20 November 2025, Volume 61 Issue 22
    

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  • Features and Identification Indicator Construction of Aero-engine Rubbing Faults
    ZHOU Tao, ZHANG Weiyu, WANG Hao, LIU Bin, HU Minghui, JIANG Zhinong
    Journal of Mechanical Engineering. 2025, 61(22): 1-16. https://doi.org/10.3901/JME.2025.22.001
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    Blade-casing rubbing is one of the typical faults in aero-engines, but due to the complex structure of the equipment, diagnosing rubbing faults is still a challenge. Taking into account the effects of casing vibration and blade vibration, setting up non-uniform gaps and improves the application method of rubbing force. A model is constructed to study the vibration characteristics of rubbing faults, and the conclusions are verified through an aero-engine fault simulation test rig. The model simulation and experimental results show that rubbing faults will cause a decrease in the amplitude of the rotor vibration rotational frequency and an increase in the amplitude of the casing vibration rotational frequency; In the vibration spectrum of the rotor and casing, the various harmonics of the rotational frequency will be excited to varying degrees in the rubbing fault; Rubbing faults can also significantly excite the blade passage frequency in the vibration of the casing. Based on the conclusions obtained from model simulation and experiments, a fault identification indicator based on the vibration response of the casing is constructed. The numerical results demonstrate that the indicator have anti-interference ability for unbalance faults and can accurately reflect the changes in the degree of rubbing. Finally, the effectiveness of the constructed indicator was verified through the aero-engine test rig data and test flight data. The research results can provide reference for the diagnosis of blade-casing rubbing faults in the aero-engine.
  • Research on Multiphysics Fusion Sensor Technology Based on Magnetic Flux Leakage-electromagnetic Acoustic Transducer
    TANG Qin, GAO Bin, XUE Songwen, FAN Yongzhao, WEI Yunjin, SHEN Liang
    Journal of Mechanical Engineering. 2025, 61(22): 17-27. https://doi.org/10.3901/JME.2025.22.017
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    To overcome the limitations of a single non-destructive testing method, a sensing structure that integrates magnetic flux leakage（MFL） detection and electromagnetic acoustic transducer（EMAT） detection methods is proposed to simultaneously detect surface and internal defects in steel specimens. The proposed hybrid sensor structure makes full use of the magnetic circuit characteristics of the MFL and EMAT. The combination of the yoke and permanent magnets creates a horizontal magnetic field inside the sample to detect defects on and near the surface of the sample. Secondly, the local vertical magnetic field provided by the magnetization structure of the MFL interacts with the EMAT excitation coil to produce ultrasonic waves in the specimen to identify internal flaws in the specimen. The excitation source for MFL is quasi-static and the ultrasonic signal is a pulsed excitation source at 2 MHz. The significant frequency difference between the two signals is helpful in reducing mutual interference. Simulations and experiments show that the proposed sensing structure can overcome the blind zone caused by near-field emission in EMAT and the depth limitation of MFL, and is able to simultaneously detect and classify both surface defects and internal blind hole defects in large thickness ferromagnetic sample.
  • Preventive Maintenance Strategies that Consider Reversible Deterioration Grading
    WANG Zhiming, ZHANG Xinyong
    Journal of Mechanical Engineering. 2025, 61(22): 28-35. https://doi.org/10.3901/JME.2025.22.028
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    In order to prolong the service life of the system, based on the characteristic that the system deterioration can be reversed to varying degrees, it is proposed to decompose the deterioration into reversible deterioration and irreversible deterioration, and take the amount of reversible deterioration that can be eliminated by preventive maintenance（PM） as the basis for classification of PM grades. Combining the increasing factor of system failure rate and decreasing factor of service age, taking the total running time before replacement as the optimization objective, the lowest PM interval time and reliability threshold as the constraint conditions, the grade of each preventive maintenance is determined by economic analysis, and a multi-level preventive maintenance model based on reversible deterioration grading is established. Finally, taking the electrical control system of a CNC machine tool as an example, the effectiveness of the proposed strategy is verified by numerical analysis. The results show that, compared with PM without considering reversible deterioration, the multi-level PM strategy considering reversible deterioration can extend the total running time of machine tool electrical system to 19.21%, and for high-output equipment that pays attention to output value, the significant increase of running time is far more important than the small reduction of cost; At the same time, the change of irreversible deterioration has obvious influence on the reliability of machine tools:the lower the proportion of irreversible deterioration, the later the system reliability threshold arrives, and the maintenance interval increases.
  • Magnetic Vector Compensation Control for Desired Target Orientation of Permanent Magnet Spherical Motor
    ZHANG Yongshun, WANG Li, WU Zhenhua, LIU Gaoren
    Journal of Mechanical Engineering. 2025, 61(22): 36-46. https://doi.org/10.3901/JME.2025.22.036
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    For solving the problems of complex electromagnetic structure, redundant control variables and magnetic torque singularity of permanent magnet spherical motor, according to the rotational coaxial effect of the permanent magnet rotor, in which whose axis always tends to rotate toward the rotational axis of the rotating magnetic field, using the three-axis orthogonal combination coil as the stator, a two-degree-of-freedom permanent magnet spherical motor mainly composed of universal follow-up mechanism with built-in permanent magnet rotor is developed. Aiming at the phenomenon in which the payload generates the orientation deviation between the rotating axis of the magnetic field and the axis of the permanent magnet rotor coaxial with the output end of the motor, an accurate drive and control method for approaching the trace of the desired target orientation of the output end of the motor with payload is proposed by magnetic vector orientation compensation. Specifically, the three-phase current formula with the pitch and yaw angle of the rotating axis of the magnetic field as the independent control variables is used to superimpose the rotating magnetic field, the rotational coaxial magnetic moment model and the slip angle model related to the compensation orientation parameter of the field rotation axis and the target orientation parameter of the motor are derived, achieving the decoupling of the yaw and pitch magnetic moment components. In view of the fact that permanent magnet rotor at the balance point has gyro stability, by ignoring the inertial force of the system, the static torque balance equation of the motor is established at each balance control point of the desired target orientation, and compensation orientation trajectory of the magnetic vector is obtained, as a result, the analytic solution of the drive currents correspondence to magnetic moments each to each is achieved, which lays a foundation for accurate drive and control of permanent magnet spherical motor.
