A Study on the Mechanical Properties of 3D Printed PLA Specimens According to Infilled Pattern and Printing Direction

Abstract

This paper intended to measure the material's rigidity according to the orientation of the PLA specimen produced by the FDM method. To measure the change of strength and stiffness according to the direction of stacking of FDM PLA, the specimen was manufactured and tested not only in the direction of stacking but also infill using line pattern and concentric pattern. The intensity of each direction was 38.11MPa with a 0 degree tensile in the line pattern, 3.45 times higher than 11.9MPa with a 90 degree tensile, and 2.15 times higher shear strength with 28.05MPa and 13.88MPa. In concentric pattern, 0 degree tensile was 50.62MPa, 6.25 times higher than 8.46MPa, and 2.23 times higher in shear strength at 13.52MPa compared to 29.56MPa. The biggest difference in zero-degree concentric pattern tensile was the 37% difference in the 0 degree concentric pattern factor. This shows that the difference in intensity according to direction is more pronounced in concentric patterns than line patterns, and the behavior under load will be similar until the breaking point regardless of the direction.