Linear thermoelastic characterization of anisotropic poly(ethylene terephthalate) films
Linear thermoelastic characterization of anisotropic poly(ethylene terephthalate) films
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DOI：
10.1002/app.11179
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发表时间：
2002-12-13
影响因子：
3
通讯作者：
Farris, RJ
中科院分区：
文献类型：
--
作者：
Feng, R;Farris, RJ
所有九个独立的弹性常数已被确定为双轴拉伸聚（对苯二甲酸乙二醇酯）（PET）膜使用新的机械方法。正交各向异性的方向和面内泊松比的第一个特点是使用振动全息干涉拉伸膜样品。通过测量恒定应变条件下张力随压力变化的变化来获得面外泊松比。采用压力-体积-温度（PVT）装置测量了材料的体积压缩系数和体积热膨胀系数（TEC）。面内杨氏模量通过拉伸试验获得，而面外模量通过描述面内行为的可压缩性和其他弹性常数计算。使用热机械分析仪（TMA）确定机器方向和横向方向上的面内TEC。使用这些值和通过PVT确定的体积TEC确定的平面外TEC。由此产生的顺应性矩阵满足正定能量标准的所有要求。本文所采用的表征方法可适用于任何正交各向异性薄膜。(C)2002 Wiley Periodicals，Inc.
All nine independent elastic constants have been determined for a biaxially stretched poly(ethylene terephthalate) (PET) film using novel mechanical methods. The orthotropic directions and the in-plane Poisson's ratios were first characterized using vibrational holographic interferometry of tensioned membrane samples. The out-of-plane Poisson's ratio was obtained by measuring the change in tension with the change in pressure for constant strain conditions. Pressure-volume-temperature (PVT) equipment was used to measure the bulk compressibility as well as the volumetric thermal expansion coefficient (TEC). The inplane Young's moduli were obtained by tensile tests, while the out-of-plane, modulus was calculated from the compressibility and other elastic constants that describe the inplane behavior. The in-plane TECs in the machine and transverse directions were determined using a thermal mechanical analyzer (TMA). The out-of-plane TEC was determined using these values and the volumetric TEC determined via PVT. The resulting compliance matrix satisfies all of the requirements of a positive-definite energy criterion. The procedure of characterization utilized in this article can be applied to any orthotropic film. (C) 2002 Wiley Periodicals, Inc.