  • Research on Posture-controlled Method of Gas Tungsten Arc and Wire-based Deposition for Repairing Complex Blades
    CHEN Zhixu, CHEN Yuanhang, LI Chenxing, YANG Chunli
    Journal of Mechanical Engineering. 2025, 61(22): 47-56. https://doi.org/10.3901/JME.2025.22.047
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    Repairing high-pressure compressor blades of aircraft engines using the gas tungsten arc（GTA） and wire-based deposition is a technical challenge, the fixed posture deposition of the welding torch is easy to cause the deviation between the repair region and the digital model. Aiming at the repair technical requirements of blisk blade, a path-planning method and a posture control-planning method of welding torch are proposed for GTA and wire-based deposition, which mainly regulating the yaw angle during the deposition to make the welding torch follow the blade’s curved surface inclination to improve the formation. The results show that the welding-torch inclination（WTI） changes the arc-pressure distribution and promotes the liquid metal filling into the inner edge, which increases the deposition width; With the increase of inclination angle, the liquid metal is more easily spread outward, simultaneously, which reduces the risk of collapse. The sidewall waviness of WTI is reduced by about 0.4 mm compared with that of the vertical posture, the effective thickness increases by about 0.44 mm, and the surface roughness is reduced by about 12.7%. The repaired blade has on obvious deposition defect, which avoids the forming deviation of vertical-posture deposition. The minimum unilateral machining allowance is about 0.88 mm, provides a guarantee for finish machining. Controlling the posture of the welding torch during the deposition process will provide a method reference for improving the formability of complex curved structures.
  • Effect of Pre-deformation and Heat Treatment Process on Stress Distribution in Spinning of 2219 Aluminum Alloy Thin-walled Components
    LU Shulin, WANG Jianfeng, ZHAN Xiaohong, DUAN Yuhang, CHENG Lihong, HUANG Shuwen, ZHAO Yaobang
    Journal of Mechanical Engineering. 2025, 61(22): 57-68. https://doi.org/10.3901/JME.2025.22.057
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    In order to prolong the service life of repeatable rocket, the effects of pre-deformation and heat treatment processes on the residual stress of 2219 aluminum alloy spinning thin-walled structure in the manufacturing process of rocket tank bottom were studied.. Based on Abaqus software, a spinning simulation model considering pre-deformation and heat treatment is established. The simulation results of stress and deformation are transmitted by pre-defined field, and the blind hole method is used for experimental verification. Comparing the spinning simulation results with or without pre-deformation process, it is found that the strain in the middle region of the “pre-deformation + spinning” part is more uniform, the wall thickness changes less, and the thinning rate is reduced by 5.2%. This is due to the pre-forming effect, the deformation of the subsequent spinning process is reduced, and the deformation of the spinning process is more stable. Without pre-deformation process, a stress ring composed of stress concentration areas is observed at the outer edge of the “single spinning” parts, and the maximum residual stress value is 173.9 MPa. By contrast, the stress ring of the “pre-deformation + spinning” parts is affected by the pre-deformation process induced stress. The maximum residual stress is increases by 41.3%, up to 245.7 MPa, but the stress ring distribution is more uniform and the width decreases, and the stress concentration area is refined. Subsequently, heat treatment was applied to the “pre-deformation + spinning” parts. The results show that heat treatment has no significant effect on strain and thinning rate, but the residual stress after spinning can be significantly reduced by 63.5%, which is helpful to alleviate the stress concentration caused by spinning and homogenize the residual stress distribution.
  • Surface Crack Propagation Life Study of Welded Structures Using Phased-array Ultrasonic Total Focusing Imaging
    WANG Chao, YANG Bing, ZHU Tao, YANG Guangwu, XIAO Shoune
    Journal of Mechanical Engineering. 2025, 61(22): 69-79. https://doi.org/10.3901/JME.2025.22.069
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    Facing the needs of integrity assessment of welded structures in service, the state of fatigue crack evolution on the surface of welded joints is of paramount importance for the assessment of their fatigue life. Currently, the method for effective monitoring of fatigue crack propagation on the surface of welded structures has not been established, and it is difficult to characterize the effect of crack morphology evolution on the fatigue life of welded structures. An innovative method for monitoring the three-dimensional fatigue crack propagation state on the surface of welded structures based on ultrasonic total focus phased array imaging is proposed. First, the imaging technique is used to perform fatigue tests on 8 mm thick aluminium alloy full-size butt joints, and the morphological evolution of surface fatigue cracks in the weld toe area is obtained by real-time imaging. Then, the imaging results of crack propagation were compared and analysed with the fracture morphology characteristics to verify the effectiveness of the proposed condition monitoring method. Finally, the stress intensity factor at the crack leading edge was optimized by fitting the monitoring data of crack depth a and length c into the segmented function introduced into the BS7910 analytical function with a/c and a/t as parameters. The results show that the condition monitoring method based on ultrasonic total focus phased array imaging can effectively capture the dynamic evolution of the fatigue crack depth a and length c at the weld toe. The evolution law of surface crack morphology under through-thickness failure mode is completely revealed. In addition, the dynamic crack morphology feature analysis function is introduced to significantly improve the accuracy of fatigue crack propagation life assessment of welded structures. The method provides a new way of reflection for the condition monitoring of fatigue crack propagation and life prediction of welded structures, which has important theoretical significance and engineering application value.
  • Research on the Fabrication and Hot-pressing Forming Mechanism of Polymer Array Micro-groove Wick Structure
    TANG Heng, HUANG Qiang, WU Chunxia, SUN Yalong, TANG Yong
    Journal of Mechanical Engineering. 2025, 61(22): 80-87. https://doi.org/10.3901/JME.2025.22.080
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    Addressing the issues of simplistic design and poor heat transfer in flexible polymer vapor chamber groove-wick structures,the secondary hot-pressing is employed to fabricate an array of micro-groove wick structures on polymer surfaces. Initially,a metal mold with micro-grooves is crafted using electrical discharge machining（EDM）. This mold’s surface structure is then transferred onto an amorphous alloy through hot-pressing, resulting in the creation of an amorphous alloy mold. Subsequently,the surface structure of the amorphous alloy mold is replicated onto the polymer surface via another hot-pressing step. The impacts of various hot-pressing parameters,including temperature,pressure,and time,on the filling performance and shape accuracy of both the amorphous alloy and polymer surface structures are investigated. The findings reveal that temperature plays a significant role during the hot-pressing of the amorphous alloy mold,achieving a maximum filling rate of 99.76%. In contrast,pressure exerts the greatest influence during the hot-pressing of the polymer surface,yielding a maximum filling rate of 97.71%. Ultimately,the two-step hot-pressing process attains an overall filling rate of 97.48%,enabling the precise replication of the metal surface’s array of micro-groove structures onto the polymer surface. This methodology offers a novel approach for fabricating wick structures in polymer vapor chambers and provides valuable insights and references for research and applications in related fields.
