Research On Structural Behavior And Key Problems Of ETFE Cushions

Beijing Olympic National Swimming Center is one of the primary gymnasiums of 2008 Beijing Olympic Games. In this project a new type of structure cladding system-ETFE cushion is adopted. Since the total cladding area of ETFE is up to twenty thousands square meters. It will be the biggest application project of ETFE. In this paper, the structural behavior and some key problems of ETFE cushions are analyzed.Firstly the history of membrane structure is reviewed. Then the characteristics and applications of ETFE are summarized. After the methods of form-finding and load analysis are introduced, an applied method of form-finding using ANSYS program is given.Secondly a cushion in roof of National Swimming Center is taken as an example in this paper. The general bearing property of EFTE cushions is introduced. Then the form finding analysis and static analysis of the structure subject to different loading is carried out. The design process of such ETFE structure is also presented.Inflation pressure and membrane stress level are important to ETFE cushions. The influence of temperature variation, rise and the thickness of ETFE membrane are investigated in this paper. Moreover, the effect of snow accumulation and laying cable net on ETFE cushions are considered.The design of connector is discussed and effect of membrane stress on the connector is calculated.At the end of the thesis some conclusions are summarized and the problems that should be studied further are put forward.