A wireless high-frequency anemometer instrumentation system for field measurements

Guoqing Huang,Liuliu Peng,Yanwen Su,Haili Liao,Mingshui Li 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.20 No.6

Field measurement of wind characteristics is of great significance for the wind engineering community. High-frequency anemometers such as ultrasonic anemometers are widely used to obtain the high-frequency fluctuating wind speed time history. However, conventional instrumentation systems may suffer from low efficiency, non-real time transmission and higher maintenance cost, and thus are not very appropriate in the field measurement of strong winds in remote areas such as mountain valleys. In order to improve the field measurement performance in those remote areas, a wireless high-frequency anemometer instrumentation system for field measurement has been developed. In this paper, the architecture of the proposed instrumentation system, and measured data transmission and treatment will be presented firstly. Then a comparison among existing instrumentation systems and the proposed one is made. It shows that the newly-developed system has considerable advantages. Furthermore, the application of this system to the bridge site located in the mountain valley is discussed. Finally, typical samples of measured data from this area are presented. It can be expected that the proposed system has a great application potential in the wind field measurement for remote areas such as the mountainous or island or coastal area, and hazardous structures such as ultra-voltage transmission tower, due to its real-time transmission, low cost and no manual collection of data and convenience.

Predicting of tall building response to non-stationary winds using multiple wind speed samples

Guoqing Huang,Xinzhong Chen,Haili Liao,Mingshui Li 한국풍공학회 2013 한국풍공학회지 Vol.17 No.2

Non-stationary extreme winds such as thunderstorm downbursts are responsible for many structural damages. This research presents a time domain approach for estimating along-wind load effects on tall buildings using multiple wind speed time history samples, which are simulated from evolutionary power spectra density (EPSD) functions of non-stationary wind fluctuations using the method developed by the authors’ earlier research. The influence of transient wind loads on various responses including time-varying mean, root-mean-square value and peak factor is also studied. Furthermore, a simplified model is proposed to describe the non-stationary wind fluctuation as a uniformly modulated process with a modulation function following the time-varying mean. Finally, the probabilistic extreme response and peak factor are quantified based on the up-crossing theory of non-stationary process. As compared to the time domain response analysis using limited samples of wind record, usually one sample, the analysis using multiple samples presented in this study will provide more statistical information of responses. The time domain simulation also facilitates consideration of nonlinearities of structural and wind load characteristics over previous frequency domain analysis.

Numerical study for downburst wind and its load on high-rise building

Guoqing Huang,Weizhan Liu,Qiang Zhou,Zhitao Yan,Delong Zuo 한국풍공학회 2018 Wind and Structures, An International Journal (WAS Vol.27 No.2

3D simulations based on an impinging jet were carried out to investigate the flow field of a steady downburst and its effects on a high-rise building by applying the SST k-ω turbulence model. The vertical profile of radial wind speed obtained from the simulation was compared with experimental data and empirical models in order to validate the accuracy of the present numerical method. Then wind profiles and the influence of jet velocity and jet height were investigated. Focusing on a high-rise building, the flow structures around the building, pressure distributions on the building surfaces and aerodynamic forces were analyzed in order to enhance the understanding of wind load characteristics on a high-rise building immersed in a downburst.

Numerical study for downburst wind and its load on high-rise building

Huang, Guoqing,Liu, Weizhan,Zhou, Qiang,Yan, Zhitao,Zuo, Delong Techno-Press 2018 Wind and Structures, An International Journal (WAS Vol.27 No.2

3D simulations based on an impinging jet were carried out to investigate the flow field of a steady downburst and its effects on a high-rise building by applying the SST k-${\omega}$ turbulence model. The vertical profile of radial wind speed obtained from the simulation was compared with experimental data and empirical models in order to validate the accuracy of the present numerical method. Then wind profiles and the influence of jet velocity and jet height were investigated. Focusing on a high-rise building, the flow structures around the building, pressure distributions on the building surfaces and aerodynamic forces were analyzed in order to enhance the understanding of wind load characteristics on a high-rise building immersed in a downburst.

