On the Behavior of Honeycomb, Grid and Triangular PLA Structures under Symmetric and Asymmetric Bending

Additive manufacturing technologies enable the production of components with lightweight cores, by means of infills with various patterns and densities. Together with reduced mass and material consumption, infill geometries must ensure that strength and stiffness conditions are fulfilled. For the proper correlation of the infill type with the loading case of the part, the mechanical behavior of the infill along all three principal axes of inertia has to be known. In this paper, the behavior in symmetric and asymmetric bending of three infill geometries, commonly used in 3D printing processes (honeycomb, grid and triangles) is analyzed. The variations of deflections as a function of force orientation are presented, showing that honeycomb and triangular structures exhibit similar behaviors along the Y and Z principal axes of inertia. Furthermore, the displacements obtained for the three types of structures are compared, in relation to the consumed volume of material. The larger displacements of the grid structure compared to the honeycomb and triangular structures are highlighted.

Automated summary

Additive manufacturing technologies allow the production of lightweight components with various patterns and densities of infills. Infill geometries must satisfy strength and stiffness requirements while reducing mass and material consumption. This study analyzes the behavior of three commonly used infill geometries (honeycomb, grid, and triangles) in symmetric and asymmetric bending. The results show similar behaviors for honeycomb and triangular structures along the Y and Z principal axes of inertia, and highlight the larger displacements of the grid structure compared to the other two structures in relation to the consumed volume of material.