Topological optimization method suitable for metamaterial with function gradient and stretching properties

Abstract

The invention belongs to the field of metamaterial design relevant technology and discloses a topological optimization method suitable for a metamaterial with a function gradient and stretching properties. The method comprises the steps that (1) a weighting method is adopted to establish a multi-objective optimization model of each layer considering microstructure stretching properties and macrostructure rigidity properties at the same time; (2) the stretching properties and the rigidity properties of the whole structure of the metamaterial in one direction are controlled to be distributed in a gradient form; (3) microscopic displacement and macroscopic displacement in a design domain on each layer and equivalent elasticity properties of a microstructure on each layer are calculated; and (4) an optimization criterion method is adopted to update design variables based on sensitivity obtained through calculation, and then whether an objective function is converged is judged. According to the topological optimization method, the weighting method is adopted to establish the multi-objective optimization model considering the microstructure stretching properties and the macrostructure rigidity properties at the same time, and then optimization is performed, so that the optimized metamaterial has the stretching properties and enough rigidity at the same time.

Description

technical field [0001] The invention belongs to the related technical field of metamaterial design, and more specifically relates to a topology optimization method applicable to metamaterials with functional gradient and auxetic properties. Background technique [0002] Metamaterials refer to composite materials that have artificially designed microstructures and exhibit extraordinary physical properties that natural materials do not have or have less. Auxetic material is a new type of mechanical metamaterial with negative Poisson’s ratio. It has unconventional mechanical properties such as vertical expansion under tension (vertical contraction under compression), so as to enhance the shear modulus, absorption Capability, crack resistance and fracture toughness, with functional characteristics that positive Poisson's ratio materials do not have. [0003] Engineering products based on auxetic metamaterials should be multifunctional, such as the protective structure of ships ...

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Problems solved by technology

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a topology optimization method suitable for metamaterials with functional gradient and auxetic properties, which simultaneously considers the spatial changes of the microstructure configuration and different performance indicators The combination of macroscopic loads and boundary conditions on the microstructure and other key factors solves the problem that the design method based on simulation, experiment or experiment cannot be realized or the cost is too high, so that the metamaterial material after topology optimization The structure has both auxetic properties and sufficient stiffness

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