Analysis and Test of the Inflatable Tubes of ETFE Foils

In order to reveal the vibration characteristics of the inflatable tubes of ETFE foils, the modal analysis was carried out for a 2.3m long inflatable tube of ETFE Foils. The equilibrium shape of the inflatable tubes was obtained from the static calculation with geometric nonlinearity. Modes of the inflatable tubes were achieved by the Lanczos method. The effect of boundary conditions, the inflatable pressure, the elastic modulus and air added mass on the vibration characteristics was analyzed. Analysis shows that the elastic modulus and air added mass have significant effect on the natural frequencies of the cantilever inflatable tubes. First frequency of the inflatable cantilever tube is less than the inflatable tube without constrains. Inner pressure has a slight effect on deformation modes with beam bending characteristics. The numerical method based on ABAQUS finite element analysis is reliable according to a comparison between test and simulation results.