Tunable energy trapping through contact-induced snap-through buckling in strips with programmable imperfections

The concept of energy trapping has been recently demonstrated in modular architected materials at various length scales but most energy-trapping mechanisms retain its deformed shape and requires external loads to recover their initial states. Here, we demonstrated an on-demand, repeatable energy-trapping mechanism that enabled by interaction of buckled slender elements. Guided by experiments and numerical simulations, we proved that using a pre-defined imperfection on thin strips can generate a predictable and controllable element interaction, resulting trapped energy stored in the elements and a rapid energy release in a form of snap-through buckling. The amount of trapped energy can be tailored by changing imperfection design, imperfection amplitude, spacing between element and assembly of multiple components. The robustness of this mechanism is demonstrated by such a purely geometric design and thus can be applied over a range of scales and using different materials. We envision that the proposed mechanism can be integrated into buckling-induced smart devices such as energy harvesters and dampers. (C) 2020 Elsevier Ltd. All rights reserved.