Numerical analysis of mechanical behaviour of lattice and porous structures

摘要

Lattice and porous structures have attracted attention in scientific literature due to the development of 3D printers that facilitate their manufacturing. A thorough understanding of the mechanical behaviour of these structures is necessary. In this work, several lattice and porous structures are analysed using the finite element method. Eleven configurations have been studied using periodic boundary conditions, in order to numerically estimate their elastic mechanical properties (Young's modulus, shear modulus and Poisson's ratio) as a function of the structure porosity. In addition, a tensile fracture test has been modelled to analyse the predicted fracture pattern as well as the stress-strain curve for each structure. It is shown that structures based on spherical holes distributions lead to stiffer structures in tensile and shear conditions. The distribution of cavities has a strong influence on the mechanical behaviour. The square distribution improves stiffness, while the hexagonal distribution improves the shear modulus. Random distributions clearly decrease the stiffness and strength of the structure, although the damage in these structures is more progressive. Therefore, this work provides a comparative study to assess the influence of the lattice topological structure on some mechanical properties of interest in structural engineering, as a function of porosity.