Enhancing the dependability and power density of a SPMSMs is crucial for its extensive utilization in the automotive and aerospace sectors. One major concern regarding these machines is the significant thermo-mechanical loads experienced by the overall rotating assembly due to high rotational speeds and a wide operational temperature range from $50^\circ C$ to $150^\circ C$. This poses a considerable challenge in maintaining structural integrity among the components. Redesigning components to reduce assembly complexity and weight necessitates careful consideration of boundary conditions and contact modeling to prevent catastrophic failures like magnet fly-by conditions. To reduce model complexity, a simplified approach involves integrating the hub and shaft; both machined from AISI 4340. Additionally, the application of a carbon fiber sleeve is investigated through 3-dimensional composite modeling to enhance structural integrity. The primary objective of this thesis is to scientifically justify the design and validation of an integrated rotor hub and shaft using efficient FEM and integration strategies, with the aim of maximizing the durability of a $150kW$ radial flux SPMSMs spinning at $20,000 rpm$. The integrated topology optimization is evaluated using a multiphysics platform alongside studies on motor assembly eigenfrequency. By employing the integrated approach and utilizing AISI 4340 for both the shaft and rotor hub, a weight reduction of $1.84kg$ is achieved, eliminating the need for standard components such as balancing end clamp plates, locknuts, and washers. Furthermore, introducing a carbon fiber sleeve enhances structural integrity, thereby reducing adhesive stress. The design and optimization of the rotating components ensure that the maximum von Mises stress is $50\%$ lower than the material's yield strength. Reduced masses lead to lower centrifugal forces, thereby diminishing radial stress and promoting component and assembly stiffness. / Thesis / Master of Applied Science (MASc) / This thesis aims to increase the reliability and power density of a surface-mounted permanent magnet synchronous machine (SPMSMs), a commonly used traction motor in the automotive and aerospace industries. One of these machines' main challenges is designing their components to withstand the high mechanical loads caused by their fast rotational speeds. The studies performed in this thesis use a computer modeling technique called Finite Element Modeling (FEM) to strategize and design an integrated rotor hub/shaft by maximizing the durability of a 150kW radial flux SPMSMs rotating at 20,000 rpm. Upon evaluating the integrated design using a variety of physics-based simulations, the design was found to save 1.84kg in weight, reducing centrifugal forces and improving the overall stiffness of the motor assembly. This research could lead to more efficient and durable electric SPMSMs for various applications.

The development in additive manufacturing methods has cleared the path for topology optimizationby making it possible to produce complex geometries, which would not be possible to produce bytraditional manufacturing methods. Topology optimization uses iterative structural computations tond an optimal material distribution given a maximum optimization domain, load cases and/or otherstructural criteria. The relation between retained mass and structural performance of a swing armfor the vehicle BvS10 was examined for two different materials. The first material was an estimate of an additive manufactured material and the other for a high structural steel. Given the extreme load cases, the geometrical limits of the swing arm and by specifying how much mass was to be retained the stiffness was to be maximized. The optimization was performed using an elastic material model in thecommercial software ANSYS. This elastic material models was based on standard material parameters of steel. Three geometries were generated, namely OG100, OG90 and OG80, which corresponded to 101 %, 87 % and 81 % of the mass of the original swing arm, respectively. The optimization procedurewas combined with geometry modications in SpaceClaim to simplify the obtained geometries. All these geometries consisted of a hollow geometry with a greater width compared to the original geometry. The geometries were then evaluated using multilinear plastic material models based on respective material. Using the additive manufactured material model no generated geometry could perform structurally better than the original swing arm. This indicates that greater material properties must be obtainedin order to be able to reduce the weight of the swing arm. By using the material properties of the highstructural steel, it was found that at least 31.3 kg per vehicle could be reduced by using the optimizedgeometry OG80, and still not perform structurally worse than of the original swing arm. / Utvecklingen inom additiv tillverkning har öppnat vägen för topologioptimering genom att kunna producera komplexa geometrier, som inte skulle vara möjliga att tillverka med hjälp av traditionella tillverkningsmetoder. Topologioptimering använder iterativa hållfasthetsberäkningar för att finna den optimala materialfördelning givet en maximal optimeringsdomän, lastfall och/eller andra strukturella kriterier. Relationen mellan bibehållen massa och strukturella prestationer hos en pendelarm till fordonet BvS10 har undersökts för två olika material. Det ena materialet var en uppskattning av ett additivt tillverkat material och det andra materialet var ett höghållfasthetsstål. Givet dem extrema lastfall, geometriska begränsningar hos pendelarmen och genom specficera hur mycket massa som skulle behållas så skulle styvheten maximeras. Optimeringarna utfördes med en elastisk materialmodell i den kommersiellamjukvaran ANSYS. Denna elastiska materialmodell var baserad på klassiska materialparametrarfor stål. Tre geometrier genererades. Optimeringsproceduren användes i kombination med geometriska modikationer i SpaceClaim för att förenkla de optimierade geometrierna. Dessa var OG100, OG90 och OG80, vilka motsvarade 101 %, 87 % och 81 % av pendelarmens originalvikt. Alla geometrier bestod av en ihålig geometri med större bredd än originalarmens. Geometrierna utvärderades sedan med hjälp av multilinjära plastiska materialmodeller baserat på respektive material. Ingen av dessa geometrier kunde prestera bättre än originalarmen när det additivt tillverkade materialet användes. Detta indikerar att bättre materialegenskaper måste uppnås för att kunna reducera vikten hos pendelarmen. Genom attanvända höghållfasthetsstålet upptäcktes att åtminstone 31.3 kg per fordon kunde reduceras genom attanvända OG80, och fortfarande inte prestera sämre än originalarmen.