Optimization Strategies for the Design and Application of Titanium Structures in Aerospace Produced by Electron Beam Powder Bed Fusion

Abstract

Material optimization of structures is critical in aerospace applications where the overall performance and lifecycle cost is highly sensitive to the vehicle weight. The added complexity enabled by powder bed fusion additive manufacturing technologies provides engineers the ability to highly tailor the spatial arrangement of material for components. This work presents three case studies where optimization strategies were applied for a small thruster nozzle, a pod-mounted engine pylon, and turbine engine exhaust sandwich structure. The workflow process for each of these was unique, and required the implementation of design for additive manufacturing (DfAM) methods. In the case of the pylon, the central tapered box beam used a Solid Isotropic Material with Penalty (SIMP) method as a guide, before employing further optimization techniques to achieve an additional 7% weight reduction. Engine exhaust structures often use titanium sandwich material systems where bending stiffness was further optimized using a compliance minimization or stress minimization strategy, all while keeping weight constant. Examples of each were produced by electron beam powder bed fusion (EB-PBF), and the subsequent lessons learned are provided with regard to DfAM best practices.