ORCID Identifier(s)

0009-0007-5475-5635

Graduation Semester and Year

Summer 2025

Language

English

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Mechanical Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Robert Taylor

Second Advisor

Joshua Mochache

Third Advisor

Ashfaq Adnan

Fourth Advisor

Emma Yang

Fifth Advisor

Amir Ameri

Abstract

This research aims to qualify the effect of design geometry on quality metrics of additively manufactured (AM) components that define reliability. Through the use of a novel methodology to characterize these quality metrics, AM components are inspected for the presence of defects such as surface roughness notches and porosity. These directly hinder the high-cycle fatigue characteristics demonstrated through the Kitagawa-Takahashi diagram and the El-Haddad model. By demonstrating the effect of geometry through a designed experiment and the adoption of the Murakami square root area parameter and Arola-Ramulu model, the improvement to fatigue life can be quantified. Incorporating this data into regression models, the interpolation of this data is then used to drive the design of a part towards an optimal design that minimizes mass but also respects the boundaries of the fatigue limit of the material. Furthermore, the dependence of porosity on the design geometry highlights the requirement to design coupons that are as geometrically similar to a final component as possible, otherwise possible non-conservative solutions may be adopted from the extrapolation of coupons that are not geometrically representative.

Keywords

Additive Manufacturing, Laser Powder Bed Fusion, Design Optimization, Reliability, Porosity

Disciplines

Manufacturing

License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Comments

I would like to acknowledge the effort of my supervising professor, Dr. Taylor, who supported me with not only his knowledge and guidance, but also by allowing me to explore a variety of topics and define what I wanted to do and how to accomplish it. The members of the dissertation committee, whose input was invaluable to the quality of this work, especially Dr. Mochache who met with me many times to provide his insights. The creation of the samples by the University of Dayton Research Institute, the characterization of the samples by Shimadzu Corporation, and the collaboration from Aerospace Corporation that helped build many of the concepts utilized here. Lastly, I want to acknowledge Dr. Jacob Rome, who gave me several chances to build myself professionally and academically through collaboration on our projects.

Included in

Manufacturing Commons

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