| 摘要: |
| 对建筑用PTFE(聚四氟乙烯)膜材进行单轴应力松弛和徐变试验，得到松弛模量和蠕变柔量随时间的变化曲线，然后采用广义线性黏弹性模型、分数阶模型和分指数模型分别进行数值模拟，再比较各模型预测精度.结果表明：各类模型模拟短期的松弛模量和蠕变柔量有较好的精度；随时间增长，广义线性黏弹性模型模拟的松弛模量和蠕变柔量偏离试验值，长期预测精度较差；分数阶模型对长期松弛模量和蠕变柔量预测精度较好；分指数模型可预测长期的经向蠕变柔量，但对长期松弛模量和纬向蠕变柔量的预测精度不高. |
| 关键词: PTFE膜材 应力松弛 徐变 黏弹性模型 材料试验 数值模拟 |
| DOI：10.3969/j.issn.1007 9629.2012.02.011 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(50778129,90815003) |
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| Study on Stress Relaxation and Creep Properties of PTFE Membrane |
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MENG Lei, WU Ming er
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Department of Building Engineering, Tongji University, Shanghai 200092, China
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| Abstract: |
| The relaxation modulus and creep compliance curves of PTFE membrane against time were obtained by the uni axial stress relaxation and creep tests. The generalized linear viscoelastic model, fractional model and fractional exponential model were adopted to simulate the test curves and make precision comparisons. The analysis results show that all the above models can be used to describe the relaxation modulus and creep compliance of PTFE membrane in the short time. For the generalized linear viscoelastic model, the relaxation modulus and creep compliance in the long time do not agree with the test results, this model has a low precision in the long term prediction. For the fractional model, the long term relaxation modulus and creep compliance can be predicted well. The fractional exponential model can predict the warp creep compliance in the long time, but it has a low precision for the long term prediction for the relaxation modulus and weft creep compliance. |
| Key words: PTFE membrane stress relaxation creep viscoelastic model material test numerical simulation |
