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The creation of functional materials is a promising direction for engineering development. Functional materials include metamaterials among others. Metamaterials achieve the required properties using a rationally designed structure. Tetrachiral structures differ from the others in that they can twist under uniaxial loading. This paper solves the quasi-static problem of uniaxial loading within the framework of linear elasticity theory using the finite element method. It is investigated how the support reaction changes when a second ring is added into the chiral structure. The dependence obtained suggests that by adding a complementary ring and increasing its size more forces have to be applied to deform the metamaterial. It is shown how the size of the secondary ring affects Young's modulus. [ABSTRACT FROM AUTHOR]

The paper deals with the problem of deforming a mechanical metamaterial. The metamaterial is constructed from chiral elements comprising rings and ribs. The behavior of the bulk metamaterial sample during compression was studied numerically in the framework of linear elasticity theory. Due to the chiral structure, the metamaterial sample exhibits unusual effects. One of them relates to nonlinear transformations, namely a twist. It was found that the deformations are distributed irregularly over the material. During the compression of the metamaterial sample, the rings undergo a torque, and the ribs begin to bend. All the ribs of the metamaterial sample undergo similar bending. Additionally, there are areas affected by two codirectional bends with different signs. Strain localization and the corresponding stress concentrations are of great importance from the strength analysis point of view. As for Young's modulus, it is significantly (by 100 times) less for the metamaterial sample than for the base material. It is justifiable since the ratio of the volume of a base solid to the volume of the metamaterial is quite large. When constructed the tetrachiral structure, the porosity value is 98%. [ABSTRACT FROM AUTHOR]