Predicting of tall building response to non-stationary winds using multiple wind speed samples

Huang, Guoqing,Chen, Xinzhong,Liao, Haili,Li, Mingshui Techno-Press 2013 Wind and Structures, An International Journal (WAS Vol.17 No.2

Non-stationary extreme winds such as thunderstorm downbursts are responsible for many structural damages. This research presents a time domain approach for estimating along-wind load effects on tall buildings using multiple wind speed time history samples, which are simulated from evolutionary power spectra density (EPSD) functions of non-stationary wind fluctuations using the method developed by the authors' earlier research. The influence of transient wind loads on various responses including time-varying mean, root-mean-square value and peak factor is also studied. Furthermore, a simplified model is proposed to describe the non-stationary wind fluctuation as a uniformly modulated process with a modulation function following the time-varying mean. Finally, the probabilistic extreme response and peak factor are quantified based on the up-crossing theory of non-stationary process. As compared to the time domain response analysis using limited samples of wind record, usually one sample, the analysis using multiple samples presented in this study will provide more statistical information of responses. The time domain simulation also facilitates consideration of nonlinearities of structural and wind load characteristics over previous frequency domain analysis.

A wireless high-frequency anemometer instrumentation system for field measurements

Huang, Guoqing,Peng, Liuliu,Su, Yanwen,Liao, Haili,Li, Mingshui Techno-Press 2015 Wind and Structures, An International Journal (WAS Vol.20 No.6

Field measurement of wind characteristics is of great significance for the wind engineering community. High-frequency anemometers such as ultrasonic anemometers are widely used to obtain the high-frequency fluctuating wind speed time history. However, conventional instrumentation systems may suffer from low efficiency, non-real time transmission and higher maintenance cost, and thus are not very appropriate in the field measurement of strong winds in remote areas such as mountain valleys. In order to improve the field measurement performance in those remote areas, a wireless high-frequency anemometer instrumentation system for field measurement has been developed. In this paper, the architecture of the proposed instrumentation system, and measured data transmission and treatment will be presented firstly. Then a comparison among existing instrumentation systems and the proposed one is made. It shows that the newly-developed system has considerable advantages. Furthermore, the application of this system to the bridge site located in the mountain valley is discussed. Finally, typical samples of measured data from this area are presented. It can be expected that the proposed system has a great application potential in the wind field measurement for remote areas such as the mountainous or island or coastal area, and hazardous structures such as ultra-voltage transmission tower, due to its real-time transmission, low cost and no manual collection of data and convenience.

Research on corrosion behavior of A6N01S-T5 aluminum alloy welded joint for high-speed trains

Guoqing Gou,Nan Huang,Hui Chen,Hongmei Liu,Aiqin Tian,Zhicheng Guo 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.5

"For high speed trains, safety is of utmost importance. Salt fog corrosion, intergranular corrosion tests were employed to observe the corrosion behavior of welded joint of A6N01S-T5 aluminum alloy of high-speed trains. Tensile strength and hardness changed after corrosion was tested. The micro morphologies were observed by metalloscope and laser confocal scanning microscope (LCSM). The corrosion loss and corrosion loss ratio were also investigated. The results showed that the heat affected zone (HAZ) was the most sensitive to corrosion in welded joint in the salt fog corrosion test. The potential of the corrosion of the intermetallic compound on the surface was different from the Al matrix potential, which easily generated corrosion micro-batteries that generated the corrosion pit. The weld zone was the most sensitive to corrosion in the welded joint in the intergranular corrosion test, because much corrosion produced an intermetallic phase such as CuAl2, MgZn2, Mg5Al8, which formed the deficient Cu or Mg zone potential. The potential is low, which acted as an anode and corroded. The residual stress test on the weld of the A6N01S-T5 of the W1 of the exterior surface of roof of high speed train showed there was distributed high tensile stress and compressed stress in the weld zone, HAZ zone and matrix zone. The defects will spread under the high stress and make the corrosion become severe."

