Mechanical characterization of green sandwich composites from kenaf fiber skins and sawdust core

This study presents an experimental and numerical characterization of a new sandwich composite made from Kenaf Fiber Reinforced Polymer (KFRP) and Sawdust Reinforced Polymer (SDRP). To this end, the KFRP skins and the SDRP core were fabricated and characterized in demand to acquire their constituent material properties. Bio-composite sandwich beams were manufactured and exposed to flexural load and flexural characteristics under three-point bending test. These beams’ force–displacement curves were acquired and the energy absorption mechanism for each beam was investigated. Numerical simulations were executed using the ABAQUS FEA code to support the investigational findings. The outcome of the core bio-composite shear stress sandwich panels showed a 13% increase as the thickness of the core grew from 10 to 20 mm, while that of facing bending stress experienced an increment of 13.93% as the thickness of the core size grew from 10 to 20 mm. The results of the failure investigation showed that sandwiches with a 10 mm core thickness failed too soon because of skin bending, rupture, and core delamination; sandwich structures with a 15 mm core thickness were able to withstand higher loads but also showed signs of material failure, including skin rupture and delamination and core shear failure. Compared to sandwich structures with 10- or 15-mm core thicknesses, those with 20 mm core thicknesses may tolerate greater bending pressures. It was also noticed that energy absorption of all sandwich beams increased as the core thicknesses increase. The numerical and the experimental force–displacement curves were found to be in good agreement.