Wind loads on a moving vehicle–bridge deck system by wind-tunnel model test

Yongle Li,Peng Hu,You-Lin Xu,Mingjin Zhang,Haili Liao 한국풍공학회 2014 Wind and Structures, An International Journal (WAS Vol.19 No.2

Wind-vehicle-bridge (WVB) interaction can be regarded as a coupled vibration system. Aerodynamic forces and moment on vehicles and bridge decks play an important role in the vibration analysis of the coupled WVB system. High-speed vehicle motion has certain effects on the aerodynamic characteristics of a vehicle-bridge system under crosswinds, but it is not taken into account in most previous studies. In this study, a new testing system with a moving vehicle model was developed to directly measure the aerodynamic forces and moment on the vehicle and bridge deck when the vehicle model moved on the bridge deck under crosswinds in a large wind tunnel. The testing system, with a total length of 18.0 m, consisted of three main parts: vehicle-bridge model system, motion system and signal measuring system. The wind speed, vehicle speed, test objects and relative position of the vehicle to the bridge deck could be easily altered for different test cases. The aerodynamic forces and moment on the moving vehicle and bridge deck were measured utilizing the new testing system. The effects of the vehicle speed, wind yaw angle, rail track position and vehicle type on the aerodynamic characteristics of the vehicle and bridge deck were investigated. In addition, a data processing method was proposed according to the characteristics of the dynamic testing signals to determine the variations of aerodynamic forces and moment on the moving vehicle and bridge deck. Three-car and single-car models were employed as the moving rail vehicle model and road vehicle model, respectively. The results indicate that the drag and lift coefficients of the vehicle tend to increase with the increase of the vehicle speed and the decrease of the resultant wind yaw angle and that the vehicle speed has more significant effect on the aerodynamic coefficients of the single-car model than on those of the three-car model. This study also reveals that the aerodynamic coefficients of the vehicle and bridge deck are strongly influenced by the rail track positions, while the aerodynamic coefficients of the bridge deck are insensitive to the vehicle speed or resultant wind yaw angle.

Sensorless IPMSM Control Based on an Extended Nonlinear Observer with Rotational Inertia Adjustment and Equivalent Flux Error Compensation

Yongle Mao,Jiaqiang Yang,Dejun Yin,Yangsheng Chen 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

Mechanical and electrical parameter uncertainties cause dynamic and static estimation errors of the rotor speed and position, resulting in performance deterioration of sensorless control systems. This paper applies an extended nonlinear observer to interior permanent magnet synchronous motors (IPMSM) for the simultaneous estimation of the rotor speed and position. Two compensation methods are proposed to improve the observer performance against parameter uncertainties: an on-line rotational inertia adjustment approach that employs the gradient descent algorithm to suppress dynamic estimation errors, and an equivalent flux error compensation approach to eliminate static estimation errors caused by inaccurate electrical parameters. The effectiveness of the proposed control strategy is demonstrated by experimental tests.

Aerostatic and buffeting response characteristics of catwalk in a long-span suspension bridge

Yongle Li,Dongxu Wang,Chupeng Wu,Xinzhong Chen 한국풍공학회 2014 Wind and Structures, An International Journal (WAS Vol.19 No.6

This study presents a comprehensive investigation of the aerostatic and buffeting response characteristics of a suspension bridge catwalk. The three-dimensional aerostatic response analysis was carried out taking into account the geometric nonlinearity and nonlinear dependence of wind loads on the angle of attack. The buffeting response analysis was performed in the time domain. The aerostatic and buffeting responses of the catwalk show strong coupling of vertical and lateral vibrations. The lateral displacement is the main component of the wind-induced static and buffeting response of the catwalk

High Shock-Resistant Design of Piezoresistive High-g Accelerometer

Yongle Lu,Zhen Qu,Jie Yang,Wenxin Wang,Wenbo Wang,Yu Liu 한국정보처리학회 2023 Journal of information processing systems Vol.19 No.2

To improve the shock-resistance of piezoresistive high-g accelerometer, we propose a design of piezoresistivehigh-g accelerometer. The accelerometer employs special-shaped proof masses system with a cross gap. Fourtiny sensing beams are bonded above the cross gap. The expression of the deformation, natural frequency anddamping is deduced, and the structural parameters are optimized. The accelerometer structure is simulated andverified by finite element method (FEM) simulation. The results show that the range of the accelerometer canreach 200,000 g, the natural frequency is 453.6 kHz, and the cross-axis sensitivity of X-axis and Y-axis is0.25% and 0.11%, respectively, which can apply to the measurement of high shock. Contrastively, the crossaxissensitivity of X-axis and Y-axis is respectively, reduced by 93.2% and 96.9%. The sensitivity of ouraccelerometer is 0.88 μV/g. It is of great value for the application of piezoresistive high-g accelerometer withhigh shock-resistance.

