Design of three dimensional isotropic microstructures for maximized stiffness and conductivity

TL;DR

This paper uses the level-set method to design three-dimensional isotropic microstructures that maximize both stiffness and conductivity, demonstrating new composite designs with superior mechanical properties.

Contribution

It introduces novel isotropic microstructures with enhanced stiffness and conductivity, expanding the design capabilities of multifunctional composites using topology optimization.

Findings

Schwartz primitive and diamond surfaces yield maximal bulk modulus and conductivity.

New isotropic composites are at least 23% stiffer than traditional structures.

Level-set method effectively designs microstructures with tailored isotropic properties.

Abstract

The level-set method of topology optimization is used to design isotropic two-phase periodic multifunctional composites in three dimensions. One phase is stiff and insulating whereas the other is conductive and mechanically compliant. The optimization objective is to maximize a linear combination of the effective bulk modulus and conductivity of the composite. Composites with the Schwartz primitive and diamond minimal surfaces as the phase interface have been shown to have maximal bulk modulus and conductivity. Since these composites are not elastically isotropic their stiffness under uniaxial loading varies with the direction of the load. An isotropic composite is presented with similar conductivity which is at least 23% stiffer under uniaxial loading than the Schwartz structures when loaded uniaxially along their weakest direction. Other new near-optimal isotropic composites are presented, proving the capablities of the level-set method for microstructure design.