Regulating Triaxial Compressive Properties of 3D-Printed Corrugated Sandwich Structures by Lamination

Monolithic multi-layer V-corrugated sandwich panels with two distinct stacking configurations (overlapping and interlacing laminations) were additively fabricated via fused deposition modeling (FDM) using polylactic acid (PLA) filaments. Quasi-static flatwise compression testing demonstrates that interlacing laminates exhibit 50% greater flatwise compressive strength than their overlapping counterparts. Combined mechanical characterization and force transmission analysis demonstrate divergent failure mechanisms between the two configurations: interlacing laminates undergo core-dominated crushing failure, as their vertical load-bearing vertices are perfectly aligned; by contrast, overlapping laminates undergo face-sheet bending failure owing to staggered load-bearing points. During flatwise compression, interlacing structures exhibit progressive layer-by-layer collapse, which endows them with superior damage tolerance and energy absorption capability. In contrast, overlapping structures suffer sudden global catastrophic failure upon reaching the critical load threshold. A parametric tuning strategy targeting core wall thickness and interlayer sheet thickness is proposed to enhance the flatwise compressive strength of corrugated sandwich panels, and the underlying failure mechanisms are systematically validated. Benefiting from the core-crushing-dominated failure mode, interlacing laminates also deliver enhanced edgewise and sidewise compressive performance compared with overlapping designs. Nevertheless, the ultimate load-bearing capacity of both lamination designs is governed by the total number of stacked layers, whereas their compressive strength is primarily dictated by stacking geometry. This study clarifies how lamination stacking configurations modulate the triaxial compressive responses of microscale FDM-printed sandwich structures and delivers design guidelines for lightweight, high-performance 3D-printed sandwich panels.