Topology Optimization and Additive Manufacturing-based Parts Consolidation of an Aircraft Avionics Pedestal
An avionics pedestal is the structure located in the center of the cockpit that houses the flight controls and critical electronics for the operation of the aircraft. This thesis presents a parts consolidation design approach, incorporating topology optimization-based design for additive manufacturing, applied to the center avionics pedestal for a Bombardier business jet with the objective of reducing the component count, joint count, assembly time and total unit cost. The current pedestal design is limited by the use of traditional manufacturing methods and materials, making it a great candidate for this redesign process. The redesign process began by simplifying the model of the original pedestal to create a design space that accounted for assembly and maintenance constraints, as well as the spacing required for the electronics and controls. Topology optimization was performed to aid the parts consolidation and additive-manufacturing based re-design process by providing the most efficient material layout to generate initial designs, based on the pilot effort limit loads and emergency loads applied to the structure. Next, the preliminary designs were carried through a design refinement stage where additional design optimizations of free-size and lattice optimization were performed to achieve mass reductions. These structures were then verified using a linear-static stress analysis against the certification loads. The final redesigned pedestal consisted of an outer sheet metal enclosure, and two polymer additively-manufactured components comprising the interior of the pedestal to support the avionics themselves. The two additively-manufactured parts replaced a large number of previously machined metallic components, resulting in a 72% reduction in part count and a 44% reduction in joint count. The reduction in part count and joint count resulted in a cost reduction for the redesigned pedestal, meeting the main objectives of the project and highlighting the benefits of using this approach for future aircraft design.