| dc.contributor.author | Suman, Sandip Kumar | |
| dc.description.abstract | Fatigue is considered to be one of the most frequent phenomena in the failure of many
machine parts. Most of the prior studies on fatigue have been limited to uniaxial loading cases
with a primary focus on constant amplitude cycles. A detailed exploration of multiaxial fatigue
under constant and variable amplitude loading scenarios for a wide variety of aircraft engine
alloys has been performed in this study, and a new methodology for the accurate prediction of
fatigue damage is developed. A critical-plane based constant amplitude fatigue damage model
has been developed in this study which is simple in comparison to prior models developed by
other researchers and reduces the computational effort. The constant amplitude fatigue damage
model is further used in the development of a multiaxial variable amplitude damage estimation
method, with an emphasis on estimating the damage created by both low cycle fatigue (LCF) and
high cycle fatigue (HCF) cycles. A significant increase in overall fatigue damage was observed
in the tests with the introduction of HCF cycles in the mission histories. The damage due to the
HCF cycles has been found to be much greater than predicted by linear damage accumulation
theories, although the degree of interaction between the LCF and HCF cycles was found to be
very dependent on the multiaxial load paths. In addition, the HCF cycles did not contribute
significantly to the accumulation of damage until a certain amount of “pre-damage” had been
caused by the LCF cycles. Separate HCF damage computing approaches have been adopted in
this study to accurately compute the damage produced by tensile and shear dominant HCF
cycles, and a significant improvement in the accuracy of fatigue life prediction has been
achieved using the new methodology. | en_US |
| dc.publisher | North Dakota State University | en_US |
| dc.rights | NDSU Policy 190.6.2 | |
| dc.title | Nonlinear Fatigue Damage Accumulation in Aircraft Engine Alloys Multiaxial Loading | en_US |
| dc.type | Dissertation | en_US |
| dc.date.accessioned | 2017-11-28T14:19:39Z | |
| dc.date.available | 2017-11-28T14:19:39Z | |
| dc.date.issued | 2013 | |
| dc.identifier.uri | https://hdl.handle.net/10365/26885 | |
| dc.description.sponsorship | General Electric (Aviation) | en_US |
| dc.description.sponsorship | Airforce Office of Scientific Research | en_US |
| dc.rights.uri | https://www.ndsu.edu/fileadmin/policy/190.pdf | |
| ndsu.degree | Doctor of Philosophy (PhD) | en_US |
| ndsu.college | Engineering | en_US |
| ndsu.department | Mechanical Engineering | en_US |
| ndsu.program | Mechanical Engineering | en_US |
| ndsu.advisor | Kallmeyer, Alan | |
