Mechanics Properties of Negative Poisson's Ratio Honeycomb Structures with Variable Arc Angle Curved Concave Sides

A variable arc angle curved concave honeycomb structure with negative Poisson's ratio effect was proposed based on the circular honeycomb structure. The bending internal forces of the rigid frame structures were analyzed and the analytical formulas of the transverse/longitudinal equivalent elastic modulus and the equivalent Poisson's ratio were obtained by using the energy method. The proposed curved concave honeycomb structure might be degenerated into the existing circular honeycomb structure when the arc angle is as 180°. The present analytical solutions were in agreement with the existing theoretical solutions and finite element results, which showed the validity of the present method. Based on the obtained analytical solutions, the effects of the microstructure geometric parameters on the equivalent elastic modulus and the equivalent Poisson's ratio were discussed. The research results show that the equivalent elastic modulus is significantly affected by the arc angles. The equivalent Poisson's ratio is also obviously affected by the arc angles, the lengths of vertical walls and the widths between two vertical walls, while the influences of the connected part lengths are not obvious. © 2019, China Mechanical Engineering Magazine Office. All right reserved.