Investigating How Additively Manufactured Parts in Traditionally Manufactured Systems Affect the System Dynamic Properties

Abstract

Additive manufacturing (AM) sits poised to make a large impact on the manufacturing sector. Expanding from their original application in rapid prototyping, AM parts are increasingly appearing in full production systems. Using AM parts as replacement parts has recently been touted as a way to save money and increase efficiencies in supply chains. While much work has been done exploring the properties of individual AM parts and how they might affect supply chains, very little has been done to investigate the impact of AM parts as components in a larger system. In fact, there appears to be a lack of research into how AM components affect the system vibrational properties when used as replacement parts. This work sought to answer this question by investigating the effects of replacing a steel bar in a four-bar mechanism with an AM polylactic acid (PLA) bar. Both static and dynamic testing were performed on the system when it was entirely steel, and when one part was replaced with an AM PLA bar. The static results indicated that the dominant modal frequencies of the system were not significantly impacted by the change, possibly suggesting that AM components may be used as replacement parts without concern for shifting modes of vibration. The dynamic data showed that the reduction of mass in the link helped reduce vibrations during operation, suggesting that some care should be taken in matching part properties between AM components and the ones they are replacing. The authors do urge caution in applying and interpreting these results, though, as they are preliminary and require further investigation. Because of this, the paper concludes with suggestions on how to expand and extend these results to fill the gap in the literature identified herein.