）      PDF（pc） （6363KB）（1008）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1160）      PDF（pc） （8185KB）（1007）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （811）   HTML （127）    PDF（pc） （7456KB）（1004）       Knowledge map    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. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1616）      PDF（pc） （50387KB）（996）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （434）   HTML （135）    PDF（pc） （2572KB）（937）       Knowledge map    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{}^{-\mathrm{7}} mm³/（N·m）） of PEEK-SPMK in physiological saline are markedly reduced compared to pure PEEK. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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Method for Accelerated Tribological Property Evolution Experiments of Conformal Contact Surfaces in Mixed Lubrication Regime ZHANG Ziyang, GONG Yajing, WANG Yuechang China Mechanical Engineering    2026, 37 (1): 22-29.   DOI: 10.3969/j.issn.1004-132X.2026.01.003 Abstract （313）   HTML （106）    PDF（pc） （2108KB）（925）       Knowledge map    Save An acceleration experimental design method for hybrid-lubrication conformal-contact surface tribological evolution was proposed. The method was based on the concept of “viscosity-reduction acceleration”， where the asperity contact states were preserved while the evolution of tribological behavior was accelerated by increasing the interaction frequency between surface asperities. The approach was validated by Plint TE-92 friction and wear tester.The results show that at the non-accelerated condition （sliding speed is as 0.2 m/s， temperature is as 25 °C， duration is as 20 min） and the corresponding accelerated condition （sliding speed is as 0.4 m/s， temperature is as 47 °C， duration is as 10 min） share the highly consistent values of friction coefficient， and 3D surface parameters Sq and Ssk. It indicates that the wear effect of 10-minute in test with accelerated parameters is equivalent to that of 20-minute in test with non-accelerated parameters. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （914）      PDF（pc） （8141KB）（913）       Knowledge map    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． Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （991）      PDF（pc） （9034KB）（906）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1855）      PDF（pc） （11269KB）（899）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （834）      PDF（pc） （1996KB）（892）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （498）   HTML （89）    PDF（pc） （5874KB）（867）       Knowledge map    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. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （2135）      PDF（pc） （7015KB）（854）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （988）      PDF（pc） （17686KB）（853）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1008）      PDF（pc） （8767KB）（853）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （2388）      PDF（pc） （25364KB）（850）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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Aerodynamic Optimization of Radial Turbines Based on Surrogate Model of Pre-screened Strategies and DFFD Parameterization Tianqi WANG, Jiang CHEN, Hang XIANG, Xiaofei SONG China Mechanical Engineering    2025, 36 (10): 2171-2178.   DOI: 10.3969/j.issn.1004-132X.2025.10.002 Abstract （606）   HTML （101）    PDF（pc） （3107KB）（842）       Knowledge map    Save There were some problems such as difficult geometric control， many control variables and low optimization efficiency in aerodynamic optimization of three-dimensional complex blade surfaces of radial turbines. To solve these problems， multi-degree-of-freedom parameterization of radial turbine runner and blade multidimensional geometry were implemented based on DFFD method. Then an differential evolution algorithm assisted by surrogate models of pre-screened strategies（Pre-SADE） was introduced. Finally， a data-driven three-dimensional aerodynamic optimization platform for centripetal turbines was constructed by combining python and batch script of process automation. The platform was used to carry out the joint optimization design of flow channel-static/rotating blades for the radial turbines. The results show that after optimization， the adiabatic efficiency and mass-flow of the design point of the centripetal turbines are increased by 1.66% and 1.7% respectively， which effectively reduces the shock intensity in the guide vane channel and the shock loss on the suction surfaces of the guide vane， and the efficiency characteristics of the design rotational speed are improved in all working conditions. Finally， the method and platform may ensure the aerodynamic optimization efficiency， and effectively reduce the optimization variables and sample real evaluation times， significantly improve the optimization efficiency， and meet the rapid and elaborate optimization design requirements of radial turbines. