Honeycomb Sandwich Specimens Made of PLA and Produced Via 3D FDM Printing Process: An Experimental Study

Abstract

In recent years, the 3D Fused Deposition Modelling (FDM) technology, usually employed for the production of nonstructural objects, has been also used by the present authors for the production of small structural elements where the applied loads are moderate. A typical application could be the production of small Unmanned Aerial Vehicles (UAVs) where stresses are not excessive. In these cases, the FDM technique can use polymers such as Acrylonitrile Butadiene Styrene (ABS) and PolyLacticAcid (PLA). The present work is an extension of a past authors’ work where some sandwich configurations were proposed combining different materials (ABS or PLA) and different cores (homogeneous or honeycomb). In the present study, only PLA specimens embedding honeycomb cores are analyzed in order to understand if this selected lamination scheme could lead to an important weight reduction without significant decreases of mechanical properties. A capability analysis is performed on the geometrical parameters of the specimens (also comprising the weight) in order to investigate the stability of the printing process. A three-point bending test is conducted to evaluate the linear bending Young modulus and the ultimate bending stress. These mechanical properties are post-processed in order to conduct a capability analysis to propose the upper and lower specification limits to be used with confidence in appropriate structural analyses.