Design guidelines for additively manufactured stiffening structures to reduce vibrations in milling

Hybrid processes of additive and subtractive manufacturing offer designers the potential to develop complex, lightweight parts by additive manufacturing coupled with superior surface quality and tolerance by subsequent machining. The thin-walled additive structures tend to deflect while machining due to static and dynamic effects. With the design for additive manufacturing, additional stiffening structures can be included to reduce vibrations. This work investigates the design of additively manufactured stiffening structures for vibration reduction in the milling of thin-walled parts. A vibration analysis of a probe geometry is simulatively performed to identify significant design parameters. From the outer dimensions, the height of a stiffening structure shows the highest influence, followed by the length. With larger stiffening structures, the mass rises, so a tradeoff between deformation reduction and additional material is necessary. Over the parameters length, width, and height, the deformation can be reduced by a factor of 800 while a mass increase of 4.82 %. Stiffening structures shall be positioned against the excitation direction of the milling force. Over the parameters quantity, position, and distance, a deformation reduction of 185 for a mass increase of 7.11 % can be realized. The paper concludes with design guidelines for additively manufactured stiffening structures.