Abstract
Exploring performance by structural design and assembly strategies, mechanical metamaterials have recently attracted attention due to their prominent mechanical properties compared with traditional structures. Structural instability (e.g., buckling) has been deployed to form architected structures for multifunctional applications. Here, we report novel types of hierarchical metastructures composed of postbuckled elements, which have programmable mechanical characteristics under tension and compression. Simply tuning the geometries of the postbuckling elements, the presented metastructures have promising mechanical response (i.e., programmable tensile and compressive stiffnesses, zero Poisson’s ratio, and recovery from large deformation). The reported hierarchical metastructures were fabricated and assembled using a 3D printing technique. Experiments were conducted and the results were validated with the analytical and numerical models with satisfactory agreement. The programmability is investigated with respect to the geometries of the bi-constrained beams. In favor of the buckling-induced, elastic deformation of the bilaterally constrained elements, the reported metastructures can be deployed for multipurpose applications, such as energy dissipation through the repeatable deformation-recovery process or damage detection based on the variation of postbuckling mode configuration.
Highlights
Expanding for programmable mechanical performance, architected structures have recently been formed by periodic substructures to exhibit extraordinary features,1–3 which otherwise cannot be observed, e.g., effective stiffness resistance,4,5 negative Poisson’s ratio,6 configuration recovery,7,8 or ductility under large deformation.9,10 Other than the material perspective that has been explored from homogeneous to inhomogeneous, the effect of the engineered pattern on structures has been investigated in recent years.11–13 Significant research interest has been dedicated to breaking the rule to obtain otherwise unachievable mechanical properties, e.g., having conflicting properties at the same time14–16 or decoupling interactive properties.17,18 In particular, the architected mechanical metamaterials are designed to harness their mechanical response, e.g., programmability, one-way propagation, or shape morphing, for advanced functional applications
The existing studies are typically valid for one-direction loading: (2) we develop the theoretical and numerical models to investigate the mechanism of the metastructures, and the metastructures can be effectively designed with accurately controllable mechanical response; and (3) the potential applications in energy dissipation and damage detection are based on the mechanical response of the metastructures, and the applications can be achieved by only designing the geometric properties
We developed the hierarchical metastructures with programmable mechanical characteristics and well recoverability scitation.org/journal/apm using periodically patterned elasticas subjected to bilateral constraints
Summary
Expanding for programmable mechanical performance, architected structures have recently been formed by periodic substructures to exhibit extraordinary features, which otherwise cannot be observed, e.g., effective stiffness resistance, negative Poisson’s ratio, configuration recovery, or ductility under large deformation. Other than the material perspective that has been explored from homogeneous to inhomogeneous, the effect of the engineered pattern on structures (i.e., from the structural perspective) has been investigated in recent years. Significant research interest has been dedicated to breaking the rule to obtain otherwise unachievable mechanical properties, e.g., having conflicting properties at the same time or decoupling interactive properties. In particular, the architected mechanical metamaterials are designed to harness their mechanical response, e.g., programmability, one-way propagation, or shape morphing, for advanced functional applications. Theoretical and numerical models are developed to validate the postbuckling-induced mechanical response, which are further used to reveal the influences of the geometry and periodic pattern on the programmable stiffness and recoverability. Comparing with the existing studies, the uniqueness of the chosen design in this study can be concluded as (1) we take advantage of the structural instability (i.e., postbuckling response) to obtain tunable mechanical characteristics under both tension and compression. The existing studies are typically valid for one-direction loading: (2) we develop the theoretical and numerical models to investigate the mechanism of the metastructures, and the metastructures can be effectively designed with accurately controllable mechanical response; and (3) the potential applications in energy dissipation and damage detection are based on the mechanical response of the metastructures, and the applications can be achieved by only designing the geometric properties. The metastructure-enabled applications are electricity-independent, which significantly increases their sustainability in reality
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call