The influence of infill direction on the low cycle fatigue performance of 3D printed PLA polymer.

Abstract

Purpose of the thesis is to find out the infill direction on the low cycle fatigue performance of 3D printed PLA polymer. ISO 527 1B selects as a standard to prepare the sample, which was designed by SolidWorks software. Moreover, the Ultimaker S3 3D printer is being used to print the samples, which uses fused deposition modeling (FDM) technology. To operate the printing process, it selects 2.85mm diameter printing filaments and 0.4mm diameter two nozzle tips, where one of them was used for printing the samples and another one for printing support structures. There were also four different orientations, printed as PLA samples, gradually 0°,30°,45°, and 90° with the infill density was 20% for all of them. Tough PLA polymer was selected as the primary printing material to complete the printing procedure, which is the most popular plastic filament material in the 3D printing sector. Ultimaker Cura was used to convert the CAD file. Investigation of fatigue life in different infill orientations (0°,30°,45°, and 90°) also include in the thesis to find out the performance of fatigue life. The tensile Cycling method was used to identify the fatigue life of PLA polymer. Based on the test result, the 90° sample tolerated 6933 cycles which were its maximum point, where force was 750 N and speed was 150mm/min constant, which makes it the strongest compared to others. Apart from the others, the 45° sample is considered as the second strongest infill direction, and 30° is the weakest sample ever with 2390 cycles, and finally, 0° infill direction printed tough PLA sample tolerated 2707 at 750 N force makes it second weakest infill orientation. There for, it may consider that 90° is the best infill direction to print PLA polymer products by 3D printer.