  • Effect of Preheating Temperature on the Bonding Quality between Wire Arc Additive Manufactured Magnesium Alloy and Substrate
    LI Jie, FAN Jikang, CAI Baihao, DUAN Linye, YANG Dongqing, WANG Kehong
    Journal of Mechanical Engineering. 2025, 61(22): 88-96. https://doi.org/10.3901/JME.2025.22.088
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    To explore the effect of preheating temperature on the bonding quality between arc additive magnesium alloy and substrate, AZ91 magnesium alloy samples are prepared using arc additive technology under the conditions of maintaining the substrate at room and preheating temperature（25 ℃） and preheating（100 ℃, 200 ℃, 300 ℃, 400 ℃）. The macroscopic forming of the samples and the microstructure and mechanical properties of the substrate bonding position and the bottom region are analyzed in depth. The study found that the surface of the obtained sample components is smooth, but with the increase of preheating temperature, slight collapse occurred at both ends of the components, and the microstructure showed equiaxed crystal characteristics, mainly composed of α-Mg, β-Mg17Al12, and η-Al8 Mn5. At room temperature（25 ℃）, the fusion between the deposited layer and the substrate is poor, with cracks and porosity defects, and the shear strength of both is only 53.4 MPa; After preheating, the bonding between the deposited layer and the substrate is significantly improved, and the shear strength increased to 144.7 MPa at 400 ℃. The average hardness decreases from 76.9 HV to 60.9 HV as the preheating temperature increases. Meanwhile, the mechanical properties of the magnesium alloy bottom area samples obtained by arc additive manufacturing are superior to those of traditional die cast magnesium alloys. With the increase of preheating temperature, the tensile strength first increases and then decreases, and the elongation at break linearly increases.
  • Research on the Morphology, Heat Transfer, and Metal Flow Behavior of MIG-based Wire Arc Additively Manufactured Single-pass Aluminum Alloy via Integrated Model
    ZHAO Wenyong, WEI Yanhong, XU Guoxiang, HU Qingxian, WANG Yaowei
    Journal of Mechanical Engineering. 2025, 61(22): 97-108. https://doi.org/10.3901/JME.2025.22.097
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    An in-depth understanding of the inherent influence mechanism between process parameters, complex physical phenomena and forming quality is an important prerequisite for obtaining high-quality arc additively manufactured parts with reasonable structure, reliable performance and no defects. In this paper, a 3D arc plasma-droplet-molten pool integrated transient model of wire arc additive manufacturing of aluminum alloy is developed, which simultaneously considers the heating of arc plasma, droplet transfer, the vaporization of metal, the deformation of molten pool free surface, the convection of molten pool metal, the melting and solidification of metal, and the relative movement between wire and substrate. In this model, the volume of fluid（VOF） method is used to track the gas-liquid free interface, the complex thermal effect of the sheath is considered based on the “local thermodynamic equilibrium（LTE）-diffusion approximation” model, and the moving reference frame is utilized to handle the relative motion between the wire and the substrate. The accuracy of the integrated model was verified by the experimentally measured droplet transfer and deposited layer profile. Based on the established model, the influence mechanisms of welding current and travel speed on the deposited layer morphology evolution and the metal heat transfer and fluid flow behavior were analyzed. The results show that with the increase of welding current, the cross-section of deposited layer changes from arc-shaped to flattened, the temperature gradient and the flow rate of the molten pool metal increase, but the change in flow pattern is relatively small. With the increase of travel speed, the cross-section of deposited layer changes from flattened to arc-shaped, the depth and the metal temperature gradient of the molten pool decrease, and the flow behavior transition of the molten metal as a whole towards the rear of the molten pool accelerates.
  • Review on Research Progress and Application of Low-temperature Heating Techniques for Lithium-ion Batteries
    XIONG Rui, ZHU Yuhua, ZHANG Qianhui, ZHANG Kui, MEI Bingang, SUN Fengchun
    Journal of Mechanical Engineering. 2025, 61(22): 109-132. https://doi.org/10.3901/JME.2025.22.109
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    The new energy vehicles, exemplified by electric vehicles（EVs）, have embraced unprecedented opportunities for development. Lithium-ion batteries（LIBs）, leveraging their advantages such as high energy density, low self-discharge rate, and long lifespan, have emerged as the mainstream choice for EV power systems. However, the significant degradation of LIBs performance at low temperatures directly leads to reduced driving range, prolonged charging time, and potential safety hazards for EVs, posing a core challenge to their widespread adoption. Low-temperature heating, as one of the key methods to overcome the performance bottleneck of batteries at low temperatures, is currently the focus of industry research. This study comprehensively summarizes and discusses the latest advancements in low-temperature heating technologies for LIBs and their current application status in real vehicles, encompassing external heating, internal heating, and hybrid heating. It thoroughly elaborates on the principles, latest progress, strengths, weaknesses, and potential optimization opportunities of each technology. Additionally, it conducts a qualitative comparison of each technology and analyzes the current application status of heating technologies in real vehicles. Finally, the paper explores the future development prospects of low-temperature heating technologies, with an emphasis on key technological breakthroughs and opportunities, providing a comprehensive perspective for the next steps in research and real-vehicle applications of low-temperature heating technologies.
  • Dynamics Modeling and Stability Analysis of Cooperatively Towing Articulated Heavy-duty Vehicle System
    ZHANG Ning, WANG Haotan, ZHANG Qianchen, SHAO Liang, WANG Cheng, LI Pu, YIN Guodong
    Journal of Mechanical Engineering. 2025, 61(22): 133-142. https://doi.org/10.3901/JME.2025.22.133
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    As a new type of heavy-duty equipment for large cargo transportation, the cooperative traction articulated heavy-duty vehicle（CTA-HDV） is composed of a front and a rear traction unit connected to the cargo through an articulated device. Compared with traditional heavy-duty vehicles, its modeling and stability analysis are more difficult. A dynamic modeling method and stability analysis scheme for CTA-HDV system in the horizontal plane is proposed. In terms of system modeling, based on kinematic and dynamic analysis, the dynamic coupling relationship at each articulated point is analyzed, and a 4-degree-of-freedom single-track model of the cooperative traction articulated vehicle is established. In terms of stability analysis, first, the handling stability of CTA-HDV system is analyzed by independently defining the understeering gradient of traction unit 1 and traction unit 2. The influence of vehicle parameters on the understeering gradient of the CTA-HDV system is studied. The results show that the relative position of the center of mass of traction unit 1 and the relative position of the articulated point between traction unit 1 and the intermediate rigid body have the greatest influence on the understeering gradient of the system. When is adjusted from 0.3 to 0.6, the understeering gradient of the system decreases by approximately 79%. When is adjusted from 0.6 to 1.2, the understeering gradient of the system increases by approximately 86%. Secondly, combined with the dynamic stability analysis method of articulated vehicles, the dynamic critical speed of the CTA-HDV system is studied, and it is found that the dynamic critical speed of the CTA-HDV system is around 100 km/h. The influence of structural parameters on the dynamic stability of the system is also analyzed. This study provides a theoretical basis for the safety design of the CTA-HDV system.
