ETFE薄膜气枕模型试验研究

设计制作了2个不同矢跨比的ETFE薄膜气枕模型,进行了气枕形状测试、加压以及铺砂加压试验,得到了气枕形状坐标以及膜面随气压的变形量。对ETFE薄膜进行单向拉伸试验,测得材料的屈服强度、切线弹性模量和割线弹性模量。利用几何非线性有限元进行了数值分析,将数值结果与试验值进行了比较分析。结果表明:ETFE薄膜可按各向同性材料分析,数值计算结果与试验值吻合较好;在同样内压作用下,气枕矢高较高时膜面位移与膜面应力较小;ETFE薄膜采用割线弹性模量计算得到的膜面位移与试验值比较吻合,采用切线弹性模量计算得到的变形小于试验值。

Experimental study on ETFE foil cushion

Two experimental models with different ratios of rise to span are used in the experiments.After checking the upper layer shapes of the ETFE foil cushions,the loading tests are carried out by means of increasing the internal pressure with and without sands paved on the upper layer foil.The displacements of the upper layer foil are measured in the tests.The yield strength,the tangent and the secant Young′s modulus of ETFE foil used in the experimental models are obtained from the tensile test.Numerical analysis is performed by using nonlinear finite element method in which ETFE foil is considered as an isotropic material.Studies show that both the displacement and stress of the cushion model with large ratio of rise to span are smaller than those of the model with small ratio of rise to span.It is also found that the numerical results are much close to the results from the model tests when the secant Young′s modulus of ETFE foil is used in calculation.