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Defect Analysis and Innovation Design of Synchronizer for Clutchless Automatic mechanical Transmission

Chinese Journal of mechanical engineering 2022年第1期35卷 238-254页

作者： Lipeng Zhang Yunao Peng Haojie Yang Shaohua Li Hebei Key Laboratory of Special Delivery Equipment Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

The synchronizer is a key component of automatic mechanical transmission(AMT)equipped in electric vehicles,but the inertial lock-ring synchronizer(ILRS)commonly used there is not suitable especially for pure electric vehicles without a clutch because of big shift *** make the shifting process rapid and smooth,a new synchronizer named pressure-controllable friction ring synchronizer(PCFRS)was ***,the inevitable shortcoming of ILRS was verified by simulation and ***,the mechanical characteristics and advantages of the new synchronizer over ILRS were ***,the formulations describing the dynamic transmission based on the working mechanism of the PCFRS were ***,the shifting simulation results with PCFRS and ILRS based on the same operating conditions were compared and *** research shows that the PCFRS can meet the main shifting evaluation index of an AMT without complex control methods,as well as it takes only 0.2406 s to finish the comfortable and zero-speed-difference *** shifting quality of PCFRS is better than that of the *** lays a foundation for using the new synchronizer as a part of clutchless AMTs equipped in pure electric vehicles.

关键词： Electric vehicle Clutchless automatic mechanical transmission Inertial lock-ring synchronizer Pressure-controllable friction ring synchronizer mechanical characteristics Shifting quality

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Topology transition description of horseshoe vortex system in junctureflows with velocity characteristic lines

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Theoretical & Applied Mechanics Letters 2024年第6期14卷 540-547页

作者： Bo Hu Hua Zhang Ran Li Qingkuan Liu State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Engineering Mechanics Shijiazhuang Tiedao UniversityShijiazhuang 050043China Ministry-of-Education Key Laboratory of Fluid Mechanics School of Aeronautical Science and EngineeringBeihang University(BUAA)Beijing 100191China School of Civil Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Particle image velocimetry and numerical simulation results of juncture flows were analyzed to parametrically investigate topology transition. The vortex system evolutions from non-vortex to multi-vortex with variations in obstacle bluntness, obstacle width, flow velocity, and boundary layer thickness are discussed from the perspective of velocity characteristic lines. The velocity characteristic lines of u = 0, υ = 0, and ∇^(2) υ = 0 are adopted to describe the vortex system evolution. The motions of the characteristic lines with juncture flow parameters are described in detail, and the corresponding reflections of the vortex system patterns are illustrated. A panoramic picture of the development of velocity characteristic lines corresponding to the HSV topology transition from a non-vortex to a multi-vortex system with variations in the juncture flow parameter is established. Two methods for determining the attachment/separation pattern of the most upstream singularity are proposed. One method is based on the number of intersections of the u = 0 and υ = 0 velocity characteristic curve lines, and the other is based on the relative positions of the most upstream feet of the u = 0 and υ = 0 loop curves with both feet attached to the wall.

关键词： Juncture flow Topology transition Velocity characteristic lines

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Frost-resistant embankments with a novel ground source heat pump system

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Research in Cold and Arid Regions 2024年第6期16卷 292-301页

作者： TianFei Hu Li Wang TengFei Wang TieCheng Sun TianFeng Li State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuangHebei 050043China School of Civil Engineering Shijiazhuang Tiedao UniversityShijiazhuangHebei 050043China Key Laboratory of High-Speed Railway Engineering Southwest Jiaotong UniversityMinistry of EducationChengduSichuan 610031China

This study introduces a novel artificial heating technique aimed at addressing frost heave issues in embankments on frozen ground,offering a sustainable *** evaluations assessed various heating systems,including boilers,heat pumps,solar heaters,and electric heaters,focusing on their thermal performance and *** study subsequently designed and implemented a direct-expansion ground source heat pump(DX-GSHP)system as the primary heat source for embankment *** testing confirmed the DX-GSHP system's ability to maintain a heat-supply temperature above 40℃ and a heat-absorption temperature below -3.5℃,effectively extracting geothermal energy for transfer to the topsoil *** a demonstrated coefficient of performance(COP)of 3.49,the DX-GSHP system not only proves its energy efficiency but also suggests a potential role in reducing the strain on electricity supply *** of DX-GSHPs,with heating capacities ranging from 1.0 to 2.0 kW and spaced at intervals of 2.0-4.0 m,provides a rapid thermal response to frost heave in singletrack railway embankments,thereby potentially mitigating frost-induced damage in cold climate regions.

关键词： Frost heave Embankment Artificial heating Ground source heat pump Coefficient of performance

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evolution Rule of Wheel Tread Wear of High-Speed Train and its Influence on Dynamic Performance

Evolution Rule of Wheel Tread Wear of High-Speed Train and i...

