Mechanical and thermal responses of random triply periodic minimal surface structures

Abstract

This study investigates the mechanical and thermal responses of stochastic Triply Periodic Minimal Surface (TPMS) structures fabricated using the laser powder bed fusion process with Ti-6Al-4V. Stochastic Gyroid structures were generated by introducing Voronoi-based randomness, allowing for controlled variations in stochasticity. Mechanical behavior was evaluated through finite element (FE) simulations with damage modeling and compressive testing, while thermal performance was analyzed using steady-state finite element modeling with periodic boundary conditions. Experimental and FE results demonstrated that increasing stochasticity alters failure mechanisms by dispersing deformation across sub-domains, reducing macroscopic shear band formation. Among stochastic structures, greater randomness from 5 to 50 random points led to an increase in elastic modulus, initial peak stress, and energy absorption by 38 %, 27 %, and 54 %, respectively. Additionally, while uniform TPMS structures exhibited higher effective thermal conductivity, aligning with the upper limit of Maxwell-Eucken’s models, stochasticity reduced effective thermal conductivity by approximately 8–16 %. Overall, although uniform Gyroid structures exhibited superior mechanical and thermal performance across all evaluated properties, these findings provide new insights into the trade-offs between mechanical resilience and thermal transport in stochastic TPMS architectures, highlighting their potential for multi-functional applications in automotive components, aerospace structures, and structural energy storage systems.