Reconfigurable Multi-stable Metastructures

Yong Zhang (PhD candidate), Marcel Tichem (supervisor), and Fred van Keulen (supervisor)

The design of mechanical meta-structures that exhibit unconventional properties has been a rapid field recently. One perspective of the meta-structure design to form flexible metastructures with reconfigurable and shape-changing abilities for energy and motion-driven applications. Different design approaches/principles have been adopted, which includes beam-based structures, origami-type elements and reinforced systems. In this project, we are mainly focusing on the beam-based elements, whose deformations are normally related to nonlinear-buckling behavior. Furthermore, this nonlinear behavior may bring another interesting properties, that is bi- or multi-stability. Creating mechanical metamaterials by assembling these nonlinear and multi-stable building blocks leads to a range of completely new functionalities.

Objectives

In this project, we are exploring the buckling-based multi-stable metastructures to bring in new functionalities, and extend these metastructures to own additional mechanical properties.

Methods

Rational design approaches are normally adopted for the design of such metastructures. Finite element simulations, experimental verification and analytical investigations are needed for the characterization of metastructures’ behavior.

Results

In this work, multi-stable meta-structures exhibiting both level and tilted stable states were designed on the basis of snapping beams. In particular, the 3D unit element shown in the figure is able to realize four stable states, including two level and two tilted stable configurations. By arranging the proposed units in different manners, we can achieve a series of multi-stable metastructures with different tilting directions, depending on their in-plane symmetry. (e.g. the hexagonal metastructures shown in the figure possesses six tilted configurations).

Multi-stable structures with level and titled stable states

 

In addition, we also explored rotational behavior of the normal beam-type multi-stable metastructures on the basis of experimental, and numerical studies. The design condition which needs to be met for realizing rotational configurations is proposed, based on an analytical investigation.

 

Publications 

Peer-reviewed articles related to this work:

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