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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A Sequential Simulation Method for Dynamic Uncertainty Analysis of Rigid-flexible Coupling Systems under Interval Process Excitations LIU Yanhao, NI Bingyu, TIAN Wanyi, JIANG Chao China Mechanical Engineering    2024, 35 (05): 770-783.   DOI: 10.3969/j.issn.1004-132X.2024.05.002 Abstract （1736）      PDF（pc） （9281KB）（838）       Knowledge map    Save For the dynamic problem of rigid-flexible coupling systems under dynamic uncertain excitations, an interval process model-based sequential simulation method was proposed for uncertainty analysis, which aimed to obtain the upper and lower bounds of the system dynamic responses such as structural vibrations and mechanism kinematics, by sequential sampling of the interval process and the rigid-flexible coupling dynamics simulations. The construction and numerical solution of the dynamic equation of the rigid-flexible coupling systems with central rigid body and flexible beam were introduced. Aiming at the dynamic analysis of rigid-flexible coupling systems under uncertain dynamic excitations, the interval process model and the interval K-L expansion were introduced to quantify and represent the dynamic uncertainty efficiently, and a sequential simulation method was proposed to solve the upper and lower bounds of the dynamic responses of the system mechanism motions and structural vibrations. The method used a sequential simulation strategy to identify the interval process parameter sample sets that contributed to the upper or lower bounds of dynamic responses in the cur rent simulation sequence, and served as the local encrypted sampling center in the next simulation sequence, which might effectively avoid the inefficient convergence problem caused by excessive invalid sampling simulations when calculating the upper and lower bounds of dynamic response in direct Monte Carlo simulation. Finally, three examples were given to verify the effectiveness of the proposed method. The results show that the sequential simulation method has better computational efficiency and accuracy than that of the direct Monte Carlo simulation method for solving the upper and lower bounds of the rigid-flexible coupling systems large overall motions and vibration responses. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （934）      PDF（pc） （12680KB）（827）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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Bearing Fault Diagnosis of Mining Drilling Rig with Time-frequency-fused Deep Network ZOU Xiaoyu1, 3, SUN Guoqing1, WANG Zhongbin1, 3, PAN Jie2, LIU Xinhua1, 3, LI Xin1, 3 China Mechanical Engineering    2024, 35 (08): 1405-1413，1448.   DOI: 10.3969/j.issn.1004-132X.2024.08.009 Abstract （2192）      PDF（pc） （9001KB）（811）       Knowledge map    Save To solve the problems of weak and noisy bearing fault features caused by the low-speed and heavy-load operating characteristics of mining drilling rigs, a fault diagnosis method was proposed for mining rig bearings, named time-frequency-fused deep network. It considered the limitations of fault diagnosis with single modality, and then jointly characterizes two modal features of the time domain and time-frequency domain. The designed diagnostic network differentially embeded specific attention mechanism in different modules to extract multi-dimensional key fault features. Finally, the proposed method was validated on the experimental equipment and the Case Western Reserve University bearing dataset. The results show that the proposed method may automatically extract sufficient fault features combining two domains. It has higher accuracy and noise immunity than those with a single domain. Reference | Related Articles | Metrics | Comments（0）

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Fault Diagnosis of Rotating Machinery Bearings Based on Multi-source Wavelet Transform Neural Network GUO Haiyu1, ZOU Shenggong1, ZHANG Xiaoguang2, 3, 4, LU Fanfan2CHEN Yang2, WANG Han2, XU Xinzhi2 China Mechanical Engineering    2024, 35 (11): 2026-2034.   DOI: 10.3969/j.issn.1004-132X.2024.11.014 Abstract （2197）      PDF（pc） （5837KB）（809）       Knowledge map    Save  A multi-source wavelet time-frequency transform convolutional neural network was proposed to address the issues of limited fault samples in rotating machinery bearing fault diagnosis, along with the vulnerability to overfitting and the poor generalization ability of traditional models when dealing with small datasets. Initially, for high-frequency data obtained from a single vibration sensor, a wavelet transform-based time-frequency convolutional layer was formulated to integrate both the real and imaginary components of wavelet coefficients. Here, the real component represented the amplitude information of vibration signals, while the imaginary component depicted phase information. Compared with a convolution layer that only considering real part, this convolutional layer may extract comprehensive time-frequency features. Subsequently, the time-frequency convolutional layer was employed to independently extract features from high-frequency data acquired by multi-sensors on a single device, and these features were then concatenated. Lastly, a dense module utilizing lightweight depth-separable convolution was developed to conduct further feature extraction from the concatenated features, facilitating fault classification. The effectiveness of the model was confirmed through experimentation using Case Western Reserve University rolling bearing dataset, achieving an accuracy of 98.5%.Additionally, the model was deployed for fault diagnosis in rotary kilns, belt conveyors, and grate coolers, demonstrating an average accuracy of 97.19%. