Optimal face sheet thickness of 3D printed polymeric hexagonal and re-entrant honeycomb sandwich beams subjected to three-point bending

Abstract

This study sheds light on designing optimized 3D printed polymeric sandwich beams by utilizing the practical aspect of the failure mechanisms. Obtaining an optimal face sheet thickness based on the static failure mod map is the main aim of this work. In order to achieve this purpose, the performance of 3D printed hexagonal honeycomb and re-entrant honeycomb sandwich beams, which were fabricated by the fused deposition modeling (FDM) technique, with four specific face sheet thicknesses under three-point bending were assessed. The mechanical behaviors were evaluated using the extended finite element method (XFEM) in ABAQUS software, and the digital image correlation (DIC) analyses were employed to display the cracks that are not visible to the human eye. The numerical results with less than 6.6% error were confirmed with experimental ones. The current meticulous investigation discloses that the static failure map of a 3D printed polymeric sandwich beam with multi-row cellular lattice core is divided into face fracture and core shear modes, which has not been reported yet. The tremendous achievements provide novel insight into determining an optimal face sheet thickness and its relation with the growth rate of energy absorption capacity. Experimental investigation reveals that increasing face sheet thickness by one millimetre from H 2 to H 3 and R 2 to R 3 enhances energy absorption capacity by about 11% and 19.8%, respectively.