Numerical investigation of the effective mechanical properties of Octet Truss lattice structures with different strut geometry

Abstract

Lattice structures have an important role in lightweight structure applications as they can supply their mechanical performance with less material. Porous structures designed with inspiration from nature, has been used in many industries such as aerospace, automotive, defense industry and biomedical field. In order to continue these advances, studies on various design configurations of porous structure geometries are carried out. This study aimed to increase the usage potential of Octet Truss lattice structures in various sectors. A numerical model is created for 3 variable parameters: strut geometry, porosity, and material type. The effective elastic modulus values are determined based on the principles of Hooke's law for each model. Based on the obtained effective elastic modulus values, it has been concluded that differences in strut geometries, porosities, and material types contribute to 1.27%, 68.85%, and 29.86% of the observed effects, respectively. In order to establish a correlation between these factors, the data is transmitted to the MATLAB software, where equations are generated using the curve fitting approach. A total of nine equations have been generated and the R-square for these equations above 0.99. According to the two desired constant values, the effective elastic modulus can be calculated using these equations without any restrictions.