Compressive enhancement gyroid lattice with implicit modeling implementation and modified G-A model property prediction

Abstract

Few easy-to-use methods for improving the compression properties of triply periodic minimal surface (TPMS) lattices with a constant solid volume fraction have been developed in earlier research. In this study, a design strategy for a TPMS lattice with cell-scale regional curvature differentiation was presented. The design strategy attempts to optimize the lattice mass distribution to increase the compressive load-carrying capability. The implicit functions-based implementation ensures the simplicity and applicability of the proposed method, and guarantees the smoothness of designed lattices. The finite element (FE) approach is adopted as the primary research instrument, and validated using powder bed fusion (PBF) fabricated samples. According to these findings, the curvature ratio—a key design parameter effectively regulates the plateau stress and energy absorption of the gyroid lattice. In the compressed direction, one of the as-designed lattices has an 25% increase in plateau stress. To enhance the compressive properties, the design strategy does not depend on altering the lattice deformation mode but rather on minimizing the stress concentration. A curvature ratio- and relative density-dependent constitutive equation derived by a modified Gibson-Ashby model is obtained and predict the plateau stress with < 5% average error.

Keywords

• Triply periodic minimal surfaces
• Curvature design strategy
• Plateau stress
• Compressive loading
• Implicit function