A theoretical model of postbuckling in straight ribbons with engineered thickness distributions for three-dimensional assembly

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:147

Article

Zhang, Fan^1,2,3  Fan, Zhichao^1,2,3  Zhang, Yihui^1,2,3 

[1] Tsinghua Univ, Dept Engn Mech, AML, Beijing 100084, Peoples R China

[2] Tsinghua Univ, Ctr Flexible Elect Technol, Beijing 100084, Peoples R China

[3] Tsinghua Univ, Ctr Mech & Mat, Beijing 100084, Peoples R China

关键词: 3D assembly;    Modeling;    Origami;    Finite deformation;    Optical shutter;   

DOI  :  10.1016/j.ijsolstr.2018.05.030

来源: Elsevier

【 摘 要 】

Mechanically-guided three-dimensional (3D) assembly of mesostructures through controlled compressive buckling represents a promising approach, because of the versatile applicability to a broad set of advanced materials, over length scales from sub-micrometers to centimeters. Based on this approach, a spatial variation of thickness in the initial 2D structures was demonstrated as an effective strategy to produce engineered folding deformations at regions with lower bending stiffness, thereby with an ability to enable autonomous origami assembly. The reliability of this strategy requires the development of a theoretical model as a design reference, such that targeted folding deformations can be achieved without inducing any structural failure. This work presents a finite-deformation model of controlled buckling in straight ribbons with engineered thickness reductions at two or three sites. A comparison of predicted maximum strains and deformed configurations to the finite element analyses (FEA) and experimental results elucidates the validity of the developed model. The results uncover the coupled effect of different geometric parameters on the maximum strain. For relative flexible creases that lead to evident folding deformations, the theoretical model gives approximate analytic solutions to the deformed configurations and maximum strain. Furthermore, the theoretical model was exploited in a design optimization to achieve highly sensitive rotatable micro-mirrors with a desired mechanical tunability of the optical transmittance. This study can be useful in the future designs of 2D precursor structures for the origami-inspired assembly of different 3D mesostructures and micro-devices. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

Free