Investigation of bi-directional re-entrant anti-tetrachiral structure for regulating negative Poisson's ratio

Bi-directional re-entrant anti-tetrachiral (BRATC) structure with negative Poisson's ratio is developed in this paper to meet the requirement in the variation of morphing wing area. Inherited from the anti-tetrachiral (ATC) structure, the BRATC has the potential of lightweight and out-of-plane stiffness properties, which is suitable for simultaneous deformation and load-bearing capability in the design of morphing wings. At the same time, inspired by the design idea used in re-entrant anti-tetrachiral (RATC), the BRATC structure has improved the potential of deformability by relaxing the rotation constraints of the ligaments. The effect of the geometric parameters on the equivalent mechanical properties of BRATC, such as elastic modulus and Poisson's ratio was investigated by using the finite element method. The relation between geometric parameters and the mechanical properties is then obtained. Finally, mechanical properties of the BRATC structure are tested with the aid of additive manufacturing technology in the tensile experiment.

Automated summary

In this paper, a bi-directional re-entrant anti-tetrachiral (BRATC) structure with negative Poisson's ratio was developed to meet the requirement in the variation of morphing wing area. The BRATC structure inherits the lightweight and out-of-plane stiffness properties of the anti-tetrachiral (ATC) structure, making it suitable for simultaneous deformation and load-bearing capability in the design of morphing wings. By relaxing the rotation constraints of the ligaments, the BRATC structure has improved deformability potential. The mechanical properties of BRATC were investigated using the finite element method and tested in a tensile experiment with additive manufacturing technology.