建筑膜材料撕裂强度的测试方法及撕破机理研究

Study on Tear Testing Method and Rupture Mechanism of Architectural Membrane Materials

比较了目前国外用于测试膜材料撕裂强度的主要方法和标准,分析了不同测试方法对膜材料撕裂强力的影响,讨论了膜材料的撕裂机理。试验研究表明双舌撕裂法很难稳定控制裂缝撕裂方向,从而导致无效试样较多,不适合用于膜材料撕裂性能测试。中心裂缝撕裂法的测试结果受试样裂缝尺寸的影响较大,在提出新的测试指标之前,暂不宜将其测出的断裂强力直接作为膜材料的特征参数。梯形撕裂法的撕裂模式单纯,试验结果也较稳定,是值得推荐的膜材料撕裂强度测试方法。

Some tear testing methods and standards used for architectural membrane materials by overseas manufacturer are compared. The influences of testing conditions on tear strength of samples are analyzed. The rupture mechanism of architectural membrane materials are also discussed. It is discovered that the double tongue tear test is not applicable for testing tear strength of architectural membrane materials because the testing method is difficult to maintain stable tear direction, resulting in more invalid tests. It is also found that the initial crack length has great influences on testing values of samples for the mono-axial centre slit tear test, so the testing value cannot be used directly to describe tear property before new testing indexes are presented. Different from above mentioned two methods, the rupture mode of the trapezoidal tear test is simple and the testing results are stable. Thus, this method is recommended for testing tear strength of architectural membrane materials.