Publication Date

2020

Document Type

Thesis

Committee Members

Joy Gockel, Ph.D. (Advisor); Onome Scott-Emuakpor, Ph.D. (Committee Member); Nathan Klingbeil, Ph.D. (Committee Member)

Degree Name

Master of Science in Mechanical Engineering (MSME)

Abstract

Additive manufacturing (AM) is convenient for building components with complex features. However, the long-term integrity of these components is uncertain, since AM parts have defects such as pores and rough surfaces. In this work, an analytical model was developed to determine the impact of defects, and a novel bending fatigue test was used to determine the fatigue life of channeled specimens. The analytical model, based off the theory of critical distances, investigates coupled pores and predicts their potential for fatigue failure. This resulted in a maximum allowable pore size and spacing recommendation for coupled defects. Additionally, specimens with through channels built using laser powder bed fusion were tested in high-cycle vibration-based bending fatigue. The resultant S-N curve and fractography studies revealed similar performance between the channeled specimens and the solid specimens. This research serves to increase understanding of additive defects and their influence on the fatigue life of AM components.

Page Count

118

Year Degree Awarded

2020

ORCID ID

0000-0002-2468-7818


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