Preparation method of negative thermal expansion metamaterial sandwich panel based on topological optimization design

Abstract

The invention discloses a preparation method of a negative thermal expansion metamaterial sandwich panel based on topological optimization design. The preparation method comprises the following steps: (1) establishing an overall structure model of the negative thermal expansion metamaterial sandwich panel; (2) establishing a metamaterial-based structure finite element model for filling the sandwich panel; (3) inputting basic material parameters, constraint values and a finite element model of the metamaterial-based structure; (4) calculating values of an equivalent thermal expansion coefficient and an equivalent elastic modulus of the metamaterial and corresponding partial derivatives; (5) establishing an explicit optimization model, and solving through linear programming; (6) judging whether the equivalent thermal expansion coefficient convergence precision is met or not, and if the equivalent thermal expansion coefficient convergence precision is not met, returning to the fourth step; and if the equivalent thermal expansion coefficient convergence precision is met, inverting the optimal continuous topological variable until the equivalent elastic modulus requirement is met, to obtain an optimal topological structure; and (7) modeling the filled metamaterial, and filling the negative thermal expansion metamaterial in a periodic array between clamping plates to form the negative thermal expansion sandwich plate. The method has more design freedom degrees and better performance.

Description

Technical field [0001] The present invention relates to a layout design of a sandwich plate filler structure, which is suitable for structural concept design considered to consider thermal expansion compensation. Background technique [0002] Topological optimization is the most challenging research field in structural optimization design, is an innovative design method. Continuous body structure optimization is designed to look for the best material distribution in the design area, and achieve target performance. Topology optimization is designed for each unit in the finite element division structure, compared to dimensional optimization and shape optimization with more design freedom, it is possible to break through the design of experience in the design, so it is favored by the majority of designers. [0003] Head expansion is common in engineering applications, and it is easy to produce large deformation when temperatures, affecting the accuracy of structural operation. Local...

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Problems solved by technology

[0003] Thermal expansion is a common phenomenon in engineering applications. When the temperature is high, it is easy to produce large deformation, which affects the accuracy of structural work.

Accumulated local deformation can easily lead to stress concentration, especially when working in extreme environments, and the thermal load is often a cyclic load, so the risk is relatively high

In some projects, the precision requirements are very high, so how to eliminate the influence of thermal expansion is very important; current aerospace mostly uses synthetic materials to compensate thermal deformation, but the cost is high and the adjustable range is relatively small

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