Expected Ideal Solution and Verified By Numerical Analysis for a Triangular Unit Cell Model

This study aims to provide critical information regarding the development of ultralight materials with tailored properties using a triangular unit cell model. Three different types of triangular unit cells (or triangular prism unit cells, e.g. OST, OTT, and CTT) were studied via finite element analysis to calculate and compare their relative density, stiffness, and strength. The relative stiffness and strength were extracted under a compression load. The ideal solutions were calculated using commercial finite element analysis software and then compared to the ideal Gibson–Ashby solution. The relative Young’s modulus and the relative yield strength for the three different unit cell models are shown to differ from the ideal solution of the Gibson– Ashby theory. In conclusion, the effective stiffness of the OTT and CTT is higher than that of the Gibson-Ashby model. When the relative density is more than 0.1, the OTT and CTT have higher yield strength. OTT and CTT have a higher plastic strength when the relative density is more than 0.03–0.05. For aerospace or automobile use, further study is needed to find the optimum truss and aperture sizes and shape of the unit model. Keywords: Cellular solids; Effective medium; Relative properties; Triangular unit cell