Investigation of spatial variability on strut diameters of additively manufactured lattice structures

Abstract

In this study, the influence of the spatial variability ofgeometric uncertainties on the strut members of the latticestructures fabricated by additive manufacturing is investigated.Individual struts are fabricated with various printing angles anddiameters using a material extrusion process and PLA material.The diameter values of the fabricated samples are measuredalong the printing and radial directions at each layer under anoptical microscope. Spatial correlations are characterized basedon the measurements using the experimental autocorrelationfunction. Candidate autocorrelation functions are fitted to themeasured data to identify the best fitted one for each diameterparameter and the corresponding correlation lengths areevaluated for random field. The applicability of the KarhunenLoève expansion (KLE) is investigated to reduce thedimensionality of the random field discretization. The resultsshow that the diameters of the strut members at each layer arespatially dependent and the KLE method was found to give agood representation of the random field. © 2020 American Society of Mechanical Engineers (ASME). All rights reserved.