Design and Analysis of 3d Printed Functionally Graded Lattice Structures

Abstract

Abstract Additive Manufacturing (AM) is a layer-by-layer fabrication method using 3D CAD designs. It has enabled the production of Lattice structures (arrangements of unit cells representing crystal lattices). Functionally Graded Lattice Structures (FGLS) with varying relative density for targeted properties are gaining research interest. This study explored mechanical properties such as strength, stress-strain relations, deformation behaviour, and energy absorption in lattice structures. CAD software Creo Parametric 9.0 was utilized to model five distinct 3D lattice designs employing novel approaches like different unit cells and pattern arrangements. Fifteen Lattice Structure Samples made of Nylon PA 2200 were fabricated through Selective Laser Sintering (SLS), and compression tests were conducted for experimental analysis. Numerical analysis was performed using ANSYS-19 software and results were compared with the experimental results. Distinct deformation behaviour was observed for FGLS compared to Uniform lattice structures (UB). Among all lattice structures, uniform and bidirectional graded lattice structures with strong middle layer exhibited the highest yield strength, while Variable Pattern FGLS displayed the lowest. Similarly, bidirectional graded lattice structure with weak middle layer showcased the best plateau region performance. Hybrid FGLS demonstrated the largest energy absorption, three times that of the variable pattern lattice structure. The results tabulated could be useful to guide future research and applications based on specific property requirements. This study showcases the potential of AM to create lattice structures with tailored mechanical properties, advancing their utilization in various industries.