【摘要】 通过对PVC膜材料进行7种应力比下的双轴拉伸试验(比值分别为0∶1、1∶5、1∶2、1∶1、2∶1、5∶1和1∶0),对膜材料在双轴拉伸作用下的拉伸特性进行了研究。在试验过程中施加了3次循环荷载,以使得经过循环作用后的膜材料的性能更接近实际使用的情况。结果表明膜材料具有明显的正交异性和非线性。该文推导了双轴拉伸作用下经纬向应变之间的关系,结合试验所得的变形特性,就经纬向应力比C≤0.5时,经向弹性常数为负这一现象作了分析。根据已有的理论,对膜材料双轴向弹性常数进行了分析,当C=1时,膜材料的经向和纬向同时具有最大的弹性常数。更多还原

【Abstract】 Through biaxial tensile tests of architectural membrane materials at seven warp to weft stress ratios , which are 0∶1, 1∶5, 1∶2, 1∶1, 2∶1, 5∶1 and 1∶0 respectively, tensile performances of the samples under biaxial tensile loads are analyzed. The cyclic load pattern with three cycles is applied for the purpose that after cyclic loads, the experimental properties of membrane materials will agree well with actual properties of membrane materials applied in structures. The test results show that the behavior of membrane materials is highly nonlinear and anisotropic under biaxial tensile loads. A model is developed to build relationships between warp strains and weft strains. Combined with the deformation characteristics obtained from the test, the phenomenon that the elastic constant in the warp direction is negative while C≤ 0.5 is studied. With the analysis of biaxial elastic constants of membrane materials, it is obtained that at the condition of C=1, there are the biggest elastic constants in the both warp and weft directions.更多还原