  • Anti-slip Control of High-speed Trains Assisted by Electromagnetic Actuators
    MIAO Yuhao, LING Liang, ZHANG Heng, ZHAI Wanming
    Journal of Mechanical Engineering. 2025, 61(22): 143-154. https://doi.org/10.3901/JME.2025.22.143
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    The operation efficiency and the anti-slip control are critical issues of high-speed trains with the maximum vehicle speed is increased and the operation scenarios are diversified. The existing anti-slip control strategies tend to avoid wheel slippage by reducing the traction/braking torque, which results in a decrease of traction/braking capacity. Electromagnetic actuators, such as linear eddy current brakes and boosters, can induce vertical/longitudinal electromagnetic forces with the rail and are often equipped in the next generation trains to improve traction/braking capacity. In order to improve the traction/braking efficiency while solving the problem of wheel slippage, the electromagnetic actuator-assisted anti-slip control algorithm is proposed, in which the electromagnetic actuators is used to assist traction/braking on the basis of the optimal adhesion control. Based on the theory of vehicle-track coupled dynamics theory, the high-speed train-track coupled dynamics model equipped with electromagnetic actuators is established. The effects of this control strategy on the traction/braking performance and the wheel/rail dynamic interactions of high-speed trains under complex contact conditions are simulated and discussed. The results show that the proposed control strategy can remain the longitudinal creepage around the optimal control threshold, the electromagnetic actuators can increase the wheel/rail vertical force and thus improve the wheel/rail adhesion performance, and the non-adhesive longitudinal braking force can be provided under the braking condition. The maximum adhesion utilization is ensured and the traction/braking force is improved at the same time. Compared with the traditional anti-slip control methods, the electromagnetic actuator-assisted anti-slip control strategy can effectively improve the traction/braking performance of high-speed trains under low adhesion contact conditions.
  • Effect of Valve Core Speed on the Characteristics of Cavitation Flow during Fuel Pressure Relief
    LIANG Yuxiu, LI Yikai, LIU Hui
    Journal of Mechanical Engineering. 2025, 61(22): 155-166. https://doi.org/10.3901/JME.2025.22.155
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    To obtain the influence of valve core speed on the cavitation and pressure characteristics during the pressure relief process of the high-pressure fuel, a visualization experiment was conducted to validate a three-dimensional numerical calculation model. Based on the validated model, numerical calculations were conducted to study the cavitation flow during the opening process of the solenoid valve at different valve core speeds. The results show that the cavitation in the throttling section and downstream is caused by flow separation and jet entrainment, respectively. Moreover, at the same valve lift, higher valve core speeds result in more vapor at the throttling section, and the influence of valve core speed decreases as the valve lift increases. When the valve lift is less than 0.08 mm, increasing valve core speed leads to a decrease in downstream vapor volume at the same valve lift. When the valve lift is greater than 0.08 mm, a gradually weakening periodic vortex cavitation appears above the stroke stop, and the higher the speed of the valve core, the stronger the vortex cavitation. Additionally, the pressure fluctuations at the throttling section and downstream both originate from changes in total vapor volume fraction. The pressure in the throttling section exhibits attenuated fluctuations when the valve lift is less than 0.04 mm, and both frequency components of the fluctuations increase linearly with the valve core speed. The downstream pressure fluctuations occur when the valve core stroke is less than 0.06 mm, and with increasing valve core speed, the pressure peak increases.
  • Fast Simulation Research on Air Brake Systems of Long Freight Heavy Haul Trains
    GUO Shun, CHI Maoru, JIANG Yiping, LUO Yun
    Journal of Mechanical Engineering. 2025, 61(22): 167-175. https://doi.org/10.3901/JME.2025.11.167
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    The simulation model of the heavy-haul train air brake system is too complex to simulate slowly. In order to solve the problem, fast simulation method has been proposed. First, in the AMESim software, a simplified model is created based on the pressure characteristics of the 120-1 air brake valve. Secondly, the simulation model of air brake system established by parallel method is compared with the simulation model of air brake system established by traditional method. The simulation results show that the simulation time of the parallel method is at least 50% less than that of the traditional method. The longer the train formation is, the more complex the model is, the more obvious the simulation acceleration effect of the parallel method is, and the simulation time is reduced by up to 94%. Finally, the air brake system model of 20 000 tons heavy haul train is established by parallel method. The simulation results are compared with the test results to verify the accuracy of the simulation model. The single valve model is simplified and the air brake system model is established by parallel method, which reduces the state variables of the air brake system model of the heavy haul train and improves the simulation speed. It provides a new fast simulation method for the air brake system of the heavy haul train.
  • Lithium Plating Evaluation Method for Li-ion Batteries Based on Simplified P2D Model
    XIONG Rui, LI Xinggang
    Journal of Mechanical Engineering. 2025, 61(22): 176-188. https://doi.org/10.3901/JME.2025.22.176
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    Fast charging is an inevitable demand for the rapid development of lithium-ion batteries. However, during the fast charging process, when lithium ions fails to intercalate promptly into the graphite anode, it is easy to experience “lithium plating”, which seriously affects its durability and safety. Lithium plating online detection is a necessary means to improve the safety of fast charging batteries. Therefore, this paper selects 5 solid liquid particle points to characterize the potential distribution and simplify the P2D electrochemical model based on the porous electrode theory of batteries. The diffusion process of lithium ions in the solid phase particles and liquid phase inside the battery is discretized and solved separately. Lithium plating is evaluated based on the potential difference between the solid and liquid phases on the negative electrode surface. Qualitative analysis of lithium plating is carried out through scanning electron microscopy microscopic morphology observation and energy spectrum analysis. It is proposed to use the product of the peak appearance time and peak height of the relaxation voltage differential curve after charging as the validation parameter for indirect quantitative verification of the estimated lithium evolution amount. The model validation results under different temperature and magnification conditions indicate that the estimation error of the validation parameters for lithium plating in this model is less than 15%, which can achieve rapid plating of lithium evolution in lithium-ion batteries.
