ETFE薄膜材料参数设计值研究

By now, the design method of ETFE foil structures and the determination of design values of material property of ETFE foil have not been studied sufficiently. No official design specification related to ETFE foil structures can be found. Firstly, uniaxial tensile tests using five kinds of ETFE foils with different thickness (307 pieces of specimen in total) are carried out in this paper. The stress and strain of the first yield point, the second yield point and the tensile limit point at the tensile curve of ETFE foil are obtained and the elastic modulus are calculated. Secondly, the standard values of tensile strength of ETFE foil for both single-layer tension type and cushion type ETFE structures are suggested by considering the material property and the mechanical behaviors ETFE foil structures. Lastly, the strength uncertainty parameters and the geometry uncertainty parameters are determined. Utilizing the statistic data of component resistance uncertainty and load uncertainty, the partial safety factor for resistance and the design values of strength of tension type and cushion type structures are calculated in the case of wind load combination and snow load combination. The elastic modulus and Poisson's ratio of ETFE foil are also suggested in the paper.