Sequence Impedance Modeling and Frequency Characteristic Analysis of MMC-based HVDC

Tong Huang,Xin Chen,Guanghui Li,Guoqing He 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Modular multilevel converter (MMC) has emerged as a preferred technology for high-voltage dc (HVDC) transmission, while many HVDC-MMC projects have been reported resonance problems. The existing researches show that stability of a HVDC-grid system is decided by both the sequence impedance characteristic of HVDC-MMC and power grid, and due to coupling effect, the power grid impedance will also impact the HVDCMMC impedance characteristic. Multi-harmonic linearization method will be adopted in this paper to develop a HVDC-MMC analytical sequence impedance model. Then the developed model is used to illustrate the effect of the power control loop as well as the bandwidth of other controllers on HVDC-MMC impedance characteristic. Finally, based on the sequence impedance model considering coupling effect, the influence of HVDC-MMC bandwidth on the system stability will be analyzed as well.

Structural Mechanical Characteristics of a Large Bolted Beam Reaction System and Its Modified Calculation Method

Feng Huang,Ban Zhang,Xingchen Liu,Jinyang Xiang,Guoqing Wan,Miaodi Qu 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.1

The primary error sources of engineering design for bolted beam reaction system with large size are mainly from the deformation of structure, mechanical behavior of connection joints. In addition, the simplifi ed calculation method of bolted connection has not formed a unifi ed understanding. A vertical static load test was carried out in the laboratory, and the deformation laws of the reaction beam were analyzed to obtain the mechanical characteristics of the connection joints by controlling the defl ection of the reaction beam. The composite eff ect coeffi cient k l of the variable section panel structure was introduced to the theoretical solution of the defl ection of the variable cross-section beam. Simultaneously, the fi nite element method was employed to establish the detailed model of the beam reaction system. The mechanical behavior of the reaction beam and the bolted joint are extensively studied, and the simplifi ed method of bolted joint is improved. The bolted connection is simplifi ed as a semi-rigid joint, and then the theoretical formula is proposed to calculate the defl ection and deformation of the beam structure under bolted connection. The defl ection and deformation of the reaction beam by the test and theoretical formula are consistent. The results show that the theoretical formula can well calculate the defl ection and deformation of structure members under bolted connection.

Efficient buffeting analysis under non-stationary winds and application to a mountain bridge

Yanwen Su,Guoqing Huang,Ruili Liu,Yongping Zeng 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.2

Non-synoptic winds generated by tornadoes, downbursts or gust fronts exhibit significant non-stationarity and can cause significant wind load effect on flexible structures such as long-span bridges. However, conventional assumptions on stationarity used to evaluate the structural wind-induced vibration are inadequate. In this paper, an efficient frequency domain scheme based on fast CQC method, which can predict non-stationary buffeting random responses of long-span bridges, is presented, and then this approach is applied to evaluate the buffeting response of a long-span suspension bridge located in a complex mountainous wind environment as an example. In this study, the data-driven method based on one available measured wind speed sample is firstly presented to establish non-stationary wind models, including time-varying mean wind speed, time-varying intensity envelope function and uniformly modulated fluctuating spectrum. Then, a linear time-variant (LTV) system based on the proposed scheme can be generally applied to calculate the non-stationary buffeting responses. The effectiveness and accuracy of the proposed scheme are verified through Monte Carlo time domain simulation implemented in ANSYS platform. Also, the transient effect nature of the bridge responses is further illustrated by comparison of the non-stationary, quasi-stationary and steady-state cases. Finally, buffeting response analysis with traditional stationary treatment (10 min constant mean plus stationary wind fluctuation) is performed to illustrate the importance of the non-stationary characteristics embedded in original wind speed samples.