ETFE薄膜单向拉伸性能

对3种厚度的ETFE(乙烯-四氟乙烯共聚物)薄膜沿MD及TD方向裁取的试样进行了单向拉伸试验,得到了相应的应力-应变拉伸曲线、抗拉强度及断裂延伸率.通过分析,给出了确定拉伸曲线上2个刚性转折点的方法,由此得到了对应于转折点的屈服应力和应变;给出了ETFE薄膜弹性模量的计算方法,并由拉伸曲线计算得到了切线弹性模量、割线弹性模量、第二和第三弹性模量;借助高精度数字照相方法,测定了ETFE薄膜的泊松比.结果表明,试验中采用的ETFE薄膜材料沿MD及TD方向的单向拉伸特性基本相同.

Uniaxial Tensile Properties of ETFE Foils

Uniaxial tensile tests of ethylene tetra fluoro ethylene(ETFE) foils are described in this paper.Three kinds of ETFE foils with different thicknesses are used in the tests and the specimens are cut from foils along the machine direction(MD) and the transverse direction(TD).The tensile strength,the tensile strain at break and the stress-strain curve are obtained from the tests.A method to determine the two different turning points of the stress-strain curve is given.According to the curve of stress and strain,the yield stress,the yield strain and the elastic modulus are calculated.By means of high resolution digital photography,the Poisson ratio of ETFE foil is measured.From the test results,it is found that the tensile properties of the foils along the machine direction and the transverse direction are almost the same,which means that the ETFE foils used in the tests can be taken as a type of isotropic material.