An investigation from raw components to composite: 3D printed Voronoi lattice core structured sandwich composite with woven glass fiber-epoxy outer layer

Abstract

A key emerging trend in mechanical engineering design involves adopting strategies that build lightweight lattice geometries, particularly for sandwich structures. These structures are characterized by low mass, a significant surface area to volume ratio, high porosity, and suitable mechanical behavior. This study focuses on the fabrication and investigation of thermoplastic polyurethane (TPU) Voronoi lattice core (V-core) structured sandwich composite with woven glass fiber (WGF)-Epoxy outer layer. The TPU V-Core structure was fabricated using the Fused Filament Fabrication (FFF) three dimensional (3D) printing method. Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, and Thermogravimetric Fourier Transform Infrared Spectroscopy (TG-FTIR) analyses were used to examine the interactions between the components within the sandwich composite structure. The experimental results demonstrated that the investigated structure has intricate interactions at the interface between the WGF-Epoxy outer layer and the V-core structure. The thermal stability and thermal degradation pathway of the composite and its components were also examined. In addition, three-point bending (TPB) tests were conducted on the sandwich composite and also on the core structures with plain rectangular prism and Voronoi lattice to assess their mechanical behavior.