Switching of the deformation patterns of a periodic structural system and its loading rate dependence

Abstract

Lately, a variety of artificial mechanical metamaterials with multi-functionality, which appears under large deformations, have been designed and developed by incorporating specific geometric features into them. In our previous study, we proposed a class of repetitive structural systems under uniaxial compressive load, which exhibits the nonlinear elastic deformation response by switching two types of kinematic transformations. To resolve the deformation transition mechanism, we modeled a specific bar-and-joint framework with two angular variables specifying the rotation and distortion of the linked square components, and we showed that the switching behavior can be represented by a hyperbolic type of equilibrium paths of the system. In this study, we propose the extended model by replacing the spring elements with dashpot ones and discuss the singular switching characteristic depending on a loading rate.