A Study on Optimum Filler Shape of Negative Thermal Expansion Material in Thermal-Expansion-Adjustable Composites

Abstract

In mechanic engineering, it is important to suppress the influence of thermal expansion for machinery. In order to control thermal expansion, thermal-expansion-adjustable composites with negative thermal expansion materials are expected to be used. However, the optimum filler shape of negative thermal expansion material is not clear. In this paper, we present the optimum filler shapes derived from two methods: Eshelby’s inclusion model and topology optimization. Eshelby’s inclusion model is an accurate method to predict the properties of composites from the properties of constituent materials. Since this method can take the filler shape into account as aspect ratios of fillers, the optimum filler aspect ratio can be determined. Topology optimization can be used for more detailed analysis. The analysis was performed many times by giving a random initial shape and running the optimization calculation.