Prediction of Printing Failure of a 3D Printed Drone Propeller using Fused Deposition Modeling

Fused Deposition Modeling (FDM) is a 3D printing process where thermoplastic materials are deposited in a layer by layer bottom up manner through an extrusion nozzle. Along with its advantage of manufacturing intricate geometries, the FDM printed part also has disadvantages like inter layer weak bonding, air gap etc. that lead to immature print and product failure. In this project, a drone propeller is used as an example to illustrate the print failure modeling strategy. SOLIDWORKS is used to generate the CAD model of the propeller and commercial finite element software package ABAQUS is used to simulate the FDM printing process and in-service performance of the propeller. In order to analyze the printing process, a heat transfer analysis is done first to predict the temperature history of the part, which drives the stress analysis for distortion and residual stress predictions. The tool path patterns dictate how material is added during the printing and it also have direct influence in the residual stresses in the part. Abaqus uses machine tool path as a direct input and solves the local orthotropic material properties and evolving cooling surfaces using the event series and progressive element activation technologies. With residual stresses and strains mapped from virtual printing simulation, in-service loading is also applied to predict the high stresses and displacements zone, which have higher possibility of failure. The results of the in-service condition of a 3D printed propeller is compared with a non-3D printed propeller, having same material properties and dimensions and in-service conditions. The comparison clearly shows that the 3D printed propeller has more stress all over the propeller body than the non-3D printed one, which make them more prone to breakage.