  • Comparative Assessment of Curving Performance in Active Steering and Forced Steering Bogies
    TIAN Shiqiao, LUO Xiangping, XIAO Chunyu, ZHOU Jinsong, GONG Dao, ZHAO Zengchuang
    Journal of Mechanical Engineering. 2025, 61(22): 189-197. https://doi.org/10.3901/JME.2025.22.189
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    The curving performance of a rail vehicle may be significantly enhanced by employing either active or forced steering bogies. Nevertheless, the transient dynamics at the transition curve differ between these two types of steering bogies due to their distinct steering mechanisms. Moreover, as both active and forced steering bogies alter the structure and physical topology of a conventional bogie suspension, the manner in which the same dynamic parameters influence curving performance might also exhibit discrepancies. To address these questions, active and forced steering vehicle dynamics models have been established in this study, followed by an analysis of the curving performance of both vehicles on two typical curves. Findings have revealed that a geometric inertia lag is experienced by the forced-steering bogie, thereby diminishing its curving performance during transitions curve. If the response lag of the active steering system remains below one third of the vehicle pitch and the maximum speed of movement does not fall short of 6.5 mm/s, the curving performance of the active steering bogie has been shown to surpass that of the forced steering bogie. Then a sensitivity analysis method has been employed, with the wear number utilized as an indicator, to comprehensively contrast the influence patterns of key dynamic parameters on the curving performance of conventional, active steering, and forced steering bogies. Results have demonstrated that the wheelset steering behavior is decoupled from the primary suspension stiffness by active and forced steering bogies, thereby enabling the elimination of primary suspension stiffness constraints on curving performance during parametric design, which brings convenient to bogie design.
  • Multi-expert Learning Method for Autonomous Lane-changing Decision-making in Multi-scenario Highway Environments
    YAO Fuxing, LI Haoyu, LENG Jianghao, YANG Xiongji, SUN Chao
    Journal of Mechanical Engineering. 2025, 61(22): 198-210. https://doi.org/10.3901/JME.2025.22.198
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    The decision-making process of autonomous vehicles on highways involves a sequence of driving maneuvers aimed at improving safety and efficiency, which, however, results in considerable training time for the learning algorithm. This study proposes a multi-expert learning method（MELM） that integrates multiple actors（experts）, each trained using the soft actor-critic（SAC） algorithm under constraints derived from distinct sub-layer scenarios. Each sub-layer scenario is defined according to the distinct properties of the original training scenario. Each expert controls the vehicle in its corresponding sub-layer scenario and is integrated via a classifier that identifies the applicable sub-scenario. As a result, the MELM significantly reduces the model’s training time by 62.19% compared to a single SAC model, while also improving driving safety and efficiency, attributed to a remarkable reduction in the training difficulty of SAC. The proposed MELM is compared against several state-of-the-art methods under representative driving scenarios. Simulation results show a 27.06% improvement in driving efficiency compared to the single SAC model, along with high safety performance characterized by zero collision and off-road incidents across 100 testing episodes（～100 000 timesteps）. Furthermore, the adaptability of MELM is validated through simulation in a variety of scenarios with different condition settings.
  • Study on Aerodynamic Drag Forces and Economics of 400 km/h High-speed Train with Different Streamline Lengths
    ZHOU Zhi, LI Tian, DAI Zhiyuan, XIANG Zerui, ZHANG Jiye
    Journal of Mechanical Engineering. 2025, 61(22): 211-221. https://doi.org/10.3901/JME.2025.22.211
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    In order to analyze the influence of streamline length on aerodynamic drag of high-speed train, based on computational fluid dynamics, the aerodynamic drag distribution characteristics of 400 km/h high-speed trains running on open lines are numerically simulated, the aerodynamic drag of train models with different streamline lengths is predicted. The reliability of the numerical simulation is verified by the wind tunnel test. Under the condition of the same length of the whole train, the influence of the streamline length of the head and tail car on the aerodynamic drag of the streamlined head, non-streamlined car body and bogie is studied. The length of the streamline is 10-15 m. The economic benefit relationship between the positive benefit of aerodynamic drag reduction and the negative benefit of passenger space reduction caused by the increase of streamline length is discussed. The results show that the resistance of the streamlined area of the head car is positively correlated with the ratio of its surface area to the streamline length. The resistance per meter in the non-streamlined area of the head car decreases gradual to the central area of the train, and the resistance per meter of the middle car decreases slowly to the direction of the tail car. The resistance per meter of the non-streamlined part of the tail car gradually converges; the streamline resistance of the tail car decreases with the length of the streamline. When the streamline length is about 13 m, the maximum benefit of 49.88 yuan/km is achieved, and the aerodynamic drag of 700 N is reduced, the benefit is optimal.
  • Rail Corrugation State Assessment Method Based on Train Interior Vibration and Noise Response
    WANG Yang, XIAO Hong, ZHANG Zhihai, YE Libin, JIN Feng, FANG Shuwei
    Journal of Mechanical Engineering. 2025, 61(22): 222-236. https://doi.org/10.3901/JME.2025.22.222
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    To establish a mechanism for mapping the relationship between interior train vibration and noise response and the state of the line rail surface corrugation, the dynamic time warping algorithm（DTW） is applied to synchronize vibration or noise signals with rail surface corrugation signals. The adaptive wavelet time-frequency analysis（AWTA） method is used to reveal the influence of rail corrugation on interior train vibration and noise in both the time and frequency domains. A mapping relationship between train interior vibration and noise and line rail corrugation state is constructed by the K-means clustering algorithm and custom windowed Pearson coefficients. A new method is proposed to evaluate rail corrugation state based on interior train vibration or noise response. The results show that the main frequencies of train interior noise and vertical floor vibration are primarily caused by rail corrugation. Specifically, the main frequencies of train interior noise are distributed in the range of 400-1 200 Hz, and the main frequencies of vertical floor vibration are distributed in the range of 300-1 000 Hz. The Pearson coefficients of train interior noise and inner and outer rail corrugation of the curve are around 0.82 and 0.62, respectively. Additionally, the Pearson coefficients of train interior floor vertical vibration and inner and outer rail corrugation of the curve are around 0.81 and 0.72, respectively. The rail corrugation state can be evaluated by the Noise Index and Vibration Index. The results are consistent with the measured data in the field. These indices can characterize the wavelength and amplitude of rail corrugation and provide a new method for identifying subway rail corrugation.
