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4th International Symposium on traffic Transportation and Civil Architecture, ISTTCA 2021

作者： Ding, Xiang Zhu, Yongquan Guo, Xiaolong Yun, Kai China Railway Fifth Survey and Design Institute Group Co. Ltd. Beijing102600 China Shijiazhuang Tiedao University State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Hebei Shijiazhuang050043 China School of Civil Engineering Shijiazhuang Tiedao University Hebei Shijiazhuang050043 China

ISBN: (纸本)9781665425926

In order to clarify the basic physical characteristics and swelling characteristics of mudstone along Yinlan high speed railway, the basic physical characteristics test and swelling test of mudstone were carried out based on the mudstone of Baotaishan tunnel. The test results show that: (1) the mudstone of Baotaishan tunnel is mainly composed of quartz, calcite and illite, and the content of viscous minerals is low;(2) The swelling deformation of mudstone changes with time in three typical stages: rapid growth stage, deceleration growth stage and stable stage. The mudstone swellings rapidly after encountering water, and the swelling deformation at 1h reaches more than 85% of the total deformation;(3) The swelling deformation of mudstone in Baotaishan tunnel is small, but the swelling force is 250.8kPa. The swelling load is considered in the tunnel design. The test results can provide basic data for the design and construction of swelling mudstone tunnel along Yinlan high speed railway. © 2021 IEEE.

关键词： Deformation

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Wheelset Bearing Fault Diagnosis Method Based on a Novel Parameter-Adaptive Vmd

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SSRN 2022年

作者： Li, Cuixing Liu, Yongqiang Liao, Yingying State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China School of Traffic and Transportation Shijiazhuang Tiedao University Shijiazhuang050043 China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China

The traditional parameter-adaptive VMD method uses an advanced meta-heuristic algorithm to determine the two key parameters of mode number and penalty factor adaptively, but this method has the deficiency of a long time-consuming. To solve this problem, a novel parameter-adaptive VMD method is proposed in this paper, which uses the PSO to optimize the initial center frequency and the penalty factor. The single-mode VMD has a strong convergence and can converge to the optimal center frequency as long as the initial center frequency is in the U-shaped range. With this characteristic of VMD, we propose an improved PSO. The correctness of the proposed method is verified by analyzing the fault signals of two sets of wheelset bearings. Compared with the traditional parameter-adaptive VMD method and the EEMD method, the results show that the proposed method has outstanding advantages in fault feature extraction and operation efficiency. © 2022, The Authors. All rights reserved.

关键词： Failure analysis

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Effect of Deformation Twinning on Microstructure Refinement of Fe-38mn Alloy During Friction Stir Processing

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SSRN 2022年

作者： Sang, Deli Xin, Xiaoli Fu, Ruidong Li, Yijun College of Materials Science and Engineering Shijiazhuang Tiedao University Hebei Shijiazhuang050000 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Hebei Shijiazhuang050043 China State Key Laboratory of Metastable Materials Science and Technology Yanshan University Hebei Qinhuangdao066004 China

The effect of deformation twinning on microstructure refinement was investigated for Fe-38Mn alloy during friction stir processing. It was proved that the friction stir processing microstructure of Fe-38Mn alloy was gradient distribution. The stir zone contained both recrystallized grains and fine deformed grains with average grain size of about 15 μm, and the proportion of twin boundaries in the deformed grain zone was up to 35%. Moreover, the cyclic multidirectional shear induced micro-shear bands and sub-grains with high density dislocations, as well as plentiful deformation twins. The microstructure refinement of Fe-38Mn alloy during friction stir processing resulted from the dynamic recrystallization mechanism and twinning mechanism. In addition, the cyclic multidirectional shear deformation enhanced the deformation twinning effect, so that the microstructure refinement process was completed quickly and effectively. The above works indicate a dynamic mechanism of microstructure refinement in term of the deformation twinning during friction stir processing. © 2022, The Authors. All rights reserved.

