Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 55 4 2023 06 22 Developing a new functionally graded lattice structure based on an elliptic unit cell for additive manufacturing and investigation of its properties Developing a new functionally graded lattice structure based on an elliptic unit cell for additive manufacturing and investigation of its properties 475 494 5141 10.22060/mej.2023.21736.7504 FA Hedyeh MojaveryAgah Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran Masood Asgari Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran 0000-0002-2063-8699 Journal Article 2022 09 04 The use of additive manufacturing provides the opportunity to create complex geometries at a low cost. This paper introduces a novel nature-inspired additive manufactured graded lattice structure based on an elliptic unit cell. Altering the unit cells' dimensions by the dimension ratios in each repetition results in a graded layer. Linear tessellated layers provide a highly porous, graded structure whose specific properties can be customized at any spatial location. Geometric features were calculated with high accuracy using analytical analysis. Abaqus simulations were utilized to determine the mechanical properties of unit cells, layers, and lattices. A compression test was conducted on a polymer specimen made by digital light processing (DLP) to validate the results. For a conformal model, the elastic modulus along the latitude axis is five times bigger than the value along the longitude axis. An 8.8-fold increase in the elastic modulus is achievable by decreasing the longitude ratio from 1 to 0.75. A reduction of 0.3% in porosity by setting the longitude ratio to 0.75 and a decrease of 2% in porosity by lessening the latitude ratio to 0.75 results in increases of 2.6 and 2.77 folds in the elastic modulus along two directions, respectively. It is possible to tailor geometrical and mechanical properties to meet any design preference by selecting the proper dimension ratios, which can be utilized for medical implant design. The use of additive manufacturing provides the opportunity to create complex geometries at a low cost. This paper introduces a novel nature-inspired additive manufactured graded lattice structure based on an elliptic unit cell. Altering the unit cells' dimensions by the dimension ratios in each repetition results in a graded layer. Linear tessellated layers provide a highly porous, graded structure whose specific properties can be customized at any spatial location. Geometric features were calculated with high accuracy using analytical analysis. Abaqus simulations were utilized to determine the mechanical properties of unit cells, layers, and lattices. A compression test was conducted on a polymer specimen made by digital light processing (DLP) to validate the results. For a conformal model, the elastic modulus along the latitude axis is five times bigger than the value along the longitude axis. An 8.8-fold increase in the elastic modulus is achievable by decreasing the longitude ratio from 1 to 0.75. A reduction of 0.3% in porosity by setting the longitude ratio to 0.75 and a decrease of 2% in porosity by lessening the latitude ratio to 0.75 results in increases of 2.6 and 2.77 folds in the elastic modulus along two directions, respectively. It is possible to tailor geometrical and mechanical properties to meet any design preference by selecting the proper dimension ratios, which can be utilized for medical implant design. https://mej.aut.ac.ir/article_5141_130ea938864f051b9a40c85b6a713306.pdf