  • Fatigue Reliability Evaluation of Bogie Frame Considering Nonlinear Cumulative Damage Model Modification
    XIAO Qian, HUANG Wenlong, CHEN Daoyun, SUN Shouguang, LI Qiang, SHI Xiaoling
    Journal of Mechanical Engineering. 2025, 61(22): 237-249. https://doi.org/10.3901/JME.2025.22.237
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    In order to evaluate the fatigue reliability of a high-speed train bogie frame, based on the results of correlation analysis, some key measuring points on the frame were selected for line test. After collecting the measured dynamic stress of the line, the one-dimensional stress spectrum was compiled through the rain-flow counting process. The establishment process of Corten-Dolan and Manson-Halford nonlinear damage theoretical models is introduced respectively, and the models are modified by considering the interaction between loads and loading order. Based on the extended factor method, the measured extreme stress value is inferred, and the probability density distribution function of each measuring point is fitted based on the measured stress spectrum. The stress spectrum of all measuring points is extended to the whole life period. On this basis, the Corten-Dolan nonlinear model with high evaluation accuracy is screened out. Levenberg-Marquardt optimization regression algorithm was used to optimize the parameters. Based on the equivalent damage theory, the equivalent stress calculation formula under the nonlinear theory is derived, and the measured stress spectrum is substituted into the corresponding formula to analyze and calculate the equivalent stress at each measuring point. Combined with the S-N curves under three survival rates, the fatigue life of two kinds of frame materials is analyzed and compared. The results show that the fatigue life of the bogie frame can be prolonged by using SMA material at the weakest point of the frame.
  • Electromechanical Hydraulic Composite Control for Regenerative Braking of Single Motor Failure in Distributed Drive Electric Vehicles
    ZHANG Lipeng, LIU Yifan, LIU Shuaishuai, REN Changan, GAO Mingze, FAN Xiaojian
    Journal of Mechanical Engineering. 2025, 61(22): 250-261. https://doi.org/10.3901/JME.2025.22.250
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    In the regenerative braking of distributed drive electric vehicles on a long slope, the failure of one side motor can significantly weaken the braking strength and cause deviation due to imbalanced braking on both sides. Although cutting off the braking torque of the opposite side motor and actively compensating hydraulic braking can ensure the braking efficiency of the vehicle, it is impossible to correct deviation and continue to feedback energy. To solve the above problems, a new electromechanical hydraulic composite control method is explored based on the invented distributed/centralized dual-mode coupling drive system and electro-hydraulic braking system. Firstly, the feasibility of using the dual-mode coupling drive system for regenerative braking after a single motor failure is analyzed; Then, the vehicle dynamics modeling and controller design are conducted, and a model predictive control method combined with vector control to address the issue of poor precision in composite brake control is proposed; Finally, the composite control effect is verified through the hardware in the loop simulation. The research results indicate that, in addition to torque truncation and hydraulic compensation control, differential drive using the non-failed motor can ensure braking safety after the braking failure of one side motor. Afterwards, switching the two motors distributed drive to a single motor centralized drive can continue to perform regenerative braking and ensure the expected braking performance. The proposed electromechanical hydraulic composite control improves control accuracy by 64.83%, and the braking energy recovery value by 58.70%, effectively ensuring vehicle braking safety and energy recovery capability.
  • Motion and Deposition Characteristics of Snow Particles in Crosswind Environment for Bogie Region
    LAN Hong, ZHANG Jiye, CAI Lu, FAN Yongqi
    Journal of Mechanical Engineering. 2025, 61(22): 262-270. https://doi.org/10.3901/JME.2025.22.262
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    To investigate the snow accumulation in the bogie region of high-speed trains operating in cold climates, this study established a bogie and simplified body model of the train and used the Euler-Lagrange method to study snow particle motion and deposition characteristics under crosswind conditions. The results showed that crosswinds increased the frictional velocity on the bogie surface and the shear forces acting on snow particles, reducing the probability of stable deposition. Crosswind carries a large amount of snow particles out of the bogie region from the bottom of the train, reducing the amount of snow particles that rise near the wheelset and enter the bogie region. As the crosswind speed increases, the ratio of the upward movement speed of the snow particles to the crosswind speed decreases, resulting in a reduction in the amount of snow accumulation in the bogie region. During the process where snow particles flow from the windward side through the bottom of the bogie to the leeward side and then expand and flow out of the bogie region, a large number of snow particles collide with the surface on the leeward side. Moreover, the airflow on the leeward side is obstructed by the components on the windward side, and the shear force on the snow particles on the leeward side is relatively small, making it easy for snow to accumulate.
  • Design Optimization Method for Low-pressure-loss and Short-path Additive Manufactured Flow Channel
    YAO Jing, LI Mandi, ZHANG Xikun, GUO Qi, LI Xiang, ZHANG Hao
    Journal of Mechanical Engineering. 2025, 61(22): 271-281. https://doi.org/10.3901/JME.2025.22.271
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    The hydraulic channel is an important carrier for carrying pressure and transmitting power in hydraulic system. However, it has problems such as a large weight, a big volume, multiple process holes, and significant pressure losses, which seriously affect the power-to-weight ratio of the hydraulic system. Therefore, a combined algorithm using the rapid-exploration random tree（RRT） algorithm and a greedy algorithm is proposed to establish the shortest path for multi-directional irregular connecting area hydraulic flow channels based on addictive manufacture method. Subsequently, an adjoint optimization method is applied to the shortest path channels based on pressure loss for surface sensitivity adjoint optimization. Finally, selective laser melting technology is employed to fabricate the shortest path channels with low pressure loss, and a pressure loss testing platform is constructed to validate the reduction of pressure loss. Results show that the optimized final flow channel axis path is shortened by 49.6%, with smooth oil flow and reduced range along with intensity of vortex structures inside the channel of an electro-hydrostatic actuator（EHA）. Additionally, experiments demonstrate that the average pressure drop of the final flow channel decreases by 75.04% under different flow conditions. Research findings provide new insights for the optimization design of additive manufactured hydraulic flow channels.
  • Study on Heat Transfer Characteristics of Cover-plate Cavity in Pre-swirl System of Aircraft Engine
    MA Jiale, LIU Gaowen, WU Shuai, KONG Xiaozhi, LIN Aqiang
    Journal of Mechanical Engineering. 2025, 61(22): 282-293. https://doi.org/10.3901/JME.2025.22.282
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    The cover-plate cavity is the main heat exchange component in the pre-swirl system and has a significant impact on its performance. This study first studies the heat transfer mechanism inside the cover plate cavity through numerical calculations, and then conducts heat transfer experiments on the pre-swirl system using a new measurement method based on the Newton’s law of cooling formula, to verify the rationality of the numerical results. The study mainly analyzes the radial distribution characteristics of the heat transfer coefficient and Nusselt number on the turbine disk wall surface in the cover plate cavity. The results show that the heat transfer on the turbine disk wall surface is mainly affected by the mainstream impact, and the effect of swirling flow is relatively small. The pressure ratio is strongly correlated with the mainstream impact, while the rotational Mach number is strongly correlated with the swirling flow. Changing the operating conditions essentially changes the weight of the influence of the mainstream and swirling flow on heat transfer parameters. The numerical results and experimental results have deviations of less than 10%. From the experimental results, when the pressure ratio is constant, increasing the rotational Mach number from 0.27 to 0.64 increases the average heat transfer coefficient by 11.1% to 23.2%; when the rotational Mach number is constant, increasing the pressure ratio from 1.05 to 1.15 increases the average heat transfer coefficient by 44.7%～60.5%. The research results of this study can provide a design basis for the structural design of pre-swirl systems.
