メカニカルメタマテリアルにおける引張応力誘起収縮現象とノーマルモード

抄録

Mechanical meta-materials are the materials or structures which do not exist in nature but are artificially created to generate abnormal mechanical properties. Here we numerically studied the mechanical properties and found a novel phenomenon; when the material is pulled under linearly increasing stress, the material undergoes collapse transition at a given critical stress, and the stress-strain curve exhibits “S” shape. In order to understand the dynamical behavior of the system, we applied the normal mode analysis to the mechanical metamaterials by using numerical diagonalization. As a result, we found that there exists one floppy (zero frequency) mode as well as conventional acoustic modes at smaller frequencies and optical modes at large frequencies.