Bending behavior of 3D printed sandwich beams with different core topologies

Lightweight core topologies have been considered as an advanced alternative to improve the overall performance of sandwich structures in bending. Designed sandwich beams containing 3D printed cores as conventional honeycomb, re-entrant auxetic honeycomb with two positions of the cells, and chiral topologies were created with CATIA V5. The sandwich beams were manufactured from polylactic acid polymer (PLA) by fused deposition modeling (FDM) using the Ultimaker 3 Extended printer. Three-point bending testing was conducted on sandwich beams using an Instron 8872 testing machine and following ASTM C393-20, as to obtain the strength, bending stiffness, and energy absorption of the sandwich beams for these three designed core topologies. Comments on the cores' performance and sandwich beams response are done together with observations concerning their failure.