  • Synchronous Control of a Dual-drive Motion Platform Based on Adaptive Compensation of Synchronous Position Error
    SHI Yixuan, WU Xing, MENG Kai, ZHANG Hangying, LOU Peihuang
    Journal of Mechanical Engineering. 2025, 61(22): 294-305. https://doi.org/10.3901/JME.2025.22.294
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    The synchronization error of a dual-drive motion platform leads to decreased positioning accuracy and increased frictional perturbation. To address these problems, a synchronous control method based on adaptive compensation of dual-motor tracking error is proposed for the dual-drive motion platform. Firstly, the models of linear motors are systematically established and the friction perturbation force caused by the synchronization error is analyzed. Then, an adaptive synchronous control architecture is constructed for the dual-drive motion platform. A selective compensation strategy of real-time synchronous error is proposed for the motor with weak tracking performance. Moreover, a synchronous position controller is devised by combining single-axis position command tracking and synchronous position error compensation. This controller is used to provide the speed control command while both the single-axis tracking accuracy and dual-axis synchronous performance are considered. Finally, the synchronous control simulation and experiment are conducted on a dual-drive motion platform. PID control algorithm is implemented in the loops of position control and speed control, respectively, and the control performances of several synchronous control strategies are compared. The results of simulation and experiment show that the proposed adaptive synchronous control strategy obviously outperforms the parallel synchronous control strategy. Compared with the cross-coupling control strategy, this designed control strategy can not only improve the position tracking accuracy of each motor remarkably, but also enhance the position synchronization performance of dual motors.
  • Energy-saving Characteristics of the Swing System in a Large Electric Excavator Driven by an Electro-hydraulic Hybrid System
    CHENG Jie, WANG Huijie, QUAN Long, HUANG Jiahai, HUANG Weinan, XIA Lianpeng, HAO Huimin, YANG Fei
    Journal of Mechanical Engineering. 2025, 61(22): 306-316. https://doi.org/10.3901/JME.2025.22.306
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    Each working cycle of hydraulic excavator includes two swing actions, and frequent swing acceleration and braking result in a lot of overflow loss and throttling loss. Aiming at the problem that the existing energy saving technology of excavator swing system can not solve the problem of eliminating throttling loss and recycling and utilizing braking energy at the same time, a hybrid driving swing system is proposed, which uses permanent magnet synchronous motor as the main power source to drive the swing system of the vehicle, and the hydraulic motor-accumulator recycle and utilize the braking kinetic energy. This system effectively eliminates the throttling loss of the original hydraulic excavator through the multi-way valve, and recycles and utilizes the braking kinetic energy in the braking process. Based on the direct torque control of series motor, the control strategy that the start of swing process is accelerated by the motor and the hydraulic motor, and the braking process is braked by the hydraulic motor alone is realized. The research shows that compared with the original hydraulic excavator swing system, the peak power of the power source of the large electric excavator swing system can be reduced by 24%-32%, and the system energy consumption can be reduced by 14.1%-50.5%.
  • Research on Power System Matching of Super Large Electro-hydraulic Excavator
    CHEN Junxiang, GAO Chunying, KONG Xiangdong, LI Zhi, AI Chao
    Journal of Mechanical Engineering. 2025, 61(22): 317-328. https://doi.org/10.3901/JME.2025.22.317
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    In addressing the issue of pressure fluctuation at the pump outlet caused by engine speed drop during heavy load rapid loading for ultra-large electric-hydraulic excavators, taking the example of the boom-raising action, a study is conducted on the dynamic matching characteristics among the engine, main pump, and load. Mathematical models are established for the pump-controlled hydraulic cylinder, equivalent load force, and engine speed drop. Factors affecting the dynamic matching between the engine, variable pump, and load are analyzed. A torque-speed compound coordinated control strategy is proposed: the engine speed drop value is converted into a stall compensation torque value; the sum of the stall compensation torque value and the pump’s natural torque value are subjected to fuzzy PID control with deviations between the sum and the set ideal torque, as well as deviations between the actual speed and the set ideal speed, resulting in torque compensation and speed compensation currents. The larger of these currents is then employed for variable pump displacement compensation control. Experimental results demonstrated that under torque-speed dual control, the proportion of control stall compensation torque ranged from 10% to 35%. Hydraulic pump displacement fluctuation improved by 58%, and pump outlet pressure fluctuation improved by over 30%, thereby enhancing the operational performance of mining hydraulic excavators.
  • Pressure/Flow Ripple Characteristics and Experiment of the Integrated Energy Recovery-pressure Boost Device for Seawater Desalination
    YIN Fanglong, LUO Hao, NIE Songlin, YANG Yousheng, JI Hui, MA Zhonghai
    Journal of Mechanical Engineering. 2025, 61(22): 329-341. https://doi.org/10.3901/JME.2025.22.329
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    Energy recovery devices is a core component of reverse osmosis desalination systems, which significantly reduce water production energy and costs. The output flow quality of the device greatly affects reverse osmosis membrane performance, lifespan, and system stability. A lumped parameter model is presented for axial piston booster pump（APBP） in integrated energy recovery-pressure boosting device（IERPBD）, incorporating cavitation effects. Following ISO 10767-1-2015, a flow ripple test bench is constructed, and tests are conducted at the outlet of IERPBD. The source flow ripple and source impedance of APBP are derived based on theoretical methods, and the actual flow ripple and pressure ripple at the outlet of the device under different operating conditions are calculated. The variation patterns of flow ripple and pressure ripple under different working conditions have been identified:the average flow and average pressure rise as the rotation speed escalates; and it has been observed that flow ripple and pressure ripple also tend to escalate with the increase in rotation speed, but a reduction is noted at 1 700 r/min. The experimental results show that the maximum RMSE for the pressure characteristic curve does not exceed 0.121, and for the flow characteristic curve it remains below 0.538. The close agreement between the measured and simulated data provides a theoretical basis for optimizing the design of IERPBD to improve flow quality, and offers practical guidance for the application of energy recovery devices in seawater desalination.