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2024 IEEE International Conference on Sensing, Diagnostics, Prognostics, and control, SDPC 2024

作者： Wang, Peng Liu, Zhenkai Liu, Yongqiang Yang, Shaopu Cai, Yuqiang College of Mechanical Engineering North China University of Science and Technology Tangshan China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang China Safety of Traffic Engineering Structures Shijiazhuang Tiedao University State Key Laboratory of Mechanical Behavior and System Shijiazhuang China

ISBN: (纸本)9798350388855

To investigate the influence of wheel wear evolution on wheel-rail contact and dynamic performance of high-speed trains, taking a high-speed train as the research object, the wheel wear tracking test was carried out to analyze the evolution law of wheel wear with the running mileage. Using the wheel-rail contact geometric relationship and non-Hertz rolling contact theory, the influence of wheel wear on wheel-rail contact geometric characteristics and contact mechanical characteristics was calculated, and the wheel-rail matching performance under wear was analyzed. The vehicle model was established by UM software, and the influence of different wheel wear treads on the vehicle's dynamic performance in a lathing cycle was investigated. The results indicate that during the evolution of wheel profile, the distribution state of wheel-rail contact points changes. With the increase of wheel tread wear, the radius difference of wheel rolling circles increases, which is conducive to improving the curve passing performance of vehicles. The wear of wheel tread leads to the increase of vehicle transmissibility and the decrease of nonlinear critical speed. © 2024 IEEE.

关键词： Gear trains

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AFS/DYC control of In-Wheel Motor Drive Electric Vehicle With Adaptive Tire Cornering Stiffness 6

AFS/DYC Control of In-Wheel Motor Drive Electric Vehicle Wit...

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6th CAA International Conference on Vehicular control and Intelligence, CVCI 2022

作者： Li, Shaohua Yang, Zekun Shijiazhuang Tiedao University Behavior and System Safety of Traffic Engineering Structures State Key Laboratory of Mechanical Shijiazhuang China

ISBN: (数字)9781665453745

ISBN: (纸本)9781665453745

A linear tire model with constant conering stiffness does not guarantee the model accuracy, while a traditional nonlinear tire model has to face complicated parameter adjustment problems. In order to improve the adaptive capability of path tracking controller for a in-wheel motor drive electric vehicle (IDEV), the cornering stiffness is regarded as a time-varying parameter when tire sideslip angle increases. For the upper controller, the lateral tire force is estimated online based on square root cubature Kalman filter (SRCKF) to solve the cornering stiffness uncertainty. Then a prediction model of MPC with cornering stiffness modified is proposed to reduce the effect of model mismatch. For the lower controller, an active front steering control (AFS) and direct yaw moment control (DYC) based on integrated MPC is designed to track path and improve handling stability. The proposed control strategy is verified under extreme conditions through CarSim/Simulink simulation. It is shown that the strategy effectively improves the accuracy of path tracking and the stability of vehicle compared with the conventional MPC controller. © 2022 IEEE.

关键词： Tires

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Contact Analysis Between Rollers and Raceway of Axle Box Bearing Under Multi-source Fault 2nd

Contact Analysis Between Rollers and Raceway of Axle Box Bea...

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2nd International Conference of mechanical System Dynamics, ICMSD 2023

作者： Ma, Qiaoying Yang, Shaopu Liu, Yongqiang School of Transportation Shijiazhuang Tiedao University Shijiazhuang050043 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China

ISBN: (纸本)9789819980475

The axle box bearing is highly nonlinear and affected by external excitation factors during the service process, such as the running environment of the vehicle and wheel-rail excitations. Based on the coupling dynamics model of a high-speed train and axle box bearing, wheel tread damage and bearing outer ring fault were introduced in this paper. On this basis, the contact force between the roller and raceway of the bearing in the presence of multi-source faults was analyzed. In addition, the simulation of the vehicle running in tangent-line and curve-line conditions was carried out, and the evolution law of bearing contact force was further revealed through analysis. Through research, it is found that the curve-line running conditions have a significant impact on the bearing contact force. The following conclusions can be drawn from the analysis: If the wheel is normal, faulty bearings are more affected when running in a tangent-line, while normal bearings are more affected when running in a curve-line. The maximum difference between the tangent and curve conditions occurs in normal bearing of the longitudinal direction. If the wheel is defective, the distribution of contact force in curve-line running is close, with peak values of 251.77 kN. Meanwhile, the RMS of the fault bearing essentially stays the same in comparison to the normal bearing, so the vibration caused by a bearing fault is relatively weak when compared to the excitation caused by a wheel flat. When running in a curve, the contact force of the normal bearing in the longitudinal direction increases by a factor of about 74.69, with the largest growth range. The smaller the radius of the curve, the greater the influence of the contact force, and also the larger the fluctuation of the contact force between the roller and raceway, so that the probability of bearing fatigue damage greatly increases. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Railroads

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Model free optimization of building cooling water systems with refined action space

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Building Simulation 2023年第4期16卷 615-627页

作者： Qiaofeng Xiong Zhengwei Li Wenxia Cai Zhechao Wang School of Mechanical Engineering Tongji University ShanghaiChina Key Laboratory of Performance Evolution and Control for Engineering Structures of Ministry of Education Tongji UniversityShanghaiChina