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1471）      PDF（pc） （3896KB）（807）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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Design of Twisting Climbing Wheeled Inspection Robot for Mining Wire Ropes TANG Chaoquan, TONG Binghang, TANG Wei, ZHANG Gang, WANG Siyuan, TANG Hongwei, LIU Bei, ZHOU Gongbo China Mechanical Engineering    2024, 35 (10): 1732-1739.   DOI: 10.3969/j.issn.1004-132X.2024.10.003 Abstract （934）      PDF（pc） （6279KB）（806）       Knowledge map    Save In response to the unmanned inspection requirements of mining wire ropes, a rope-twisting climbing inspection robot was designed and developed. Compared to traditional axial climbing robots, which required approximately 91.5% of the driving force. When carrying a load of 3 kg, the robot may overcome obstacles with a height 0.6 mm higher than that of axial climbing robots. With an obstacle height of 3 mm, the maximum load capacity exceeds that of axial climbing robots by 0.4 kg. Climbing experiments were conducted under simulated deep mine conditions with wire rope vibrations. The results show that the climbing robots exhibite stable climbing performance when the wire ropes are stationary, achieving a maximum climbing speed of 8.25 m/min and capable of continuous climbing for 500 m. Under low-frequency large-amplitude vibration conditions, the climbing speed of the robot is higher than that when stationary, while under high-frequency small-amplitude vibration conditions, slight fluctuations in climbing speed are observed due to wire rope vibrations. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1510）      PDF（pc） （9273KB）（779）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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Study on Lubricating Performances and Mechanism of Nano-carbon Balls Cutting Fluids SUN Hao1, LAN Qixin2, YAO Bin2, LU Jingjing1, ZHANG Jinhui2, PAN Zhirong2, ZHAO Kexin2 China Mechanical Engineering    2025, 36 (04): 715-723.   DOI: 10.3969/j.issn.1004-132X.2025.04.008 Abstract （2101）      PDF（pc） （8056KB）（776）       Knowledge map    Save Nano-carbon balls cutting fluid was applied to the cutting processes of difficult-to-machine aerospace gear steels(15Cr14Co12Mo5Ni2W), and the lubrication enhancement effects of nano-carbon particles on the cutting fluid were investigated. Firstly, a cutting force model for metal cutting was established to analyze the relationship between cutting lubrication and cutting forces. Furthermore, through combined friction-wear tests and milling experiments, the lubrication performance of nano-carbon balls cutting fluid was evaluated in terms of friction coefficient, wear volume, friction surface quality, and cutting forces. Compared with the base cutting fluid, when the mass fraction of nano-carbon is reached 0.02%, the milling forces for the gear steels are decreased by over 10%, and surface roughness is reduced by more than 15%. Experimental observations reveal that nano-carbon particles on the friction contact surfaces preferentially are adsorbed onto micro-peak regions with higher surface free energy, forming a nano-carbon adsorption film. Lubrication mechanism analysis indicates that this adsorption film may exert a friction-reducing “micro-bearing” effects. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （2111）      PDF（pc） （9510KB）（759）       Knowledge map    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%. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （996）      PDF（pc） （9016KB）（745）       Knowledge map    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. Reference | Related Articles | Metrics | Comments（0）

