A new calculation method of in-plane elastic properties analytical model for novel nested honeycomb with negative Poisson's ratio and enhanced Young's modulus

Inspired by the idea of springs connected in parallel, a new calculation method for the nested parallel cell of honeycomb with negative Poisson's ratio (NPR) and Young's modulus reinforcement is proposed, which states the in-plane Young's modulus of the parallel cells is equal to the sum of Young's modulus of the inner and outer sub-cells. Poisson's ratio is only related to the outer sub-cell. Four types of double parallel cells are designed and used to verify the method and deduce the analytical model, expressed using dimensionless parameters and verified by finite element (FE) simulation. Based on the results above, the calculation method is expanded to the triple parallel cells, and the correctness is verified. The elastic mechanical properties of quintuple parallel cells are forecasted. The method proposed in this paper provides an idea for designing and calculating Young's modulus of NPR nested honeycomb materials in subsequent research. •A new calculation method is stated to obtain the expression of Young's modulus of the nested cell, which states the in-plane Young's modulus of the nested cells is equal to the sum of Young's modulus of the inner and outer sub-cells, , i.e., enhancing Young's modulus.•The calculation method is extended to a triple parallel set and the forecast of mechanical properties of the purely sub-cells up to the quintuple parallel set.