Analysis of 3D printed material properties through biaxial test

Additive manufacturing, commonly known as 3D printing, has gained prominence in various industries such as medical, aerospace, and automotive due to its capacity to create intricate geometries using cost-effective materials. The widespread availability of 3D printers has necessitated a closer examination of the mechanical properties of 3D printed components for engineering applications. Previous studies have investigated the mechanical properties of 3D printed polymers, considering factors like filament color, raster orientation, layer thickness, moisture, and other process parameters. While standard material tests have been employed in these studies, this paper focuses on biaxial testing, a non-standard material test, to gain additional insights into material behavior under two-directional loading. Biaxial testing subjects 3D printed polyactic acid (PLA) samples to in-plane biaxial stress and strain, providing a comprehensive understanding of their mechanical behavior. This paper presents the experimental methodology, including the cruciform sample geometry, manufacturing processes, and biaxial testing parameters. A total of 28 specimens underwent various biaxial loading conditions, and strain measurements were recorded using a unique method involving circular artifacts. Results and discussions highlight the differences in strain measurements under various loading conditions, revealing distinct patterns in how 3D printed PLA responds to biaxial stress. The forming limit diagrams generated from this study provide valuable insights into the material properties of PLA subjected to biaxial tension and compression. Limitations and opportunities for future research are also discussed, suggesting avenues for improving the precision of 3D printed specimens and expanding the scope of investigations. In conclusion, this research contributes essential baseline data on the mechanical behavior of 3D printed PLA under biaxial stress, offering valuable insights for engineering applications and paving the way for further advancements in additive manufacturing.