Pantographic metamaterials show atypical Poynting effect reversal
Pantographic metamaterials show atypical Poynting effect reversal
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DOI：
10.1016/j.mechrescom.2018.02.003
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发表时间：
2018-04-01
影响因子：
2.4
通讯作者：
Dell'Isola, Francesco
中科院分区：
文献类型：
--
作者：
Misra, Anil;Lekszycki, Tomasz;Dell'Isola, Francesco
在1909年提出的一项分析中，Poynting(文献[1]的第546页)表明，对于有限的弹性变形，最大伸缩的直线倾向于正方形被剪切成的菱形的对角线。这一发现的含义是，当细长的结构被扭曲时，它们经历了伸长，正如Poynting用导线[1]进行的测量实验所证实的那样。虽然许多理论分析表明存在Poynting效应和逆(逆)Poynting效应的可能性[2-7]，但对这种效应的测量相当稀少[8-11]。我们介绍了一种高度非线性的Pointing效应的测量，包括它在扭转过程中从正方向到负方向(拉伸到压缩)的反转。这种非典型的行为表现在一种相当特殊的材料系统上，它具有缩放式的内部结构。对于这种材料系统，经典的柯西型连续介质模型失效，需要一个二阶梯度连续介质模型来描述它的许多变形行为。(C)2018爱思唯尔有限公司。保留所有权利。
In an analysis presented in 1909, Poynting (page 546 of [1]) had shown that for finite elastic deformations, the lines of greatest extension and contraction are inclined to the diagonals of the rhombus into which a square is sheared. The implication of this finding was that when slender structures are twisted, they undergo elongation as experimentally verified by Poynting's measurements with wires [1]. While many theoretical analyses have shown the possibility of Poynting and reverse (inverse) Poynting effect [2-7], measurements of such effects are rather sparse [8-11]. We present here measurements of a highly nonlinear Poynting effect, including its reversal from positive to negative (elongation to compression) direction during torsion. Such atypical behavior is exhibited by a rather exceptional material system that has a pantographic internal structure. For this material system, the classical Cauchy-type continuum model fails and a 2nd gradient continuum model is necessary to describe many of its deformation behaviors. (C) 2018 Elsevier Ltd. All rights reserved.