Defining relationships between geometry and behavior of bistable composite laminates
Defining relationships between geometry and behavior of bistable composite laminates
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定义双稳态复合材料层压板的几何形状和行为之间的关系
DOI：
10.1177/00219983211005824
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发表时间：
2021
影响因子：
2.9
通讯作者：
Fadel, George
中科院分区：
文献类型：
--
作者：
Phatak, Salil;Myers, Oliver J;Li, Suyi;Fadel, George
当物体可以处于两个稳定的平衡状态时，就会表现出双稳态。某些复合层压板通过具有相反符号的两个稳定曲率且两个曲率轴彼此垂直而表现出双稳态。这些层压板可以从一种状态驱动到另一种状态。从原始后固化形状到第二形状的驱动称为“快速通过”，反向驱动称为“快速返回”。这种现象可用于变形结构、能量收集和其他对承载、轻型和形状适应性结构有冲突要求的应用。 MW Hyer 在 1981 年的论文中首次报道了这一现象。他发现薄的不对称层压板的行为并不符合经典层压理论 (CLT) 的预测。 CLT 是一种线性理论，预测薄的不对称层压板的固化后形状为鞍形。 MW Hyer 开发了一种称为“扩展经典层压理论”的非线性方法，该方法准确预测层压板具有两种圆柱形形状。从那时起，许多研究人员试图确定影响此类层压板行为的关键参数。诸如堆叠顺序、纤维取向、固化周期、边界条件和驱动力等几何参数都已被研究。本研究的目的是定义实现双稳态所需的方形和矩形层压板的长度、宽度和厚度之间的关系。利用这些关系，可以制造出厚度为 30 层 CFRP 的 36 英寸×36 英寸双稳态层压板。此外，还证明，只要矩形层压板的两侧都高于某个“临界长度”，层压板就不会随着纵横比的增加而失去双稳定性。制造了尺寸为 2 英寸× 50 英寸的双稳态层压板。此外，对于双稳态层压板，必须能够预测驱动所需的曲率和力。因此，开发了一种方法，使我们能够预测两种稳定形状的曲率，以及已知厚度和尺寸的层压板的驱动力。有限元分析用于进行数值计算，并通过制造层压板进行验证。使用轮廓仪测量这些层压板的曲率，并使用通用测试装置记录驱动力。
Bistability is exhibited by an object when it can be resting in two stable equilibrium states. Certain composite laminates exhibit bistability by having two stable curvatures of opposite sign with the two axes of curvature perpendicular to each other. These laminates can be actuated from one state to the other. The actuation from the original post-cure shape to the second shape is called as ‘snap-through’ and the reverse actuation is called as ‘snap-back’. This phenomenon can be used in applications for morphing structures, energy harvesting, and other applications where there is a conflicting requirement of a structure that is load-carrying, light, and shape-adaptable. MW Hyer first reported this phenomenon in his paper in 1981. He found that thin unsymmetric laminates do not behave according to the predictions of the Classical Lamination Theory (CLT). The CLT is a linear theory and predicts the post-cure shape of thin unsymmetric laminates to be a saddle. MW Hyer developed a non-linear method called the “Extended Classical Lamination Theory” which accurately predicted the laminate to have two cylindrical shapes. Since then, a number of researchers have tried to identify the key parameters affecting the behavior of such laminates. Geometric parameters such as stacking sequence, fibre orientation, cure cycle, boundary conditions, and force of actuation, have all been studied. The objective of this research is to define a relation between the length, width and thickness of square and rectangular laminates required to achieve bistability. Using these relations, a 36 in × 36 in bistable laminate is fabricated with a thickness of 30 CFRP layers. Also, it is proved that a laminate does not lose bistability with an increase in aspect ratio, as long as both sides of the rectangular laminate are above a certain ‘critical length’. A bistable laminate with dimensions of 2 in × 50 in is fabricated. Further, for laminates that are bistable, it is necessary to be able to predict the curvature and force required for actuation. Therefore, a method is developed which allows us to predict the curvature of both stable shapes, as well as the force of actuation of laminates for which the thickness and dimensions are known. Finite Element Analysis is used to carry out the numerical calculations, which are validated by fabricating laminates. The curvature of these laminates is measured using a profilometer and the force of actuation is recorded using a universal test set-up.
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影响因子：
4
作者：
Betts, D. N.;Kim, H. A.;Inman, D. J.
通讯作者：
Inman, D. J.
影响因子：
2.8
作者：
Betts, D. N.;Bowen, C. R.;Inman, D. J.
通讯作者：
Inman, D. J.
DOI：
10.1016/j.compositesa.2011.03.012
发表时间：
2011-07-01
影响因子：
8.7
作者：
Tawfik, Samer A.;Dancila, D. Stefan;Armanios, Erian
通讯作者：
Armanios, Erian
DOI：
10.1016/j.compositesa.2009.05.018
发表时间：
2009-08
影响因子：
8.7
作者：
J. Etches;K. Potter;P. Weaver;I. Bond
通讯作者：
J. Etches;K. Potter;P. Weaver;I. Bond
用于能量收集的双稳态压电复合材料板的静态和动态分析
影响因子：
9.1
作者：
D. Betts;H. A. Kim;C. Bowen;D. Inman
通讯作者：
D. Inman