Research On Wind Load And Wind-induced Response Of National Aquatics Centre Based On Health Monitoring

In order to welcome the 2008 Beijing Olympics, china has constructed a number of large-span structures.The National Aquatics Centre is one of them. As application of an innovative structural style, new materials and new technology, National Aquatics Centre has attracted worldwide attention.In recent years, along with the development of intelligence material, the structure healthy safety monitor technique got extensive concern. To embody the spirit of Hi-tech Olympics and at the same time to protect the health and safety of the structure, headquarters of the National Aquatics Centre was established research projects of the National Aquatics Centre steel membrane structural health monitoring system in 2006. Harbin Institute of Technology not only took the responsibility for design, installation, commissioning and operation of the monitoring system, but also conducted in-depth analysis of the data from monitoring system, so as to provide a scientific basis on security of structure and performance. This text used the data measured by the health monitoring system of the National Aquatics Centre, and developed the following research:The analysis of the characteristics of roof wind of the National Aquatics Centre.We have analysed the characteristics of the wind speed, wind direction, wind angle of attack,turbulence intensity,turbulence integral length,turbulent wind speed spectrum etc.We got the regulation of turbulence intensity, gust factor and turbulence integral scale for the change of wind speed.And we also compared the measured wind spectrum with the experienced wind spectrum and found that Von Karman spectrum and Panofsky spectrum is in good agreement with the measured horizontal and vertical turbulence wind velocity spectra, respectively.The analysis of the characteristics of roof wind load of the National Aquatics Centre.We analysed the wind pressure distribution of roof,power spectral characteristics of fluctuating wind pressure,and relevant characteristics of wind pressure of the National Aquatics Centre;And we come to the conclusion that: the wind load on the roof surface of the National Aquatics Centre was mainly wind pressure; Roof near the front with a larger wind suction, and with the increasing distance from the roof, wind loads gradually decreased; Pressure power spectrum in low frequency bands can be better in line with the power spectrum of wind flow field, but large differences in high frequency bands.The value of wind pressure spectrum is generally higher than that of wind speed spectrum in high frequency bands.Wind speed power spectrum instead of the wind load power spectrum suggested by criterion is more applicable in low-frequency phase, but not in high-frequency phase.The analysis of wind-induced dynamic response of the ETFE membrane structure of the National Aquatics Centre.We analysed the spectrum characteristics and modal parameters of ETFE membrane structure of the National Aquatics Centre,and then done some preliminary research on the fluid-structure coupling effect.From this study we found that the vibration of ETFE membrane structure is a broadband process, and the structure predominant period changed with the speed of wind.From the identification results, we can see,modal parameters of ETFE membrane also changed with the wind load.The damping ratio identified is very high,the maximum damping ratio as high as 30%, much higher than the general rigid structure damping ratio.