Electronic Theses and Dissertations





Document Type


Degree Name

Bachelor of Science


Mechanical Engineering


Mechanical Engineering

Committee Chair

Ali Fatemi

Committee Member

Gladius Lewis

Committee Member

Reza Molaei


One of the principal challenges that limits wide adoption of additively manufactured (AM) metals is their ill-understood fatigue behavior. The present study investigated the correlations between material properties, and the defect size effects on the fatigue performance of three groups of AM metal samples. In Group 1, the samples were machined and lack substantial internal defects. In Group 2, the samples were also in the machined surface condition but had internal or surface connected defects. Lastly, in Group 3, the samples were left in their as-built surface condition and may or may not contain internal or surface connected defects. Based on these correlations, some methods are proposed for constructing approximate S-N lines. The goal of these approximation methods is to provide reasonable correlation between the fatigue performance of components manufactured of AM metals, and easily and inexpensively obtainable properties like hardness, ultimate tensile strength, and defect characteristics. The proposed methods have been shown to produce reasonable first order approximations for the purpose of determining the viability of implementing AM metals in the manufacturing of components. However, these methods are limited in their accuracy and therefore might not produce sufficiently accurate results for some applications.


Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.