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Analysis of the Temperature Characteristics of High-speed Train Bearings Based on a Dynamics Model and Thermal Network Method

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 351-363页

作者： Baosen Wang yongqiang liu Bin Zhang Wenqing Huai School of Traffic and Transportation Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China Department of Electrical Engineering University of South CarolinaColumbia 29201USA Taiyuan Vehicle Depot of Daqin Railway Co. Ltd.Taiyuan 030000China

High-speed trains often use temperature sensors to monitor the motion state of ***,the temperature of bearings can be affected by factors such as weather and ***,it is necessary to analyze in detail the relationship between the bearing temperature and influencing *** this study,a dynamics model of the axle box bearing of high-speed trains is *** model can obtain the contact force between the rollers and raceway and its change law when the bearing contains outer-ring,inner-ring,and rolling-element *** on the model,a thermal network method is introduced to study the temperature field distribution of the axle box bearings of high-speed *** this model,the heat generation,conduction,and dispersion of the isothermal nodes can be *** results show that the temperature of the contact point between the outer-ring raceway and rolling-elements is the *** relationships between the node temperature and the speed,fault type,and fault size are analyzed,finding that the higher the speed,the higher the node *** different fault types,the node temperature first increases and then decreases as the fault size *** effectiveness of the model is demonstrated using the actual temperature data of a high-speed *** study proposes a thermal network model that can predict the temperature of each component of the bearings on a high-speed train under various speed and fault conditions.

关键词： High-speed train Axle box bearing Temperature characteristics Thermal network method

Establishment of Dynamic Model for Axle Box Bearing of High-Speed Trains Under Variable Speed Conditions

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 340-351页

作者： yongqiang liu Baosen Wang Bin Zhang Shaopu Yang School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Trafc and Transportation Shijiazhuang Tiedao UniversityShijiazhuang 050043China College of Engineering and Computing University of South CarolinaColumbiaSouth Carolina 29208USA State Key Laboratory of Mechanical Behavior and System Safety of Trafc Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

In this study,a dynamic model for the bearing rotor system of a high-speed train under variable speed conditions is *** contrast to previous studies,the contact stress is simplifed in the proposed model and the compensation balance excitation caused by the rotor mass eccentricity *** angle iteration method is used to overcome the challenge posed by the inability to determine the roller space position during bearing *** simulation results show that the model accurately describes the dynamics of bearings under varying speed profles that contain acceleration,deceleration,and speed oscillation *** order ratio spectrum of the bearing vibration signal indicates that both the single and multiple frequencies in the simulation results are consistent with the theoretical *** on bearings with outer and inner ring faults under various operating conditions are performed to verify the developed model.

关键词： Variable speed conditions High-speed train Bearing model Angle iteration Order ratio spectrum

Improving maize seed protein content and nitrogen-use efficiency by a teosinte asparagine synthetase

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Molecular Plant 2023年第3期16卷 497-499页

作者： yongqiang liu Chengcai Chu State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijingChina Guangdong Laboratory for Lingnan Modern Agriculture College of AgricultureSouth China Agricultural UniversityGuangzhouChina Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China Ministry of Agriculture and Rural AffairsSouth China Agricultural University.GuangzhouChina

From the earliest farming civilization,artificial selection continuously improves the critical agronomic traits for easier cultivation,higher yield,and better nutrient quality during crop *** this process,genetic diversity of modern crops might be largely lost due to bottleneck effect with relative relaxed selection pressure(Doebley et al.,2006).To this end,the wild ancestors of modern crops,with their abundant genetic diversity,act as valuable pools for modern crop improvement.

关键词： crops content relaxed

Dynamic analysis of axle box bearings on the high-speed train caused by wheel-rail excitation

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维普期刊数据库

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 441-460页

作者： Qiaoying MA Shaopu YANG yongqiang liu Baosen WANG Zechao liu State Key Laboratory of Mechanical behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Transportation Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China

To explore the impact of wheel-rail excitation on the dynamic performance of axle box bearings,a dynamic model of the high-speed train including axle box bearings is ***,the dynamic response characteristics of the axle box bearing are *** investigation focuses on the acceleration characteristics of bearing vibration under excitation of track irregularities and wheel *** addition,experiments on both normal and faulty bearings are conducted separately,and the correctness of the model and some conclusions are *** to the research,track irregularity is unfavorable for bearing fault detection based on resonance *** the same speed conditions,the acceleration peak of bearing is inversely proportional to the length of the wheel flat and directly proportional to its *** paper will contribute to a deeper understanding of the dynamic performance of axle box bearings.

