Structural Response Prediction of Thin-Walled Additively Manufactured Parts Considering Orthotropy, Thickness Dependency and Scatter

first_pagesettings Open AccessArticle Structural Response Prediction of Thin-Walled Additively Manufactured Parts Considering Orthotropy, Thickness Dependency and Scatter by Sigfrid-Laurin Sindinger 1,2,*OrcID,David Marschall 3,Christoph Kralovec 1OrcID andMartin Schagerl 1,2OrcID 1 Institute of Structural Lightweight Design, Johannes Kepler University Linz, 4040 Linz, Austria 2 Christian Doppler Laboratory for Structural Strength Control of Lightweight Constructions, 4040 Linz, Austria 3 KTM E-TECHNOLOGIES GmbH, 5081 Anif, Austria * Author to whom correspondence should be addressed. Academic Editors: Maria Magdalena Pastor and Jordi Bonada Materials 2021, 14(9), 2463; https://doi.org/10.3390/ma14092463 Received: 18 April 2021 / Revised: 30 April 2021 / Accepted: 5 May 2021 / Published: 10 May 2021 (This article belongs to the Special Issue Experimental Testing and Numerical Simulation of Polymer-Based Additive Manufacturing Parts) Download PDF Browse Figures Citation Export Abstract Besides the design freedom offered by additive manufacturing, another asset lies within its potential to accelerate product development processes by rapid fabrication of functional prototypes. The premise to fully exploit this benefit for lightweight design is the accurate structural response prediction prior to part production. However, the peculiar material behavior, characterized by anisotropy, thickness dependency and scatter, still constitutes a major challenge. Hence, a modeling approach for finite element analysis that accounts for this inhomogeneous behavior is developed by example of laser-sintered short-fiber-reinforced polyamide 12. Orthotropic and thickness-dependent Young’s moduli and Poisson’s ratios were determined via quasi-static tensile tests. Thereof, material models were generated and implemented in a property mapping routine for finite element models. Additionally, a framework for stochastic finite element analysis was set up for the consideration of scatter in material properties. For validation, thin-walled parts on sub-component level were fabricated and tested in quasi-static three-point bending experiments. Elastic parameters showed considerable anisotropy, thickness dependency and scatter. A comparison of the predicted forces with experimentally evaluated reaction forces disclosed substantially improved accuracy when utilizing the novel inhomogeneous approach instead of conventional homogeneous approaches. Furthermore, the variability observed in the structural response of loaded parts could be reproduced by the stochastic simulations.