Session: 18-04: Failure Prediction & Life Assessment I

Paper Number: 154141

A Novel Accelerated Fatigue Testing Method for Rapid Additive Manufacturing Qualification 

Additive Manufacturing (AM) processes are more complex to control than traditional manufacturing approaches, and process variabilities can lead to fatigue performance variability. Specifically, key fatigue life factors such as microstructure, porosity, surface roughness, and residual stress can vary within a single build and/or within a single part, making fatigue life prediction difficult. Fatigue can lead to sudden and catastrophic failure phenomena. The possibility of these events must be thoroughly understood for critical turbine engine components like integrally bladed rotors. Understanding fatigue behavior for AM materials and processes requires hundreds of tests, and in many cases, data as high as one billion cycles to failure must be acquired. This means that the standard test methods for gathering fatigue life data would require roughly 600 days to conduct a single test that accumulates one billion fatigue cycles. Therefore, to rapidly scale the use of AM for turbine engine advancement and sustainment, a new accelerated fatigue testing method has been developed. The new fatigue test method is capable of gathering data >200 times faster than standard rotating bending and axial methods. This novel fatigue life capability has been demonstrated and compared against standard rotating bending and axial results for commonly sourced aluminum alloys as well as AM specific aluminum alloys. The results of the comparisons show strong correlations within standard normal prediction bands. Most importantly, the accelerated fatigue test method was able to gather 12 Aluminum 6061-T6 data points in only five hours of testing time while rotating bending gathered the same amount of data points in 99 days of testing.      

Presenting Author: Onome Scott-Emuakpor Hyphen Innovations

Presenting Author Biography: Dr. Scott-Emuakpor is the Founder and CEO of Hyphen Innovations, a spin out company from an Air Force Entrepreneur Program focused on R&D to improve structural aerospace parts. Dr. Scott-Emuakpor has over two decades of R&D experience on propulsion structural integrity. His work on material testing, design improvement, vibration mitigation, and additive manufacturing for structural aerospace parts have earned him many accolades, including a Presidential Award for Scientists and Engineers.

Authors:

Onome Scott-Emuakpor Hyphen Innovations
Philip Johnson Hyphen Innovations
Harshith Vadrevu Hyphen Innovations
Artur Ulsenheimer The Ohio State University
Calvin Stewart The Ohio State University