Efecto en las propiedades mecánicas del tamaño de impresión de estructuras tipo lattice de PA-12 fabricada mediante SLS

Abstract

Topology optimization method for weight reduction of additive manufacturing parts is commonly achieved throughout the creation of lattice structures, typically generated with beams of small size cross-section. In this paper, a methodology for determining the mechanical properties of small size pillars printed in PA-12 material, using Selective Laser Sintering (SLS) method is presented. The effect of manufacturing defects on these macroscopic properties is studied and the mechanisms that determine these properties in the printed material are analyzed. A methodology for the determination of these properties is proposed, which includes the successive correction of the printed nominal diameters based on two approximations, one due to the outer skin of unmelted material and the other due to internal melting defects. Once the material properties have been determined, depending on the cross-section of the lattice pillars, the numerical simulation of latticetype structures has been carried out and the degree of adjustment of the proposed methodology has been experimentally verified, obtaining good results. This methodological validation provides a reliable method for the simulation of the macroscopic behavior of lattice-type structures with reduced sizes, taking into account the intrinsic defects generated during the printing process.