Date of Award
Master of Science in Engineering
Mechanical and Aerospace Engineering
Dr. Daniel Kujawski
Dr. Muralidhar Ghantasala
Dr. Jinseok Kim
Fatigue damage, surface roughness, hysteresis, strain-hardening, micro-hardness
Masters Thesis-Open Access
Fatigue is an essential consideration in the design of high performance, safety-critical structures, and components, as fatigue failure constitutes more than 70% of failures in dynamically loaded components. This research aims to shed light on the effect of surface roughness on the micro-hardness in metals through experimental techniques (Part 1), the correlation between the traditional fatigue testing and instrumented cyclic micro-hardness testing to determine the material properties modeled by Ramberg - Osgood relationship(Part 2), and the effect of the fatigue damage on micro-hardness and surface roughness (Part 3).
For this research, Al 7075 - T651 and Al 6061 - T651 chosen as the materials due to their vast range of applications in the aerospace industry for the fuselage, wings of airplanes, and in the automotive industry for engine radiators, wheels, body parts of the automobiles. Depending on the data acquired from all the experiments, the fatigue damage characterization can be evaluated using the surface roughness and the instrumented micro-hardness indentation measurements, which are aimed to predict the remaining life of components while at service.
Nikam, Suraj Sanjay, "Fatigue Damage Characterization by Surface Roughness and Instrumented Micro – Hardness Measurements" (2020). Masters Theses. 5128.