Fire Growth Behavior and Predictive Modeling of 3D-Printed Triply Periodic Minimal Surface (TPMS) Porous PLA Structures

Triply periodic minimal surfaces (TPMSs) are increasingly used in thermal management systems due to their high surface area and interconnected porous architecture. However, how TPMS geometry influences fire growth remains poorly understood. Herein, Gyroid, Diamond, and Schwarz-P PLA structures were fabricated through additive manufacturing, and their fire behavior was characterized via cone calorimetry. Univariate experiments demonstrate that flame propagation is primarily governed by cell structure, rather than porosity or specific surface area. The orthogonal array L9(33), covering three factors of wall thickness, cell size and cell type (Gyroid, Diamond, and Schwarz-P), indicates that their effects on the flame growth index (FGI) rank as: cell size > unit cell > thickness. Meanwhile, a multivariate regression model was developed to predict the FGI of TPMS porous PLA, exhibiting high prediction accuracy (R2 = 0.95) and low residual standard deviation. These results provide quantitative insights into the correlation between TPMS geometric features and fire growth, which facilitates the design of safer porous structures for thermal management applications.