Design and Comparative Numerical Analysis of AlSi10Mg LPBF-manufactured TPMS Lattice Structures for Mechanical Performance
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Additive manufacturing has enabled the integration of complex geometries directly into lightweight structures, providing opportunities in applications such as the aerospace and medical industry. Triply Periodic Minimal Surface (TPMS) lattice structures are of particular interest due to their geometry, which result in stretching and bending dominated zones within the same unit cell, contributing to excellent strength-to-weight ratio as well as energy absorption potential. There, however, exists a gap in the numerical simulation due to the difficulty in capturing intricate geometrical features and difficulty with the meshing of the lattice structure. In the following work, we evaluate several approaches to obtaining the mechanical properties like Young’s Modulus, Shear Modulus, Poisson’s ratio in the elastic region, and energy absorption as per ISO17340:2020 using the approaches of Periodic Boundary Conditions (PBCs), Symmetric Boundary Conditions (SBCs), and full-scale simulations of the Representative Volume Element (RVE). An approach to obtaining periodic meshes to apply PBCs or to build bulk lattices is also suggested. The material under consideration is graphene-reinforced AlSi10Mg, manufactured with PBF-LB/M, and the plastic behavior is characterized by the Johnson-Cook Plasticity Model. The performance of sheet-based TPMS lattices like Schwarz Primitive, Gyroid, Schwarz-Diamond, and IWP are compared with strut-based lattices like BCC and F2CC to quantify further the superior mechanical performance of TPMS lattices at volume fractions varying from 20% to 40%. The results from various approaches are documented and summarized to compare the mechanical properties obtained in conjunction with the computational effort required for each method, allowing for a comprehensive assessment of the most efficient and accurate simulation strategy.