EXPERIMENTAL INVESTIGATION OF THE EFFECT OF CORE STRUCTURE AND LAYER THICKNESS ON THE FLEXURAL PROPERTIES OF 3D PRINTED PLA SANDWICH STRUCTURES

Authors : Betül Kaplan, Fatmanur İzmirli, Umut Can, Berkay Ergene

Pages : 405-417

Doi:10.46519/ij3dptdi.1681093

View : 232 | Download : 342

Publication Date : 2025-12-28

Article Type : Research Paper

Abstract :In recent years, the design and fabrication of lightweight structural systems have emerged as a significant area of interest within engineering applications. The multifunctional properties of sandwich structures—particularly their high bending strength, thermal insulation, and energy absorption capabilities—have facilitated their widespread adoption across various industries, including aerospace, marine, automotive, and construction. Additive manufacturing technologies offer considerable advantages over conventional manufacturing methods, particularly in enabling the fabrication of structures with complex core geometries. This study investigates the mechanical behavior of sandwich structures fabricated from polylactic acid (PLA) material using the fused filament fabrication (FFF) technique. The core sections of the sandwich structures were modeled in three different thicknesses using Autodesk Inventor Professional, and each configuration was manufactured at three distinct layer heights, resulting in a total of nine unique sandwich structure variants. To evaluate the influence of core thickness and layer height on mechanical performance, the specimens were subjected to three-point bending tests in accordance with ASTM D790 standards. Experimental results indicate that sandwich structures produced via FFF using PLA material exhibit high dimensional accuracy. Moreover, an increase in layer height led to enhanced bending strength, whereas increased core thickness relative to surface thickness was found to negatively impact the bending performance of the structures. Lastly, the highest flexural strength (73.5 MPa) was obtained with a 2 mm core and 0.3 mm layer thickness, while the lowest (25.8 MPa) occurred with a 4 mm core and 0.1 mm layer thickness.
Keywords : FFF, PLA, Honeycomb Sandwich Structure, Three Point Bending Test

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