Design And Characterization Of Chiral Cell Assembly Honeycomb Structure For Complex Deformation Requirements

For the traditional chiral cellular honeycomb structure,most of the studies focus on the repetitive and periodic assembly of a single cell,and the deformation is single and lacks of design freedom to achieve more advanced functions,so it is difficult to achieve the required deformation.Appeared in recent years,combining mechanics metamaterials and algorithm of the method,has realized the reverse design of complex deformation non-uniform honeycomb structure,because of this combination is very new and immature,attracted the attention of many scholars,the paper proposed a method of a system,based on the chiral cell,can build on-demand deformation of chiral honeycomb structure.Firstly,the concept of chiral deformability is proposed to describe the degree of chiral deformability of chiral cell,and the optimal scheme is selected as the construction cell of non-uniform honeycomb structure according to the analysis of different types of chiral cell.The stiffness matrix of chiral cell is solved by canonical equation and energy method,and its deformation characteristics are analyzed.The influence of the relative parameters of the cell element on the chiral deformation degree and compression stiffness is analyzed by finite element method.The single control of the chiral deformation degree of the cell element parameters is realized and the numerical fitting is carried out.Secondly,a matrix coding method is proposed to characterize the chiral cell honeycomb structure.According to the simple deformation requirements,different types of chiral cell assembly honeycomb structure are designed,and the deformation of the honeycomb structure is understood through finite element analysis and experimental analysis.In view of the complex deformation requirements,the idea of reverse structure design using genetic algorithm is proposed,and the feasibility of this method is verified by some cases.Finally,based on the negative Poisson's ratio characteristic of the inverse quad chiral cell,the potential application of genetic algorithm to optimize the distribution of the inverse quad chiral cell to construct the on-demand deformation non-uniform honeycomb structure is discussed.The formulas of Poisson's ratio and equivalent elastic modulus are derived theoretically,and the accuracy of the theoretical derivation is verified by finite element analysis.The effects of various parameters on the negative Poisson's ratio and the equivalent elastic modulus of the structure are analyzed,and the minimum fitness function of genetic algorithm is constructed by using the corresponding relationship,and the relevant cases are provided.