关键词： Binary alloys

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Dynamic performance of six-axle locomotive subjected to asymmetric brake shoe forces

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Journal of Central South University 2020年第9期27卷 2776-2791页

作者： LIU Peng-fei ZHANG Kai-long CAO Yun-qiang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China

To research the influence of asymmetric brake shoe forces(ABSF)induced by braking failure on the dynamic performance of six-axle locomotive,the static equilibrium model of three-axle bogie and dynamic model for locomotive are *** coupling vibration equations of axle hung motor and wheelset are *** the air braking,the influence mechanism of ABSF on the wheel-rail asymmetric motion and force characteristics are *** can be found that if the ABSF is applied in the front wheelset,all the wheelsets move laterally in the same *** the ABSF occurs in the middle or rear one,other wheelsets may move laterally towards the opposite *** motion amplitude and direction of all wheelsets strictly depend on the resultant moment of suspension yawing moment and brake shoe asymmetric *** the asymmetric braking,the free lateral gap of axle-box could increase the wheelset motion amplitude,but could not change the moving *** both the straight line and curve,the ABSF may lead to wheelset misaligning motion,intensify the wheel-rail lateral dynamic interaction and deteriorate wheel-rail contact *** for the steering wheelsets,the asymmetric braking increases the wheelset attack angle significantly,which forms the worst braking condition.

关键词： locomotive brake shoe force dynamic performance asymmetric braking wheel-rail contact

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Dynamic response analysis of the whole bridge based on vehicle-bridge coupling vibration

Dynamic response analysis of the whole bridge based on vehic...

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第八届国际振动工程会议

作者： Jing Liu Shaohua Li Jianying Ren Yu Zhang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University School of Mechanical Engineering Shijiazhuang Tiedao University Department of Engineering Mechanics Shijiazhuang Tiedao University

In order to study the dynamic responses of the bridge under the action of vehicles, a quarter vehicle model, considering multiple points tire-road contacting and a simply supported beam is coupled to establish a vehicle-bridge interaction(VBI) model. The analytical solutions are compared with the numerical solutions of VBI responses to verify the validity of the numerical method. The dynamic responses of each cross section of the bridge are analyzed when multiple vehicles are going through the bridge at a constant speed. The global maximum values of the dynamic deflection, the dynamic bending moment and the dynamic shear force of the bridge and the corresponding position on the bridge are obtained. The effect of vehicle speed and vehicle distance on the global maximum values is further analyzed. The results show that when a critical vehicle speed is reached, the global maximum values reach the maximum. At different vehicle speeds, the global maximum dynamic deflection occurs at the points near the mid-span, the global maximum dynamic bending moment occurs at the points within 9 m on the left and right sides of the mid-span,while the global maximum dynamic shear force occurs at the bridge end. When the distance between two vehicles is larger, the global maximum values are smaller. When the distance between two vehicles is up to a critical distance, the global maximum values will no longer decrease and are the same as the maximum values when only one vehicle travels on the bridge.

关键词： VBI Dynamic response analysis of the whole bridge based on vehicle-bridge coupling vibration

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Investigation on the reinforcement effect of a bedding slope affected by a landsliding block

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Arabian Journal of Geosciences 2022年第6期15卷 1-20页

作者： Zhang, Fei Yang, Tianhong Li, Lianchong Zhu, Xinping Key Laboratory of Roads and Railway Engineering Safety Control Shijiazhuang Tiedao University Ministry of Education Shijiazhuang China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang China Center of Rock Instability and Seismicity Research School of Resources and Civil Engineering Northeastern University Shenyang Liaoning China China Coal Technology and Engineering Group Shenyang Research Institute Fushun China

