Machining of thin-walled structures from stiffness driven additively manufactured preform geometry

Additive manufacturing provides the means to build component preforms with reduced excess material to create functional parts. In the case of aero structural and aero engine components, additive manufacturing technologies offer the possibility to substantially reduce the volume of material to be removed by machining operations. To achieve this objective, the preform must be built with the minimum material necessary to contain the final geometry and simultaneously provide enough stiffness to withstand the magnitude of the machining forces. This work describes a computationally efficient method to calculate the geometry required from the preform to reliably manufacture typical thin-walled structures via finish machining processes. This is achieved by defining the preform with near constant static stiffness across the width of the preform, in combination with, a prescribed magnitude of stiffness at the top edge of the preform. The prescribed static stiffness is the function of the machining force magnitude, a direct consequence of the pre-selected cutting conditions. This paper illustrates the application of the method to a straight single boundary thin-walled structure as introduction case and for ease of description.