Deep Q Network(DQN)is an efficient model-free optimization method,and has the potential to be used in building cooling water ***,due to the high dimension of actions,this method requires a complex neural ***,both the required number of training samples and the length of convergence period are barriers for real ***,penalty function based exploration may lead to unsafe actions,causing the application of this optimization method even more *** solve these problems,an approach to limit the action space within a safe area is proposed in this *** of all,the action space for cooling towers and pumps are separated into two ***,for each type of equipment,the action space is further divided into safe and unsafe *** a result,the convergence speed is significantly *** with the traditional DQN method in a simulation environment validated by real data,the proposed method is able to save the convergence time by 1 episode(one cooling season).The results in this paper suggest that,the proposed DQN method can achieve a much quicker learning speed without any undesired consequences,and therefore is more suitable to be used in projects without pre-learning stage.

关键词： building cooling water system cooling tower cooling water pump DQN controller convergence speed

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Research on Automatic Modeling Method for Railway Linear structures

Research on Automatic Modeling Method for Railway Linear Str...

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2023 International Conference on Remote Sensing, Mapping, and Geographic Systems, RSMG 2023

作者： Sun, Xiaohao Nie, Liangtao School of Transportation Shijiazhuang Tiedao University Shijiazhuang China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University School of Transportation Shijiazhuang China

ISBN: (纸本)9781510668898

The key point and difficulty in realizing the rapid modeling of railway line 3D scenes is the automatic modeling technology of railway line entity model. Parametric modeling of linear structures is the committed step to realize automatic modeling of railway line structure. According to the characteristics of linear structures in line structure, this paper proposes an automatic modeling method based on lofting modeling for railway line 3D scenes. First, construct the section template library of the line structure. Call the template according to certain rules. Then, through the lofting procedures, the automatic modeling of the linear structure is realized under the parameter drive. Finally, by developing applications driven control parameter values, automated modeling of railway linear structures was completed. Compared with the traditional 3D modeling methods, the modeling method of lofting can realize the automatic modeling of linear structures in long strip railway line more quickly. © 2023 SPIE.

关键词： 3D modeling

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Design and Wave Propagation Characterization of Starchiral Metamaterials

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Acta Mechanica Solida Sinica 2022年第2期35卷 215-227页

作者： Yajun Xin Han Wang Cong Wang Jinxin Yao Qian Ding Haoqiang Gao Shuliang Cheng Yongtao Sun Key Laboratory of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province Yanshan UniversityQinhuangdao 060000China Hebei Province Low-Carbon and Clean Building Heating Technology Innovation Center Yanshan UniversityQinhuangdao 060000China Department of Mechanics and Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin UniversityTianjin 300072China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Metamaterials with simple artificial topological properties made from industrially produced single-phase materials have extraordinary innovation and *** this paper,we investigated wave propagation characteristics of a hexastarchiral lattice metamaterial with periodic assemblies and used the finite element(FE)method to study the band gap ***,in order to understand the mechanism of band gaps,we discussed the mode shapes of unit cells and found that the bending of the ligament and the overall rotation have a high correlation with the generation of omnidirectional band *** relationships bet ween geometric parameters and band gap properties have also been systematically studied,which demonstrated that the band gaps of the proposed metamaterial could be reasonably predicted through the evolution of geometric ***,the transmission characteristics of finite sandwich panel structures composed of periodic unit cells were calculated to verify the correctness of the band gap simulation results,which proved that the proposed artificial metastructure has potential application value in vibration and noise reduction projects.

关键词： Hexastarchiral lattice metamaterials Band gap properties Finite element method Rotational resonance

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Energy harvesting and speed sensing with a hybrid rotary generator for self-powered wireless monitoring

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Acta Mechanica Sinica 2024年第9期40卷 116-130页

作者： Zhixia Wang Hongyun Qiu Xuanbo Jiao Wei Wang Qichang Zhang Ruilan Tian Dongxing Cao School of Mechanical Engineering Tianjin UniversityTianjin 300350China Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin 300350China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Mechanics Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China

Real-time onboard health monitoring systems are critical for the railway industry to maintain high service quality and operational ***,the issue with power supplies for monitoring sensors persists,especially for freight trains that lack onboard ***,we propose a hybrid piezoelectric-triboelectric rotary generator(HPT-RG)for energy harvesting and vehicle speed *** HPT-RG incorporates a rotational self-adaptive technique that softens the equivalent stiffness,enabling the piezoelectric non-resonant beam to surpass resonance limitations in a low-frequency *** experiments demonstrate the feasibility of using the HPT-RG as an energy harvesting module to collect the rotational energy of the freight rail transport and power the wireless temperature *** allow multiple monitoring in confined spaces on trains,a triboelectric sensing module is added to the HPT-RG to sense the operation speed and mileage of ***,the generator exhibits favorable mechanical durability under more than 600 h of official testing on the train bogie *** proposed HPT-RG is essential for creating a truly self-powered,maintenance-free,and zero-carbon onboard wireless monitoring system on freight railways.

关键词： Energy harvesting Speed sensing Rotational self-adaptive technique Low-frequency Self-powered wireless monitoring

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