Effect of Infill Parameters on the Compressive Strength of 3D-Printed Nylon-Based Material

Abstract

3D printing is the most suitable method to manufacture the frame parts of powered ankle-foot prostheses but the compressive strength of the 3D-printed part needs to be ensured. According to the compression test standard ASTM D695, the effect of infill pattern and density, which is transferred to the mass of the standard specimen, on the compressive strength is investigated with a carbon fiber-reinforced nylon material. With the same infill pattern, specimens with more mass have a higher compressive strength. With the same mass, specimens with triangular fill have a higher compressive strength than those with rectangular and gyroid fills. Compared with specimens with a solid fill, specimens with a triangular fill can also provide more compressive strength in a unit mass. According to the results of standard specimens, following the requirement of strength and lightweight, 41% triangular fill is selected to manufacture the supporting part of a powered ankle-foot prosthesis. Under a compressive load of 1225 N, the strain of the assembly of the standard adaptor and the 3D-printed part is 1.32 ± 0.04%, which can meet the requirement of the design. This study can provide evidence for other 3D-printed applications with the requirement of compressive strength.

Compressive Strength of 3D Fabricated Parts: Experimental and Numerical Studies

“…Hernandez et al confirmed these findings [6]. Liu et al [7] study the compressive strength of a carbon fiber-reinforced nylon material by varying the infill parameters. The conclusion is that parts with triangle infill have the highest compressive strength.…”

Glass Fibre-Reinforced Extrusion 3D-Printed Composites: Experimental and Numerical Study of Mechanical Properties

“…One of the most used fibre-reinforced composite filaments in functional 3D printing is the chopped glass or carbon fibre-reinforced nylon filaments due to their mechanical, chemical, and thermal properties [ 14 ]. Research on the effect of the infill of such materials can already be found [ 15 , 16 , 17 , 18 ], mainly due to the fact that the orientation of fibres inside the nylon should contribute to its mechanical properties significantly, and the most investigated mechanical properties are the tensile and compressive strengths of the samples, which is quite strange considering the fact that fibre reinforcement is commonly used to enhance materials’ flexural strength. However, these studies are quite limited in their scope and do not investigate other important parameters, and the choice of other parameters is hardly stated, and often when they are stated, they seem to be chosen randomly or are the factory presets, which should be modified based on a number of factors.…”

Effect of nozzle diameter and raster orientation on tensile and fracture behavior of FDM‐PLA specimens under mixed‐mode I/II loading

“…According to the study performed by Ramesh and Panneerselvam, 14 the fill parameters such as fill pattern and infill density were introduced as the main effective factors in improving the ultimate tensile strength. However, Liu et al 15 showed that the triangle fill pattern with high infill density provides a better performance from a compressive strength point of view. Hsueh et al 16 reported that the mechanical performance especially the tension, bending, and compression properties of the FDM products increased as the printing temperature increased.…”