Multi-objective topology optimization for materials with negative Poisson’s ratio and thermal insulation

Thermal protection system (TPS) of spacecraft requires enhanced impact resistance and thermal insulation capability while pursuing higher stiffness. Considering this, a topology optimization method of periodic microstructures with negative Poisson’s ratio and insulation performance is proposed for the filling material design of the core layer in TPS, in which homogenization approach is adopted in calculating properties of microstructures and multi-objective optimization is used for balancing the mechanical and thermal properties of the optimized microstructures. Considering the optimization design of impact-resistant structures with negative Poisson’s ratio, a novel objective function is proposed to reduce the influence of iteration steps on the optimization results. For the topology optimization of insulation structures, a suitable objective function is selected by comparing the optimization results of two existing objectives. Based on the weighted linear combination, a multi-objective microstructural topology optimization method is proposed, simultaneously incorporating negative Poisson’s ratio and insulation performance. By adjusting the weighting coefficient of the objective functions, the microstructure of the materials can be designed according to different performance requirements. Several 2D and 3D optimized microstructures with both better impact resistance and insulation performance of TPS are successfully designed. In addition, the 2D optimized microstructures under different weights are assembled into sandwich structures, and the compression and heat conduction are simulated to further illustrates the validity and flexibility of the proposed method considering requirements of both impact-resistant and thermal insulation performances of sandwich structures.