PTFE膜材的单向拉伸性能.pdf

第13卷第4期
建筑材料学报
Vol. 13, No 4
2010年8月
JOURNAL OF BUILDING MATERIALS
Aug.,2010
文章编号:1007-9629(2010)04-0535-05
PTFE膜材的单向拉伸性能
张营营,张其林,周传志
(同济大学建筑工程系,上海200092
摘要:介绍了PTFE膜材的单轴拉仲试验方法,对该膜材在0°,15°,30°,45,60°,75°,90°这7个偏
轴方向的拉伸试验特征进行了分析,并讨论了其拉伸断裂破坏机理及适用的相关强度准则,最后
进行了应变速率分别为10%6,25%,50%,100%,200%,500%min'的单向拉仲试验,得到了相应
的断裂强度、断裂延仲率的变化规律.结果表明:PTFE膜材是典型的正交各向异性材料;利用
Tsai-Hill强度准则能够对PTFE膜材的抗拉强度做出較好的预测;PTFE膜材的抗拉强度随着应
变速率的増加略有增加,而断裂延伸率则略有减少,且与应变速率的对数呈较好的线性关系
关键词:PTFE膜材;カ学性能;各向异性;强度准则;应变速率
中图分类号:TB332;TU502
文献标志码:Adoi:10.3969/j.issn.1007-9629.2010.04.024
Uniaxial Tensile Properties of PTFE Membrane Material
ZHANG Ying-ying, ZHANG Qi-lin, ZHOU Chuan-zhi
Department of Building Engineering, Tongji University, Shanghai 200092, China)
Abstract: Uniaxial tensile testing methods of PTFE membrane materials were introduced in this paper.
Tensile performances of the specimens were analyzed in seven in-plane directions including 0, 15, 30, 45
60%, and 90. The rupture mechanisms of the materials and the corresponding strength criterion were
discussed. Uniaxial tensile tests were carried under six kinds of tensile speeds(tensile strain speeds: 10%
25%, 50%6,100%,200%,500% min ), and the breaking tensile strength and tensile strain under differen
tensile speeds were also obtained. Results indicate that PTFE membrane material is typically orthotropic
and Tsai-hill strength criterion can be used for predicting the failure strength of PTFE coated fabrics.
With the increase of the tensile speed, the tensile strength of PTFE membrane increases slightly while the
breaking tensile strain decreases, which show the good linear relationship with the logarithm of strain
speeds.
Key words: poly tetra fluoro ethylene(PTFE) membrane material; mechanical property; anisotropy;
strength criterion; tensile strain speed
PTFE膜材是在超细玻璃纤维织物上涂覆聚四清洁面层与透光性.但这种膜材价格较高、纤维较脆
氟乙烯(PTFE)树脂加工而成.PTFE膜材厚度一般抗折性能差,运输及施工过程中的卷折会使其强度降
大于0.5mm,面密度为420~1600g/m2,强度、弹性低,且混、热环境对其力学性能有一定的影响,因此需
模量大,力学性能稳定,耐高温、严寒、腐蚀性能较好,要在设计、裁剪过程中进行精确计算、妥善加工处理
不会因为紫外线和放射线的影响而老化或催化,适用
膜材种类繁多,其性能受外部环境影响很大,且
于永久性建筑;具有良好的自洁性和憎水性,大气中结构的破坏模式复杂,尚未建立统一的强度准则,这
的灰尘极难附着与渗透,经雨水清洗便可恢复原有的是目前膜结构设计大多采用安全系数法的原因.但
收稿日期:2009-11-24;修订日期:2009-12-30
基金项:国家自然科学基金资助项目(90815003);上海市科学技术委员会世博科技专项(08dz0580305
第一作者:张营营(1985-),男,山东潍坊人,同济大学博士生.Email:zhangyingying850163.com