关键词： high-speed train track irregularity wheel flat dynamic simulation

Characteristics and factors that influenced damage to dams in the M_s 8.0 Wenchuan earthquake

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Earthquake Engineering and Engineering Vibration 2011年第3期10卷 349-358页

作者： Jing Liping Liang Haian Li yongqiang liu Chunhui Institute of Engineering Mechanics China Earthquake Administration Harbin 150080 China

Based on raw data from dams damaged in the Wenchuan earthquake, including many that were severely damaged, characteristics and factors that influenced the damage are discussed in this paper. Findings from this study include： severely damaged dams were densely distributed along the seismologic fault; small dams, especially small earth-rock dams, had the most serious damage that was caused by a variety of factors; the most serious damage was caused by seismic waves; damage was aggregated by aftershocks; and the extent of the damage patterns increased with the seismic intensity. Damage patterns varied in different intensity zones and cracking was the most common type of damage. Most of the dams had a good base with relatively high bearing capacity, and the walls of the earth-rock dams were mostly of clay soil. This type of base and body material mitigated some of the damage to dams. Reservoir maintenance and other factors also have a significant impact on the seismic safety of the dam. Finally, some recommendations to reduce seismic damage to dams are proposed.

关键词： seismic damage dam characteristic of damage to dams influencing factors Wenchuan earthquake seismologic fault earth-rock dams

Research on hunting stability and bifurcation characteristics of nonlinear stochastic wheelset system

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Applied Mathematics and Mechanics(English Edition) 2023年第3期44卷 431-446页

作者： Peng WANG Shaopu YANG yongqiang liu Pengfei liu Xing ZHANG Yiwei ZHAO State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Traffic and Transportation Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050043China

A stochastic wheelset model with a nonlinear wheel-rail contact relationship is established to investigate the stochastic stability and stochastic bifurcation of the wheelset system with the consideration of the stochastic parametric excitations of equivalent conicity and suspension *** wheelset is systematized into a onedimensional(1D)diffusion process by using the stochastic average method,the behavior of the singular boundary is analyzed to determine the hunting stability condition of the wheelset system,and the critical speed of stochastic bifurcation is *** stationary probability density and joint probability density are derived *** on the topological structure change of the probability density function,the stochastic Hopf bifurcation form and bifurcation condition of the wheelset system are *** effects of stochastic factors on the hunting stability and bifurcation characteristics are analyzed,and the simulation results verify the correctness of the theoretical *** results reveal that the boundary behavior of the diffusion process determines the hunting stability of the stochastic wheelset system,and the left boundary characteristic value cL=1 is the critical state of hunting ***,stochastic D-bifurcation and P-bifurcation will appear in the wheelset system,and the critical speeds of the two kinds of stochastic bifurcation decrease with the increase in the stochastic parametric excitation intensity.

关键词： stochastic wheelset system stochastic average method singular boundary hunting stability stochastic Hopf bifurcation

Establishment of the thermo-mechanical coupling model of axle box bearings with track irregularity excitation and analysis of its temperature characteristics

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Applied Mathematics and Mechanics(English Edition) 2024年第11期45卷 1965-1986页

作者： Min WANG Shaopu YANG yongqiang liu Yanhong CHEN Kai ZHANG State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China School of Traffic and Transportation Shijiazhuang Tiedao UniversityShijiazhuang050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang050043China CRRC Tangshan Co. Ltd.Tangshan063000Hebei ProvinceChina China Water Resources Beifang Investigation Designand Research Co.Ltd.Tianjin300222China

As an important component of the running gear of high-speed trains,axle box bearings can cause lubricating grease failure and damage to bearing components under continuous high-temperature operation,which will affect the normal operation of highspeed ***,bearing temperature is one of the key parameters to be monitored in the online monitoring system for *** on the thermal network method,this paper establishes a thermal network model for the axle box bearing,considering the radial thermal deformation of the double-row tapered roller bearing components caused by the oil film characteristics and the temperature variations of the lubricating grease.A thermo-mechanical coupling model for the grease-lubricated double-row tapered roller axle box bearing of high-speed trains with track irregularity excitation is *** correctness of the model is verified using the test bench data,and the temperature of the bearing at different rotational speeds,loads,fault sizes,and ambient temperatures are investigated.

