Development of a dynamic sensing system for civil revolving structures and its field tests in a large revolving auditorium

Yaozhi Luo,Yanbin Shen,Pengcheng Yang,Feng Yu,Zhouneng Zhong,Jiangbo Hong 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.13 No.6

In civil engineering, revolving structures (RS) are a unique structural form applied in innovative architecture design. Such structures are able to revolve around themselves or along a certain track. However, few studies are dedicated to safety design or health monitoring of RS. In this paper, a wireless dynamic sensing system is developed for RS, and field tests toward a large revolving auditorium are conducted accordingly. At first, a wheel-rail problem is proposed: The internal force redistributes in RS, which is due to wheel-rail irregularity. Then the development of the sensing system for RS is presented. It includes system architecture, network organization, vibrating wire sensor (VWS) nodes and online remote control. To keep the sensor network identifiable during revolving, the addresses of sensor nodes are reassigned dynamically when RS position changes. At last, the system is mounted on a huge outdoor revolving auditorium. Considering the influence of the proposed problem, the RS of the auditorium has been designed conservatively. Two field tests are conducted via the sensing system. In the first test, 2000 people are invited to act as the live load. During the revolving process, data is collected from RS in three different load cases. The other test is the online monitoring for the auditorium during the official performances. In the end, the field-testing result verifies the existence of the wheel-rail problem. The result also indicates the dynamic sensing system is applicable and durable even while RS is rotating.

Development of a dynamic sensing system for civil revolving structures and its field tests in a large revolving auditorium

Luo, Yaozhi,Yang, Pengcheng,Shen, Yanbin,Yu, Feng,Zhong, Zhouneng,Hong, Jiangbo Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.13 No.6

In civil engineering, revolving structures (RS) are a unique structural form applied in innovative architecture design. Such structures are able to revolve around themselves or along a certain track. However, few studies are dedicated to safety design or health monitoring of RS. In this paper, a wireless dynamic sensing system is developed for RS, and field tests toward a large revolving auditorium are conducted accordingly. At first, a wheel-rail problem is proposed: The internal force redistributes in RS, which is due to wheel-rail irregularity. Then the development of the sensing system for RS is presented. It includes system architecture, network organization, vibrating wire sensor (VWS) nodes and online remote control. To keep the sensor network identifiable during revolving, the addresses of sensor nodes are reassigned dynamically when RS position changes. At last, the system is mounted on a huge outdoor revolving auditorium. Considering the influence of the proposed problem, the RS of the auditorium has been designed conservatively. Two field tests are conducted via the sensing system. In the first test, 2000 people are invited to act as the live load. During the revolving process, data is collected from RS in three different load cases. The other test is the online monitoring for the auditorium during the official performances. In the end, the field-testing result verifies the existence of the wheel-rail problem. The result also indicates the dynamic sensing system is applicable and durable even while RS is rotating.

Aero-elastic wind tunnel test of a high lighting pole

Yaozhi Luo,Yucheng Wang,Jiming Xie,Chao Yang,Yanfeng Zheng 한국풍공학회 2017 Wind and Structures, An International Journal (WAS Vol.25 No.1

This paper presents a 1:25 multi-freedom aero-elastic model for a high lighting pole at the Zhoushan stadium. To validate the similarity characteristics of the model, a free vibration test was performed before the formal test. Beat phenomenon was found and eliminated by synthesis of vibration in the X and Y directions, and the damping ratio of the model was identified by the free decay method. The dynamic characteristics of the model were examined and compared with the real structure; the similarity results were favorable. From the test results, the major along-wind dynamic response was the first vibration component. The along-wind wind vibration coefficient was calculated by the China code and Eurocode. When the peak factor equaled 3.5, the coefficient calculated by the China code was close to the experimental result while Eurocode had a slight overestimation of the coefficient. The wind vibration coefficient during typhoon flow was analyzed, and a magnification factor was suggested in typhoon-prone areas. By analyzing the power spectrum of the dynamic cross-wind base shear force, it was found that a second-order vortex-excited resonance existed. The cross-wind response in the test was smaller than Eurocode estimation. The aerodynamic damping ratio was calculated by random decrement technique and the results showed that aerodynamic damping ratios were mostly positive at the design wind speed, which means that the wind-induced galloping phenomenon is predicted not to occur at design wind speeds.