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Research on Two-level Fusion Strategy of Unmanned Driving Perception Information Target-decision under Tunnel Environments WANG Maosen, BAO Jiusheng, XIE Houkang, LIU Tonggang, YIN Yan, ZHANG Quanli China Mechanical Engineering    2024, 35 (03): 427-437.   DOI: 10.3969/j.issn.1004-132X.2024.03.005 Abstract （928）      PDF（pc） （4400KB）（744）       Knowledge map    Save Based on the special driving environment in the tunnel and the perception requirements of unmanned driving, appropriate sensors and hardware were chosen to build a test vehicle and a perception system of multi-sensor fusion of millimeter-wave radar and camera. A two-level information fusion algorithm of “target-decision” was proposed based on YOLOv4 target-level information fusion algorithm and improved D-S evidence theory. Finally, a verification test of perception information two-level fusion was carried out in the urban road tunnel environments. The results show that in the tunnel environments, compared with the single camera or the millimeter-wave radar sensing results, the target-level fusion result based on the association of the camera and the millimeter-wave radar sensor to perceive the ROI area may improve the recognition accuracy by 9.51%, making up for the shortcomings of a single sensor in the tunnel environment perception technology. Based on the target-level fusion perception results, using the improved D-S evidence theory algorithm to perform decision-level fusion, compared with the single target-level fusion results, the false detection rate is reduced by 3.61%, which significantly improves detection accuracy. By adopting the multi-sensor sensing information target-decision-making two-level fusion strategy, it may meet the reliable sensing requirements of unmanned vehicles in the special tunnel environments, and provide theoretical and technical support for promoting the applications of unmanned controlled technology. Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （670）   HTML （68）    PDF（pc） （3960KB）（739）       Knowledge map    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. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

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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 Abstract （1034）      PDF（pc） （5263KB）（733）       Knowledge map    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.  Reference | Related Articles | Metrics | Comments（0）

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Bearing Fault Data Generation Method Based on WLT-ACGAN JIAO Huachao, SUN Wenlei, WANG Hongwei China Mechanical Engineering    2025, 36 (03): 546-557.   DOI: 10.3969/j.issn.1004-132X.2025.03.018 Abstract （2243）      PDF（pc） （7836KB）（729）       Knowledge map    Save Using data generation method to generate high-quality data which made time-domain and frequency-domain features consistent with the real signals of bearing faults, and constructing balanced dataset, were of great significance for the establishment of an efficient diagnostic model of bearing faults in the case of data imbalance. In order to address the limitations of the existing data generation methods, which focused on a single feature in time or frequency domains, WLT-ACGAN was proposed herein. Firstly, a WLT network was constructed with a multi-layer neural network based on the principle of wavelet transform. The wavelet transform and inverse transform were simulated, and the mapping relationship between time-domain signal and frequency-domain signal was established. Secondly, the WLT network was embedded into ACGAN model as the primary component of model generator. Finally, two discriminators were constructed with different functions, enabling the improved ACGAN to learn time-domain and frequency-domain feature information of authentic bearing vibration signals concurrently. Experimental results show that the bearing vibration signals generated by WLT-ACGAN model exhibit consistent time-domain and frequency-domain features with those of the actual bearing vibration signals. Furthermore, the fault diagnostic model constructed with the balanced dataset augmented by the generated signals exhibits a high degree of accuracy when the data are imbalanced. Reference | Related Articles | Metrics | Comments（0）

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Tribological Properties and Mechanism of Nanostructured Carbon Films under Coupling Effect of Temperature and Electric Field YU Zhimin, CHEN Lei, FAN Xue China Mechanical Engineering    2026, 37 (1): 30-39.   DOI: 10.3969/j.issn.1004-132X.2026.01.004 Abstract （328）   HTML （55）    PDF（pc） （7563KB）（726）       Knowledge map    Save The nanostructured carbon films including amorphous carbon films and graphene nanocrystalline carbon films were prepared on SiO2 substrates. A self-designed reciprocating tribometer capable for applying coupled multi-physical fields was employed to investigate the tribological properties of the different nanostructured carbon films under the coupling effect of temperature and electric field. At room temperature， the electric field was the dominant factor for affecting the friction coefficient of nanostructured carbon films. When the temperature of tribopair was 200 ℃， temperature became the main influencing factor. Under the coupling effects of temperature and electric field， the structured evolution to graphitic-like structure leads the reduction of friction coefficient of amorphous carbon film. While the nanostructure of graphene nanocrystalline carbon film is stable， but the aggravated wear results in significant fluctuations of friction coefficient. Table and Figures | Reference | Related Articles | Metrics | Comments（0）