关键词： axle box bearing thermal network method temperature rotational speed

Spatiotemporal variation of surface albedo and its influencing factors in northern Xinjiang, China

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Journal of Arid Land 2023年第11期15卷 1315-1339页

作者： YUAN Shuai liu yongqiang QIN Yan ZHANG Kun College of Geography and Remote Sensing Sciences Xinjiang UniversityUrumqi 830046China Xinjiang Key Laboratory of Oasis Ecology Xinjiang UniversityUrumqi 830046China

Surface albedo is a quantitative indicator for land surface processes and climate modeling,and plays an important role in surface radiation balance and climate *** this study,by means of the MCD43A3 surface albedo product developed on the basis of Moderate Resolution Imaging Spectroradiometer(MODIS),we analyzed the spatiotemporal variation,persistence status,land cover type differences,and annual and seasonal differences of surface albedo,as well as the relationship between surface albedo and various influencing factors(including Normalized Difference Snow Index(NDSI),precipitation,Normalized Difference Vegetation Index(NDVI),land surface temperature,soil moisture,air temperature,and digital elevation model(DEM))in the north of Xinjiang Uygur Autonomous Region(northern Xinjiang)of Northwest China from 2010 to 2020 based on the unary linear regression,Hurst index,and Pearson's correlation coefficient *** with the random forest(RF)model and geographical detector(Geodetector),the importance of the above-mentioned influencing factors as well as their interactions on surface albedo were quantitatively *** results showed that the seasonal average surface albedo in northern Xinjiang was the highest in winter and the lowest in *** annual average surface albedo from 2010 to 2020 was high in the west and north and low in the east and south,showing a weak decreasing trend and a small and stable overall *** cover types had a significant impact on the variation of surface *** annual average surface albedo in most regions of northern Xinjiang was positively correlated with NDSI and precipitation,and negatively correlated with NDVI,land surface temperature,soil moisture,and air *** addition,the correlations between surface albedo and various influencing factors showed significant differences for different land cover types and in different *** be specific,NDSI had the largest influence on surface albedo,follow

关键词： surface albedo MCD43A3 Hurst index random forest(RF)model geographical detector(Geodetector) Normalized Difference Snow Index(NDSI) northern Xinjiang

Sensitivity of Atlantic Meridional Overturning Circulation to the Dynamical Framework in an Ocean General Circulation Model

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Journal of Meteorological Research 2017年第3期31卷 490-501页

作者： Xiaolan LI yongqiang YU Hailong liu Pengfei LIN State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences College of Earth Science University of Chinese Academy of Sciences

The horizontal coordinate systems commonly used in most global ocean models are the spherical latitude-longit- ude grid and displaced poles, such as a tripolar grid. The effect of the horizontal coordinate system on Atlantic meri- dional overturning circulation （AMOC） is evaluated by using an OGCM （ocean general circulation model）. Two ex- periments are conducted with the model---one using a latitude-longitude grid （referred to as Latl） and the other us- ing a tripolar grid （referred to as Tri）. The results show that Tri simulates a stronger North Atlantic deep water （NADW） than Lat_l, as more saline water masses enter the Greenland-Iceland-Norwegian （GIN） seas in Tri. The stronger NADW can be attributed to two factors. One is the removal of the zonal filter in Tri, which leads to an in- creasing of the zonal gradient of temperature and salinity, thus strengthening the north geostrophic flow. In turn, it decreases the positive subsurface temperature and salinity biases in the subtropical regions. The other may be associ- ated with topography at the North Pole, because realistic topography is applied in the tripolar grid while the latitude-longitude grid employs an artificial island around the North Pole. In order to evaluate the effect of the filter on AMOC, three enhanced filter experiments are carried out. Compared to Lat_l, an enhanced filter can also aug- ment NADW formation, since more saline water is suppressed in the GIN seas, but accumulated in the Labrador Sea, especially in experiment Lat_2 S, which is the experiment with an enhanced filter on salinity.

关键词： AMOC OGCM tripolar grid latitude-longitude grid zonal filter