Synergistic design of curved beam metastructure with tunable nonlinearity deformation and Poisson’s ratio

Abstract

Mechanical metastructures have gained extensive attention owing to their preeminent mechanical properties. However, how to effectively and conveniently design metastructures with tunable nonlinearity mechanical behaviors remains a fundamental yet unexplored challenge. In this study, two types of curved beam metastructure (CBM) are proposed, referred to as the single curved beam metastructure (SCBM) and double curved beam metastructure (DCBM). The Poisson’s ratio, load-bearing capacity, and energy absorption characteristics of CBM are explored through numerical simulations and experiments. The results show that SCBM and DCBM not only provide exceptional flexibility, exhibiting various nonlinearity characteristics such as negative stiffness, bi-stable, quasi-zero stiffness (QZS), and positive stiffness, but also possess the unique ability to switch the Poisson’s ratio sign. Additionally, multiple deformation modes can be tailored by introducing gradient design, allowing for controlled and orderly transformation between these modes. The outstanding nonlinearity characteristics of CBM make them ideal for designing multifunctional structures. This study offers a novel approach for the tunable design of nonlinearity deformation and Poisson’s ratio, promoting the application of tunable CBM in fields such as aerospace and automotive engineering.