Paper-cut metamaterial with adjustable auxetic characteristic under large stretching amount and design method of paper-cut metamaterial

Abstract

The invention relates to a paper-cut metamaterial with an adjustable auxetic characteristic under a large stretching amount and a design method thereof, the paper-cut metamaterial is composed of a plurality of square unit cells which are arranged in order, and the plurality of unit cells are arranged in the paper-cut metamaterial in a periodic, gradient or irregular mode. Corresponding paper-cut metamaterials respectively have a uniform auxetic characteristic, a gradient auxetic characteristic and a specified non-uniform auxetic characteristic. The design method comprises the steps that firstly, a structure optimization method is adopted, out-of-plane deformation constraint is fully considered, and heuristic design of a unit cell configuration is obtained; secondly, geometric reconstruction and parameter modeling are carried out on an optimization result obtained in the above steps, and the tension and expansion characteristics under different geometric parameters are obtained; and finally, the plurality of unit cell configurations are arranged according to a specific arrangement sequence, and the paper-cut metamaterial is constructed. According to the invention, by modifying the parameters of the shear mouth, a plurality of tension and expansion characteristic change trends which can be adjusted along with the tension amount can be realized; compared with the existing paper-cut metamaterial, the metamaterial provided by the invention has obvious advantages in structural design, application range and application prospect.

Description

technical field [0001] The invention belongs to the field of metamaterials, and relates to a kirigami metamaterial with adjustable auxetic properties under a large stretching amount and a structure design method thereof. Background technique [0002] Kirigami metamaterials are a type of mechanical metamaterials that obtain specific equivalent mechanical properties through the orderly (periodic, gradient, irregular) arrangement of notches on the thin sheet structure. Advantages such as waste and fast load response. [0003] The auxetic kirigami metamaterial produces transverse expansion deformation under the action of longitudinal tensile load, and this auxetic property can be expressed as the negative value of the ratio of the average transverse deformation to the longitudinal elongation. At present, the existing auxetic kirigami metamaterials are designed based on artificial experience or by trial and error, and the arrangement of notches included has mirror-image symmetry...

AI Technical Summary

Problems solved by technology

[0004] When the above-mentioned auxetic kirigami metamaterials elongate beyond a certain percentage of the sample size (usually less than 10%), unstable out-of-plane buckling deformation occurs, resulting in failure to maintain the specified auxetic properties

On the one hand, this is due to the small out-of-plane stiffness of the sheet structure, and on the other hand, due to the fact that the preset notch and the notch layout reduce the out-of-plane stiffness of the local area

At the same time, the existing auxetic kirigami metamaterials are prone to high strain (or high stress) under large stretching, leading to the failure or even destruction of the matrix material, which affects the reliability, deformation recoverability and equivalent performance of the metamaterial. cause negative impact

The performance deficiencies in these two aspects limit the practical application of kirigami metamaterials

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