The south slope of Fushun west open-pit mine located in Northeast China is a high-deep rock slope. In the last few years, a landsliding block has gradually formed in the south slope. Owing to the effect of sliding force caused by the sliding block, some damage has occurred on the foundation of Kengkou refinery which constructed in the west of the south slope. To improve the stability of the refinery foundation, three group micro-pile structures were employed to cut off the drag of the sliding block and reinforce the refinery on the southwest slope. In this study, a comprehensive method combining the microseismic monitoring technique and numerical simulation method was used, the stability of the southwest slope was evaluated, and reinforcement mechanism was deeply analyzed. A microseismic monitoring system is established on-site to obtain useful information about the damage energy, location, and magnitude of the rocks in the southwest slope. Thus, the west boundary of the landslide in the south slope of the open-pit is determined. By analyzing the numerical results, the stress concentration is discovered mainly around the micro-pile structures and near the west boundary. After reinforcement, the displacement decrease in the south-north direction is apparent. To investigate the interaction mechanism between the micro-pile and the surrounding rock mass, a local 3D numerical model is employed to help understand auxiliary information about the stress state and stress redistribution induced by failure in the surrounding rock mass. It is shown that the reinforcement effect becomes more and more evident with the increase in the number of employed micro-piles. The numerical results and in situ GPS displacement monitoring data illustrate that the micro-pile structures have an excellent strengthening result in controlling the deformation of the slope. The comprehensive methodology provides an effective way to estimate the stability and the reinforcement effect of the slope und

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Design and Hydrodynamic Experiments of a Novel All-Speed Biomimetic Rudder-Controlled Autonomous Underwater Vehicle

Design and Hydrodynamic Experiments of a Novel All-Speed Bio...

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IEEE International Conference on Robotics and Biomimetics

作者： Tianbo Lan Jiang Ding Jingyu Li Fengran Xie Kai He Qiyang Zuo Guangxi Key Laboratory of Manufacturing System and Advanced Manufacturing Technology School of Mechanical Engineering Guangxi University Nanning China Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenzhen China State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi University Nanning China School of Artificial Intelligence Shenzhen Polytechnic University Shenzhen China

ISBN: (数字)9798331509644

ISBN: (纸本)9798331509651

This paper presents a novel biomimetic rudder-controlled autonomous underwater vehicle (BRCAUV) that is capable of operating at all speed range (i.e. including high, medium, low, and even zero speeds) for both wide-area cruising and localized fine observation tasks. This AUV integrates a top rudder, a propeller, and two-degree-of-freedom (DOF) biomimetic rudder wings on both sides of the aft section, enabling it to perform various tasks in a single underwater operation. These tasks include wide-area cruising at medium to high speeds and fine observation at low and even zero speeds. The prototype is equipped with a propeller, a biomimetic dorsal fin, two pectoral fins(i.e. two-DOF biomimetic rudder wings), and a buoyancy regulation system. At medium to high speeds, the AUV utilizes a combination of the propeller and pectoral fin movements for ascent and descent. At low or zero speeds, the biomimetic pectoral fins are used for complex maneuvers such as buoyancy adjustment, roll, and pitch. This paper develops a dynamic model of the pectoral fins based on quasi-steady theory, elucidating the principles of low-speed steering. Experimental were carried out and the results validate the prototype's low-speed steering capabilities, so that new approaches were presented to enhance the maneuverability, multifunctionality, and practicality for underwater vehicles.

关键词： Autonomous underwater vehicles Technological innovation Propellers Biomimetics Biological system modeling Robot kinematics Prototypes Buoyancy Turning Vehicle dynamics

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Design and Analysis of the Cooling Effect of the Temperature-Controlled Pile (Tcp) in Permafrost Regions

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SSRN 2022年

作者： Sun, Zhaohui Liu, Jiankun Hu, Tianfei You, Tian Fang, Jianhong School of Civil Engineering Sun Yat-sen University Southern Marine Science and Engineering Guangdong Laboratory Zhuhai519082 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Qinghai Research Institute of Transportation Xining810001 China

