| 摘要: |
| 针对建筑用聚氯乙烯（PVC）涂层聚酯纤维膜材，采用单舌、双舌和梯形撕裂法进行单轴撕裂试验，分析了膜材的撕裂破坏机理和主要特点，比较了试验结果，考察了3种撕裂方法的适用性，发现梯形撕裂法撕裂机理较为单纯，更接近于实际结构中膜材撕裂的平面受力状态，且试验结果较为稳定，是值得推荐的撕裂性能测试方法；同时，采用双轴中心撕裂方法进行膜材的撕裂试验，即：在十字形试样中心预制长度为40mm、方向与膜材经向夹角分别为0°、45°和90°的I字形切缝，观察其在荷载比为1∶1的正交双向荷载作用下的裂缝扩展过程，并采用非接触式方法测定了膜面的应变场分布，结果表明：切缝角度会影响双轴中心撕裂的抗撕裂强度和裂缝扩展模式，双轴中心撕裂过程中，膜面最大应变几乎始终集中在裂缝尖端撕裂三角区内. |
| 关键词: 单轴撕裂试验 双轴中心撕裂方法 撕裂扩展 应变场 |
| DOI：10.3969/j.issn.1007 9629.2020.03.021 |
| 分类号: |
| 基金项目:国家自然科学基金面上项目(51778458) |
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| Experimental Study on Tearing Behavior of PVC Coated Polyester Fiber Membrane |
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BAO Han, ZHANG Xubo, WU Minger
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Department of Building Engineering, Tongji University, Shanghai 200092, China
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| Abstract: |
| The tearing performance of polyvinyl chloride(PVC) coated polyester fiber membrane commonly used in membrane structure was experimentally studied in detail. Uniaxial tearing tests including single tongue, double tongue and trapezoid shaped methods were carried out and the failure mechanism and main characteristics of them were analyzed. It is found that trapezoid tearing test is relatively simple and much closer to the plane loading condition of tearing of membrane in practical structure, its test result is relatively stable, so that it is worthy recommending tearing test method. The experimental results are compared and the applicability of the three methods is examined. The biaxial central tearing method was used to test the type I slit prefabricated in the center of the cruciform specimen. The initial slit length is 40mm and at an angle of 0°, 45° and 90° to the warp direction. The crack propagation process under 1∶1 orthogonal biaxial loading was observed and the strain field distribution on membrane surface was measured by non contact method, resulting in a conclusion that the tear strength and crack propagation mode are affected significantly by the slit angle and the maximum strain during the process always appears in the del zone of the crack tip. |
| Key words: uniaxial tearing test biaxial central tearing method tear propagation strain field |
