Bending and compression behavior of 3-D printed PLA sandwich panels

This study investigates the bending and compression behaviors of FDM-fabricated polylactic acid (PLA) corrugated sandwich panels with symmetrical Y-shaped cores through combined experimental testing and finite element analysis (FEA). Core geometries with varying cell angles (60°, 75°, 90°), mid-lengths (2–10 mm), and cell numbers were systematically examined. Experimental results demonstrate that core angle and mid-length strongly govern bending stiffness, load capacity, and energy absorption, while compression performance is dominated by core stability and progressive crushing behavior. In three-point bending, the 60° core angle panel achieved the highest load capacity (1609 N) and specific energy absorption (0.14 J g −1 ), while increasing mid-length from 2 mm to 10 mm reduced strength by ≈23 %. Under compression, the specimen with a 60° core angle, 6 mm mid-length, and 4-cell configuration exhibited the maximum load capacity (16,953 N) and specific energy absorption (2.23 J g −1 ), outperforming other designs. Finite element simulations capture the global load–displacement response and dominant deformation patterns with deviations below 7 % in peak load. The novelty of this work lies in the coupled experimental–numerical evaluation of bending and compression behaviors within a unified geometric design space, revealing clear trade-offs between stiffness, strength, and energy absorption in FDM-fabricated PLA corrugated sandwich panels.