To accelerate the refreezing time of cast-in-place piles in permafrost regions and improve their long-term stability, this paper proposes a novel TCP based on solar refrigeration. The TCP consists of a solar power system (SPS), a vapor compression refrigeration system (VCRS), and a pile. Then, the cooling effect of TCP was carried out by the model test and the numerical simulation. The model test results show that both the evaporating temperature and the condensing temperature are positively correlated with the ambient temperature, but the coefficient of performance (COP) is negatively correlated with the ambient temperature. The numerical simulation results show the TCP can significantly shorten the refreezing time. The higher the mean annual ground temperature (MGAT), the more significant the acceleration effect. With the increase in the TCP working time, the pile wall permafrost temperature tends to be stable, and the cooling radius increases continuously. The TCP can restrain the degradation rate of the permafrost table, which can be further reduced by increasing the refrigeration power and the refrigeration tube space. The tangential freezing force between the frozen soil and the pile foundation is enhanced by the cooling effect of TCP and is stronger when it is close to the middle of the pile. The TCP bearing capacity is more than 1.5 times that of a traditional pile (TP). The effect of improving the bearing capacity of the pile foundation can be achieved by increasing the refrigeration power and refrigeration tube space. Therefore, TCP can be applied to pile engineering of high-speed railways and highways in permafrost regions. © 2022, The Authors. All rights reserved.

关键词： Piles

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Effect of fractional-order PID controller with displacement feedback on the dynamics of spur gear

Effect of fractional-order PID controller with displacement ...

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第八届国际振动工程会议

作者： Jingyu Hou Shaopu Yang Qiang Li Yongqiang Liu School of Mechanical Electronic and Control Engineering Beijing Jiaotong University State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University School of Mechanical Engineering Shijiazhuang Tiedao University

A torsional vibration model of spur gear is built up with considering the effect of the time-varying mesh stiffness, backlash and static transmission error. In order to reduce and control the level of vibration, the fractional-order calculus was introduced into the traditional proportional-integral-derivative(PID) control system and the nonlinear dynamic model of gear transmission based on fractional-order PID(FOPID) controller with displacement feedback is presented. The higher-precision approximate periodic solution of this system is derived by using the incremental harmonic balance method(IHBM). Finally, the influence of the coefficients and fractional order of each link of FOPID controller with displacement feedback on the meshing vibration characteristics of the gear transmission is analyzed in detail by means of amplitude-frequency response curve. Meanwhile, the response of the system with FOPID controller is compared with that of integer-order PID controller and without PID controller. The results show that the control performance of FOPID controller is apparently better than that of integer-order PID controller. Therefore, the FOPID controller with displacement feedback is applied to investigate nonlinear behavior of gear during the meshing, which would provide a certain theoretical basis and instruction for the control of vibration and noise in the mechanical transmission.

关键词： red Effect of fractional-order PID controller with displacement feedback on the dynamics of spur gear

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Speed following control of truck based on driver intention recognition 4

Speed following control of truck based on driver intention r...

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4th CAA International Conference on Vehicular Control and Intelligence, CVCI 2020

作者： Wang, Guiyang Li, Shaohua Wang, Hesen State Key Laboratory of Mechanical Behavior in Traffic Engineering Structure and System Safety Dept. Name of Organization Shijiazhuang050043 China

ISBN: (纸本)9781728184968

Autonomous emergency braking (AEB) system enables vehicles to avoid collisions or mitigate the damage. Due to large braking distance, a safety distance model on the basis of the vehicles driving state and the process of vehicle braking is established. The driver's reaction time and early warning vehicle speed following controller are established, and the predictive AEB algorithm based on the driver's operation intention is established. Finally, TruckSim-Matlab/Simulink co-simulation for the AEB control strategy is conducted. The simulation result shows that the proposed control strategy can hierarchically warn and automatically brake, which is effective. © 2020 IEEE.

关键词： MATLAB

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