Wind-tunnel study of wake galloping of parallel cables on cable-stayed bridges and its suppression

Yongle Li,Mengxue Wu,Xinzhong Chen,Tao Wang,Haili Liao 한국풍공학회 2013 Wind and Structures, An International Journal (WAS Vol.16 No.3

Flexible stay cables on cable-stayed bridges are three-dimensional. They sag and flex in the complex wind environment, which is a different situation to ideal rigid cylinders in two-dimensional wind flow. Aerodynamic interference and the response characteristics of wake galloping of full-scale parallel cables are potentially different due to three-dimensional flows around cables. This study presents a comprehensive wind tunnel investigation of wake galloping of parallel stay cables using three-dimensional aeroelastic cable models. The wind tunnel study focuses on the large spacing instability range, addressing the effects of cable separation, wind yaw angle, and wind angle of attack on wake galloping response. To investigate the effectiveness of vibration suppression measures, wind tunnel studies on the transversely connected cable systems for two types of connections (flexibility and rigidity) at two positions (mid-span and quarter-span) were also conducted. This experimental study provides useful insights for better understanding the characteristics of wake galloping that will help in establishing a guideline for the wind-resistant design of the cable system on cable-stayed bridges.

Analysis and study of compact inductive power transfer systems for EV charging

Ai, Yongle,Hu, Xiaoqi,Li, Xing,Zhang, Xin The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.5

The double-sided LCC topology provides an efficient compensation method for electric vehicle (EV) wireless charging systems. However, the existence of two compensation coils results in an electric vehicle wireless charging device with a large volume, high power consumption, and low efficiency. To solve these problems, this paper proposes a wireless charging structure in which the compensation coils are separately integrated into the transmitting and receiving coils. First, the number of turns of the transmitting coil is optimized to maximize the coupling coefficient of the transmitting coil. Secondly, to minimize the redundant coupling effect, the relative placement of the compensation coils is studied. Based on the proposed coil integration method, it is possible to ignore the redundant coupling between the compensation coils and the transmitting and receiving coils. Then, the Ansys Maxwell and Ansys Twin Builder are used to build a joint simulation circuit to construct the proposed wireless charging system. Simulation and experimental results show that the system output power is 3.09 kW with a gap of 150 mm, and that the transmission efficiency is 95.49%. In addition, the integrated solution has a high transmission efficiency in the presence of front-to-back misalignment and vertical misalignment of electric vehicles.

Sensorless IPMSM Drives based on Extended Nonlinear State Observer with Parameter Inaccuracy Compensation

Mao, Yongle,Liu, Guiying,Chen, Yangsheng Journal of International Conference on Electrical 2014 Journal of international Conference on Electrical Vol.3 No.3

This paper proposed a novel high performance sensorless control scheme for IPMSM based on an extended nonlinear state observer. The gain-matrix of the observer has been derived by using state linearization method. Steady state errors in estimated rotor position and speed due to parameter inaccuracy have been analyzed, and an equivalent flux error is defined to represent the overall effect of parameter errors contributing to the wrong convergence of the estimated rotor speed as well as rotor position. Then, an online compensation strategy was proposed to limit the estimation errors in rotor position and speed. The effectiveness of the extended nonlinear state observer is validated through simulation and experimental test.

