設計可能な引張剛性を有するメタマテリアルの開発

抄録

The purposes of this study are to design and develop a mechanical metamaterial that exhibits two-stage stiffness and to formulate the stiffness. In a metamaterial we designed, a unit cell consists of two types of zigzag-shaped springs which are sandwiched between top and base parts. The upper ends of the springs are connected to the top part. The lower end of one spring is fixed to the base part. The lower end of the other, which has an inverted T-shape, floats in a hook fixed to the base part. Tensile tests were conducted to a metamaterial specimen consisting of 3×6 unit cells, which was fabricated by means of a 3D printer. The specimen showed significantly different stiffness in the earlier and later stages of the tensile deformation. By approximating the elements constructing the unit cell to plural beam elements, the stiffness of the metamaterial specimen was successfully formulated.