Influence of anisotropy and walls thickness on the mechanical behavior of 3D printed onyx parts

Predicting the behavior and mechanical properties of 3D-printed parts is crucial for 3D printer users. This study conducted experimental investigations on Onyx 3D-printed parts to identify the most important printing parameters. These parameters were specimen positioning and the number of specimen walls. The experimental results indicated that specimens oriented in the XZ direction were 48% stiffer than those oriented in the XY direction and 54% stiffer than those oriented in the ZX direction. Additionally, the results demonstrated that walls significantly influenced the mechanical properties of specimens in the XY and XZ orientations but had no effect on those in the ZX orientation. The Young's modulus increased by 60% between a specimen with one wall and another with eight walls. This paper presents an analytical model for predicting mechanical properties based on the number of walls, with a prediction error ranging from 1% to 15%. Additionally, a numerical simulation approach was proposed to predict the mechanical behavior of parts. The numerical and experimental results comparison showed a 1% to 9% prediction error and a good correlation between numerical and experimental curves. These findings can be a valuable aid to engineers in the design of 3D printed mechanical concepts.