Heterogeneous hierarchical structure topological optimization method containing variable-size unit cells

Abstract

The invention belongs to the technical field of structural topological optimization, and particularly relates to a heterogeneous hierarchical structure topological optimization method containing variable-size unit cells. The method comprises the following steps: 1) defining a topological optimized microscopic design domain, and dividing a microscopic grid, a macro design domain and the like in thedomain; 2) establishing a design domain model; 3) selecting a size variable interpolation point; 4) fitting a function relationship between the dimension variable interpolation point and the equivalent elastic tensor thereof; 5) calculating a unit stiffness matrix and a macroscopic displacement field according to the size variable interpolation point; 6) calculating the interpolation point sensitivity of the flexibility function of the structure to the macroscopic design variable, the micro-unit cell size variable and the size variable, and completing the collaborative optimization design; According to the method, macro-micro collaborative optimization is achieved through the structure with the variable unit cell size, the problems that in the prior art, the unit cell length-width ratio is constant, and the performance potential of a microstructure is limited can be well solved, and spatial transformation of material attributes can be achieved by adjusting the distribution of the length-width ratio in space.

Description

technical field [0001] The invention belongs to the technical field of structural topology optimization, and in particular relates to a topology optimization method for a heterogeneous hierarchical structure with variable-size unit cells. Background technique [0002] Additive manufacturing, commonly known as 3D printing technology, is a special manufacturing process that accumulates layers of materials. It subverts the traditional manufacturing concept of subtractive materials and equal materials, gets rid of the constraints of traditional molds and tooling, and provides a powerful tool for the preparation of complex structures. Tool of. Hierarchical structures have structural configurations at multiple scales such as macro, sub, and micro. They have the advantages of high specific stiffness, multi-function, and adjustable space material properties. They are applied to aeronautical structures, biomedicine, and other fields. Therefore, it is of great significance to develop...

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Problems solved by technology

However, since the periodic hierarchical structure contains only one microstructure configuration on the macro scale, the design space is small and the structural performance improvement is limited.

[0005] In summary, the above-mentioned prior art discloses a microstructure design based on square unit cells, does not optimize the aspect ratio of the unit cell, and does not exert the performance potential of the microstructure. Therefore, it is necessary to study a new Hierarchical structure topology optimization design method to further improve the performance of 3D printing products by optimizing the microstructure

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