Parametric Design and Mechanical Behavior of Hybrid TPMS Lattice Structures Based on Sigmoid Function

Hybrid design is a key method for optimizing the performance of triply periodic minimal surface (TPMS) lattices, where the relationship between configuration parameters and deformation behavior is critical for performance enhancement. In this study, a series of hybrid lattices were constructed based on Primitive (P) and Gyroid (G) lattices using Sigmoid function, with the weighting parameter ( k ) and volume proportion serving as key configuration parameters, and their mechanical responses were systematically analyzed. The weighting parameter inversely controls hybridization width and directly governs hybridization ‐ induced distortion. Higher k values yield narrower hybridization zones with greater distortion. Conversely, lower k values produce wider, smoother transitions with reduced distortion but significantly altered pore geometry. Both irregular pores and hybridization distortions induce stress concentrations, leading to nonuniform stress distributions. The mechanical behavior is primarily governed by volume proportion rather than weighting parameter. Under perpendicular loading, uniform crushing occurs with strain hardening. While parallel loading shows a transition from G ‐ dominated to P ‐ dominated graded crushing as the P ‐ content decreases, accompanied by a shift from pore buckling to strain hardening behavior. The balanced configuration ( k = 1, 50% P/G ratio) achieves optimal stress uniformity, deformation compatibility, and isotropic performance.