Electromagnetic and Mechanical Performance Analysis of Additive Manufactured Electric Machines Using Finite Element Simulations
CEME Collaborator Julia Zhang
Oregon State University
Additive manufacturing is opening up new ground for innovations in low-volume production due to faster and cheaper prototyping, reduced lead times, and shorter supply chains. This research focuses on numerical simulations to analyze mechanical and electromagnetic properties of an electric machine made with an additive manufacturing process. ABAQUS is the finite element analysis (FEA) tool used. The mechanical performance of a 3D printed electric machine has been analyzed and study of the electromagnetic properties is ongoing.
Laser beam melting (LBM), the additive manufacturing process investigated, melts metal powder into thin layers that forms a bond between two adjacent layers without melting them together completely. The bonding between these layers is the main concern for the structural integrity of 3D printed parts. The established method for studying crack propagation and fracture strength uses the J-Integral, a line integral on a path around the crack tip. This research applies a new method called cohesive zone. Fig. 1 shows a three-layered mesh with two cohesive zones. Instead of studying just the crack tip, we examine an area that could crack and determine the percentage of damage the interface has sustained. Fig. 2 shows the damage percentage between two adjacent layers at one moment while the rotor is spinning at 10,000 rpm.
Currently, FEA results indicate that at approximately 4,500 RPM, the cohesive zone between the layers is destroyed. This means a 3D printed rotor would not be able to handle the high angular velocities as a functional electric machine. A 3D printed metal part based on silicon steel has been acquired and will be used to validate the numerical models by performing tensile, buckling, and rotational testing. To gain a better understanding of the layering patterns, we will use a microscope to observe the cross-sectional area of the 3D printed metal part perpendicular to the layer building direction.