Abstract

This study investigates the mechanical performance of 3D-printed corrugated core sandwich panels under compression and bending loads through experimental and numerical methods. Initially, panels were fabricated with polylactic acid (PLA) skins and cores featuring triangular, trapezoidal, rectangular, and circular geometries. Experimental testing revealed that rectangular cores exhibited the highest compression strength, while triangular cores performed best under bending due to their superior stiffness-to-weight ratio. The circular and trapezoidal cores were found to maintain median performance under both compression and bending. Various failure mechanisms were observed within the corrugated core samples, including buckling, delamination, and core fracture. Subsequently, recycled polyethylene terephthalate (PET) foam inserts were added to the corrugated core channels to further improve the performance of the panel. The foam, recognized for its high strength-to-weight ratio, moisture resistance, and thermal insulation properties, significantly increased the compressive strength of the panels by 200-345% with only a 32.5% increase in weight. Similarly, the flexural strength improved by 170-267% while the weight increased by an average of 40%. The foam inserts delayed buckling, improved structural stability, and enhanced the ability of the panels to absorb energy under load. With the addition of foam failure, mechanisms such as foam fracture, densification, and foam shear were observed. Ultimately, finite element models were developed on ABAQUS for each core geometry. These models enabled the simulation of both compression and bending performance, evaluating the effect of change in geometric parameters and optimizing corrugated core structures. The model's predictions were validated against experimental results, showing good correlation and providing insight into how different geometries influence mechanical behavior. The simulation helps identify optimal designs for enhanced load-bearing capacity and energy absorption by adjusting core geometry. These results emphasize the importance of core geometry and foam inserts in optimizing sandwich panel designs for multi-functional and high-performance applications within diverse industries.