Topology optimization of anisotropic multi-material structures considering negative Poisson's ratio and high thermal conductivity based on IGA approach

A multi-objective topological optimization model is proposed for anisotropic multi-material microstructures with negative Poisson's ratio (NPR) and high thermal conductivity using isogeometric analysis (IGA) approach and alternating active phases algorithm. The effective elasticity matrix and heat conductivity matrix are calculated to represent the metamaterial and thermal conduction properties of the microstructures, respectively. The weighting factor is defined to adjust the proportion of NPR and heat transfer performance in the optimization objective. The validity of the proposed model is confirmed by structural performance analysis. Additionally, the IGA-based optimal topological structures, which have continuous boundary and low intermediate density without sensitivity filtering, have been produced using 3D printing. The effects of weighting factor, the number of material types, and anisotropic parameters on the optimal topological structures and properties are investigated. Either increasing the weighting factor or upgrading to more materials with superior properties can boost the thermal conductivity of the microstructure. Compared to isotropic multi-material microstructures, it is recommended that the range for Poisson's ratio factor, heat conductivity factor be 1-1.5 and 1.25-1.5 to enhance the performance of microstructures, respectively.