Effect of Material Distribution in the Unit Cell on Effective Thermal Conductivity and Young's Modulus of Cellular Structure

Abstract

Effective thermal conductivity and Young's modulus of periodic unit cell geometries are widely studied in the literature. This paper compares and contrasts strut-based unit cells against surface-based unit cells obtained by subtracting spheres from a solid cube. In order to understand the reason for the difference in the behavior of effective thermal conductivity of surface-based and strut-based unit cell geometries and the difference in the behavior of Young's modulus of surface-based and strut-based unit cell geometries, the effect of material distribution on effective thermal conductivity and Young's modulus is studied here. The material in the unit cell is varied in two ways, i.e., by changing the material distribution on the cell wall (partially closed unit cell) and changing the material distribution across the strut of unit cell geometry. It is found that the distribution of material on the wall of the unit cell improves the effective thermal conductivity and Young's modulus. In contrast, a narrow cross-section area in the unit cell reduces the effective thermal conductivity and Young's modulus. Using the studied effect of material distribution on effective thermal conductivity and Young's modulus, the reason for the difference in properties of surface-based and strut-based unit cell geometry is qualitatively explained. Partially closed unit cell geometries introduced here for studying the effect of material distribution on cell walls give a wide range of effective thermal conductivity and Young's modulus for the same porosity with a change in pore opening ratio.