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Equivalent damage: a critical assessment
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Laflen, J. R. Cook, T. S. |
| Copyright Year | 1982 |
| Description | Concepts in equivalent damage were evaluated to determine their applicability to the life prediction of hot path components of aircraft gas turbine engines. Equivalent damage was defined as being those effects which influence the crack initiation life-time beyond the damage that is measured in uniaxial, fully-reversed sinusoidal and isothermal experiments at low homologous temperatures. Three areas of equivalent damage were examined: mean stress, cumulative damage, and multiaxiality. For each area, a literature survey was conducted to aid in selecting the most appropriate theories. Where possible, data correlations were also used in the evaluation process. A set of criteria was developed for ranking the theories in each equivalent damage regime. These criteria considered aspects of engine utilization as well as the theoretical basis and correlative ability of each theory. In addition, consideration was given to the complex nature of the loading cycle at fatigue critical locations of hot path components; this loading includes non-proportional multiaxial stressing, combined temperature and strain fluctuations, and general creep-fatigue interactions. Through applications of selected equivalent damage theories to some suitable data sets it was found that there is insufficient data to allow specific recommendations of preferred theories for general applications. A series of experiments and areas of further investigations were identified. |
| File Size | 6392218 |
| Page Count | 206 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19830009271 |
| Archival Resource Key | ark:/13960/t5t777d6v |
| Language | English |
| Publisher Date | 1982-11-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Propulsion And Power Service Life Damage Assessment Gas Path Analysis Fatigue Materials Gas Turbine Engines Data Correlation Crack Initiation Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