Aero-elastic wind tunnel test of a high lighting pole

Luo, Yaozhi,Wang, Yucheng,Xie, Jiming,Yang, Chao,Zheng, Yanfeng Techno-Press 2017 Wind and Structures, An International Journal (WAS Vol.25 No.1

This paper presents a 1:25 multi-freedom aero-elastic model for a high lighting pole at the Zhoushan stadium. To validate the similarity characteristics of the model, a free vibration test was performed before the formal test. Beat phenomenon was found and eliminated by synthesis of vibration in the X and Y directions, and the damping ratio of the model was identified by the free decay method. The dynamic characteristics of the model were examined and compared with the real structure; the similarity results were favorable. From the test results, the major along-wind dynamic response was the first vibration component. The along-wind wind vibration coefficient was calculated by the China code and Eurocode. When the peak factor equaled 3.5, the coefficient calculated by the China code was close to the experimental result while Eurocode had a slight overestimation of the coefficient. The wind vibration coefficient during typhoon flow was analyzed, and a magnification factor was suggested in typhoon-prone areas. By analyzing the power spectrum of the dynamic cross-wind base shear force, it was found that a second-order vortex-excited resonance existed. The cross-wind response in the test was smaller than Eurocode estimation. The aerodynamic damping ratio was calculated by random decrement technique and the results showed that aerodynamic damping ratios were mostly positive at the design wind speed, which means that the wind-induced galloping phenomenon is predicted not to occur at design wind speeds.

Multi-scale Modeling for the Stress Analysis of Acrylic Joints in a Hybrid Structure

Yanfeng Zheng,Yaozhi Luo,Xian Xu,Chao Yang,Zhongyi Zhu,Yuekun Heng 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.4

The central detector at the Jiangmen Underground Neutrino Observatory (JUNO) is a hybrid structure system consisting of an inner acrylic sphere and an outer stainless steel reticulated shell. The stress distributions of the acrylic joints must be accurately simulated to avoid “crazing”. To balance the accuracy and effi ciency of the stress analysis, a multi-scale modeling method using mixed-dimensional coupling is proposed. A framework and a generalized procedure are developed to instruct the modeling and analysis. A multi-scale model consisting of a single refi ned acrylic joint and equipped with simplifi ed joints is proposed and discussed. A comparison of the results using the multi-scale model with a cluster of 3 × 3 refi ned joints reveals that the diff erence is less than 5%, while the ratio of the computation resource cost and the time consumption is approximately only 1/7 and 1/5, respectively. The stress distributions of the acrylic joints in the central detector are obtained using the proposed multi-scale model.

Implementation of SHM system for Hangzhou East Railway Station using a wireless sensor network

Yanbin Shen,Wenwei Fu,Yaozhi Luo,Chung Bang Yun,Dun Liu,Pengcheng Yang,Guang Yang,Guangen Zhou 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.1

Structural health monitoring (SHM) is facilitated by new technologies that involve wireless sensor networks (WSNs). The main benefits of WSNs are that they are distributed, are inexpensive to install, and manage data effectively via remote control. In this paper, a wireless SHM system for the steel structure of Hangzhou East Railway Station in China is developed, since the state of the structural life cycle is highly complicated and the accompanying internal force redistribution is not known. The monitoring system uses multitype sensors, which include stress, acceleration, wind load, and temperature sensors, as the measurement components for the structural features, construction procedure, and on-site environment. The sensor nodes communicate with each other via a flexible tree-type network. The system that consists of 323 sensors is designed for the structure, and the data acquisition process will continue throughout its whole life cycle. First, a full-scale application of SHM using a WSN is described in details. Then, it focuses on engineering practice and data analysis. The current customized WSN has been demonstrated to have satisfactory durability and strong robustness; hence, it well satisfies the requirements for multi-type sensors to operate in a large area. The data analysis results demonstrate that the effects of the construction process and the environment on the super-large-scale structure have been captured accurately. Those effects include the stress variation throughout the construction process, the dynamic responses that are caused by passing trains, the strain variation caused by temperature change over the long term, and the delay in the wind-pressure history.