Sensorless IPMSM Control Based on an Extended Nonlinear Observer with Rotational Inertia Adjustment and Equivalent Flux Error Compensation

Mao, Yongle,Yang, Jiaqiang,Yin, Dejun,Chen, Yangsheng The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

Mechanical and electrical parameter uncertainties cause dynamic and static estimation errors of the rotor speed and position, resulting in performance deterioration of sensorless control systems. This paper applies an extended nonlinear observer to interior permanent magnet synchronous motors (IPMSM) for the simultaneous estimation of the rotor speed and position. Two compensation methods are proposed to improve the observer performance against parameter uncertainties: an on-line rotational inertia adjustment approach that employs the gradient descent algorithm to suppress dynamic estimation errors, and an equivalent flux error compensation approach to eliminate static estimation errors caused by inaccurate electrical parameters. The effectiveness of the proposed control strategy is demonstrated by experimental tests.

Wind loads on a moving vehicle-bridge deck system by wind-tunnel model test

Li, Yongle,Hu, Peng,Xu, You-Lin,Zhang, Mingjin,Liao, Haili Techno-Press 2014 Wind and Structures, An International Journal (WAS Vol.19 No.2

Wind-vehicle-bridge (WVB) interaction can be regarded as a coupled vibration system. Aerodynamic forces and moment on vehicles and bridge decks play an important role in the vibration analysis of the coupled WVB system. High-speed vehicle motion has certain effects on the aerodynamic characteristics of a vehicle-bridge system under crosswinds, but it is not taken into account in most previous studies. In this study, a new testing system with a moving vehicle model was developed to directly measure the aerodynamic forces and moment on the vehicle and bridge deck when the vehicle model moved on the bridge deck under crosswinds in a large wind tunnel. The testing system, with a total length of 18.0 m, consisted of three main parts: vehicle-bridge model system, motion system and signal measuring system. The wind speed, vehicle speed, test objects and relative position of the vehicle to the bridge deck could be easily altered for different test cases. The aerodynamic forces and moment on the moving vehicle and bridge deck were measured utilizing the new testing system. The effects of the vehicle speed, wind yaw angle, rail track position and vehicle type on the aerodynamic characteristics of the vehicle and bridge deck were investigated. In addition, a data processing method was proposed according to the characteristics of the dynamic testing signals to determine the variations of aerodynamic forces and moment on the moving vehicle and bridge deck. Three-car and single-car models were employed as the moving rail vehicle model and road vehicle model, respectively. The results indicate that the drag and lift coefficients of the vehicle tend to increase with the increase of the vehicle speed and the decrease of the resultant wind yaw angle and that the vehicle speed has more significant effect on the aerodynamic coefficients of the single-car model than on those of the three-car model. This study also reveals that the aerodynamic coefficients of the vehicle and bridge deck are strongly influenced by the rail track positions, while the aerodynamic coefficients of the bridge deck are insensitive to the vehicle speed or resultant wind yaw angle.

中国农村剩余劳动力的出路

Wang Yongle 서울행정학회 2007 서울행정학회 학술대회 발표논문집 Vol.- No.-

According to modern classical theory, modernization refers to industrialization and urbanization. It refers to the relationship between the urban areas and the: rural areas. In the process of modernization, the traditional rural areas are facing, a serious challenge: to survive or to ruin, to decline or to recover, to be abandoned or to be reconstructed...... Any country that walks toward the modernization must face and solve this "Hamlet" problem. The issue of Chinese rural areas and farmers is such a issue of social improvement which is considered in the background of the modernization. In the ancient times, it was agricultural society and agriculture was the most important industry. The majority of the populace is farmers. The balanced society based on the agricultural civilization runs under the rule of its own logic. As a result, the issue of Farmers, Rural Areas and Aagriculture Production didn't cause social land political problems. However, as the society improves, the modern industrial civilization factors such as cities, workers and industries turned out; then the problem of Farmers, Rural Areas and Agriculture Production relevant to the traditional civilization has become a social and political problem. Especially to China, as its mineralization process is activated by the crash of western industrial civilization, the problem of the rural areas and farmers became very intense. From the beginning of this century, as is greatly influenced by the western culture, this problem is becoming more and more conspicuous, it has become one of the most important problems that wait to be solved by the government. As a result, the research of the problem of the rural areas and farmers in 21th century is becoming very significant. Paying more attention to farmers, supporting the development of the agriculture production and rural. areas, is not only a realistic problem but also a strategy problem; it is not only a economical problem but also a political problem. Therefore, the issue about how to solve the problem of Farmers, Rural Areas and Agriculture Production has become a hot topic of Chinese governmental academic circles. This article aims to express my opinion on the problem of the surplus labor force.