Evolution and parameter analysis of cable-membrane structure for the Expo Axis

Taking the design process of the Expo Axis cable-membrane structure as a subject,this paper discussed the mechanical evolution and scheme development.Various schemes were proposed along with the analysis of structural response using nonlinear finite element method.The comparison of stress and deformation analysis were made in the study from several angles such as without valley cable scheme,with valley cable scheme,gravity hammer scheme,and middle mast scheme.Parametric analysis was carried out including analyzing the relationship between structural performance and dead weight,elastic modulus,Poisson's ratio,flexible boundary,etc.The results show that structural alternative is the major factor that affects mechanical properties of the system,while material properties have the minimal impact on the overall performance.The structural weight should be taken into account at form-finding stage for long-span structure or heavier membrane.It is recommended that the flexible support system should be adopted to avoid the inconsistence of the calculation assumptions and the actual situation.