Mechanical deformations of a liquid crystal elastomer at director angles between 0° and 90°: Deducing an empirical model encompassing anisotropic nonlinearity
Mechanical deformations of a liquid crystal elastomer at director angles between 0° and 90°: Deducing an empirical model encompassing anisotropic nonlinearity
复制标题
DOI：
10.1002/polb.24879
复制
发表时间：
2019-10
期刊：
影响因子：
--
通讯作者：
D. Mistry;H. Gleeson
中科院分区：
文献类型：
--
作者：
D. Mistry;H. Gleeson
尽管大量的研究报道了液晶弹性体(LCE)的力学性能，但目前还没有理论能够描述其完全的力学各向异性和非线性。在这里，我们通过同时跟踪液晶(LC)指向矢旋转的拉伸测试，对全丙烯酸酯液晶电致发光器件的力学各向异性进行了fi第一次全面研究。然后，我们使用经验方法对初始指向矢取向介于0(CID：1)和90(CID：1)之间的应变值为1.5时的LCE的S力学响应进行了更深入的了解。利用类似于时间-温度叠加的方法，我们建立了液晶盒S力学响应的主曲线，并利用这些曲线推导出一个模型，该模型能够准确地预测液晶盒在与初始LC指向矢成15(CID：1)到70(CID：1)夹角的应力作用下的载荷曲线。这个LCE在垂直于指向矢的变形中表现出伸展行为。有趣的是，我们的经验模型预测，当LCE与导演成54(Cid：1)到90(Cid：1)之间的夹角时，LCE将进一步表现出伸展行为。我们的方法可以扩展到任何大规模并行计算，因此它代表着向有助于大规模并行理论和基于大规模并行计算技术的设计和建模的进一步发展的模型迈进了一大步。©2019作者。聚合物科学期刊，B部分：聚合物物理，由威利期刊公司出版。科学，B部分：多晶硅。太棒了。2019、57、1367
: Despite the wealth of studies reporting mechanical properties of liquid crystal elastomers (LCEs), no theory can currently describe their complete mechanical anisotropy and nonlinearity. Here, we present the fi rst comprehensive study of mechanical anisotropy in an all-acrylate LCE via tensile tests that simultaneously track liquid crystal (LC) director rotation. We then use an empirical approach to gain a deeper insight into the LCE ’ s mechanical responses at values of strain, up to 1.5, for initial director orientations between 0 (cid:1) and 90 (cid:1) . Using a method analogous to time – temperature superposition, we create master curves for the LCE ’ s mechanical response and use these to deduce a model that accurately predicts the load curve of the LCE for stresses applied at angles between 15 (cid:1) and 70 (cid:1) relative to the initial LC director. This LCE has been shown to exhibit auxetic behavior for deformations perpendicular to the director. Interestingly, our empirical model predicts that the LCE will further demonstrate auxetic behavior when stressed at angles between 54 (cid:1) and 90 (cid:1) to the director. Our approach could be extended to any LCE; so it represents a signi fi cant step forward toward models that would aid the further development of LCE theory and the design and modeling of LCE-based technologies. © 2019 The Authors. Journal of Polymer Science Part B: Polymer Physics published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57 , 1367