  • Self-oscillating Fire Nozzle Flow Field Prediction Based on Reduced Order Prediction Model
    YUAN Xiaoming, LIU Cunfei, XIAO Haoyang, SHEN Binghan, XU Xinyu, ZHANG Lijie
    Journal of Mechanical Engineering. 2025, 61(22): 342-354. https://doi.org/10.3901/JME.2025.22.342
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    As the core component of the fire water jet system, the self-excited oscillating fire nozzle is suitable for eliminating most solid fires, and has the advantages of simple structure, high efficiency and low cost. The numerical simulation method can be used to calculate the flow field and obtain high precision results, but the calculation time is long and the calculation amount is large. The reduced order prediction model is an effective means to reduce the dimension of the flow field, realize flow field reconstruction and predict the flow field distribution. Therefore, taking the self-oscillating fire nozzles as the research object, a reduced order model based on encoder and proper orthogonal decomposition is proposed, and a long short-term memory networks and a deep neural network are used as reasoners to carry out the pulse mechanism analysis, feature extraction and reconstruction, timing prediction and pulse impact force analysis of the nozzle flow field. The prediction results show that the average relative error of the prediction of nozzle outflow field is 7.02%, that of internal flow field is 7.20%, and that of pulse jet pressure is 3.25%. The experimental results show that the minimum impulse force error between the prediction model and the test is 7.74% and the maximum impulse force error is 5.65%. The minimum pressure error of numerical simulation and test is 3.14%, and the maximum pressure error is 6.72%. The research of this project can provide a way to predict the nozzle flow field.
  • Pressure Margin Controllable Pre-compensated Load Sensing System with Variable Speed-fixed Displacement Pumps for Electric Construction Machinery
    LIN Yuanzheng, LIN Tianliang, LI Zhongshen, MIAO Cheng, CHEN Qihuai, ZHAO Heng, SHI Jiarong
    Journal of Mechanical Engineering. 2025, 61(22): 355-369. https://doi.org/10.3901/JME.2025.22.355
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    The development of electrification and intelligence of construction machinery has put forward higher requirements for energy saving and maneuverability of load sensing system. Aiming at the problems of the conventional load sensing system, such as the lack of anti-flow saturation function of pre-compensated type, the extra energy consumption of post-compensated type, and the fixed setting of the pressure margin, a pressure margin controllable pre-compensated load sensing system with variable speed-fixed displacement pumps is proposed, and the variable speed-pressure margin regulation and anti-flow saturation control strategies are further designed, and simulation and experimental studies are carried out. The results show that,① the proposed system has good anti-flow saturation characteristics;② the proposed system can be operated at different pressure margins to obtain variable flow gains to avoid the system from entering flow saturation, and the effective control stroke of the main spool has been improved to have better fine-tuning and flow control characteristics compared with the LUDV system;③ The proposed system eliminates additional commutation throttling losses and reduces orifice throttling losses compared to the LUDV system, resulting in a reduction in system energy consumption of 6.3% to 13.7% at different actuator speed conditions.
  • Simulation and Experimental Analysis of Flow Distribution Performance of the Micro Piston Pump
    BA Jinlei, JIANG Zhiwen, WU Defa, CUI Yan, LIU Yinshui
    Journal of Mechanical Engineering. 2025, 61(22): 370-382. https://doi.org/10.3901/JME.2025.22.370
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    It is an innovative idea to realize the decentralized and independent control of oil reservoir exploitation and finally realize the intelligent control of oil field exploitation by using the micro hydraulic system to drive oil field cementing slip sleeve separately in sections. The existing micro hydraulic pump is difficult to meet the requirements due to the extremely narrow layout space. A single piston micro pump with valve distribution structure（hereinafter referred to as micro pump） is proposed, whose maximum outer diameter is only 16 mm. The miniaturization design of piston pump can not rely on the reduction design of the existing conventional pump. Therefore, the structure coefficient ratio is proposed as a new characterizing parameter. The lumped parameter simulation model of micro pump flow characteristics is established to study the sensitivity of micro pump flow distribution performance to different influencing parameters. The performance test platform of the micro pump was built to study the pressure and flow characteristics of the micro pump under different suction conditions. The results show that when the initial closed volume decreases from 0.12 mL to 0.04 mL（corresponding to the structural coefficient ratio changes from 6C to 2C）, the volume efficiency of the micro pump increases from 83.5% to 92.97%. At the same time, increasing the inlet pressure of the pump can effectively enhance the suction capacity of the micro pump, thereby improving the distribution efficiency of the micro pump.
  • Study on the Contact Model of Clad Rolling Process and Deformation Characteristics of the Rolling Zone
    LI Zhiqiang, ZHANG Mingze, GUO Baoqi, CHEN Peng, WANG Tao, HUANG Qingxue
    Journal of Mechanical Engineering. 2025, 61(22): 383-397. https://doi.org/10.3901/JME.2025.22.383
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    Clad rolling is a rapid, efficient, and environmentally friendly method for producing composite plates, with significant potential for widespread application. The contact between the plate and the roll, as well as between plates, is a critical factor influencing the deformation and bonding strength of composite plates during the rolling process. To address the complex nonlinear contact issues inherent in clad rolling, a contact model was developed using the Mortar method to discretize the contact interfaces and the Lagrange multiplier method to enforce contact constraints. This model simulates the interactions between roll and plate, as well as between plates themselves. By interpolating the Lagrange multipliers with dual basis functions, the finite element stiffness matrix is simplified. Finally, a three-dimensional finite element simulation of the Cu/Al clad rolling process was conducted based on this contact model. The model has been verified to have high accuracy in predicting plate thickness and rolling force. The contact model can simulate the contact parameters on the contact interface. The results show that the contact interface between the aluminum plate and the roll, as well as the copper plate and the roll, is primarily characterized by sliding friction, whereas the contact interface between the copper plate and the aluminum plate is mainly characterized by stick friction. By simulating the clad rolling process under different reduction rates, the effects of the reduction rate on the neutral point and the cross shear zone were revealed, as well as the pattern of changes in the contact force at the plate interface with the reduction rate. The results indicate that as the reduction rate increases and the distance from the center of the plate decreases, the value of xN/xL decreases, and the increase in reduction rate causes a change in the direction of frictional forces on both sides of the cross shear zone. On the contact interface between the plates, the peak positions of pressure and frictional force gradually move away from the outlet as the reduction rate increases.
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CN 31-2023/U
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