Dynamic stiffness modification by internal features in additive manufacturing

Abstract

Dynamic stiffness, or the product of the modal stiffness and damping ratio, is an important consideration for the design of additively manufactured parts that will experience dynamic loading. This paper describes a demonstration component which was designed and manufactured in two configurations using a metal wire arc additive process. The first configuration was an open channel structure, while the second contained a dynamic absorber in the internal cavity. Frequency response measurements of the two components showed a significant magnitude reduction for the modified component at the original open channel structure's natural frequency and an overall increase in dynamic stiffness. Polymer damping material was then added to further increase the dynamic stiffness.