Compressive Strength Assessment of 3D Printing Infill Patterns

With the increasing popularity of 3D printed products, material consumption becomes a concern in additive manufacturing in recent years. Various lightweight structures (e.g., infill patterns) have been designed and used to reduce material use while supporting product functionality. Product designers and engineers often experience difficulties in choosing the infill structure when solid material is not necessary in an application, thus losing the potential of material and cost saving opportunities. This is due to a lack of comprehensive study on mechanical properties and sustainability performances of these infill patterns. The objective of this study is to understand the mechanical behaviors, economic and environmental benefits through compression test, life cycle cost assessment, and life cycle assessment. Fourteen common infill patterns including Grid, Lines, Triangle, Cubic, Tetrahedral, Concentric, Concentric 3D, Zigzag, Gyroid, Octet, Cross, Cross 3D, Tri-hexagonal and Quarter Cubic have been examined. The samples were printed with ASTM D695 standard cylinders made of Polylactic Acid using fused deposition modeling. Compression tests were conducted on an Instron test platform and the data was collected to compare the load and weight relations of all structures. The research results will provide a comprehensive mechanical inventory for product design and manufacturing. In addition, this study identifies opportunities for more robust infill pattern design for additive manufacturing.