SEDL / STP / STP1321-EB / STP12319S

Development of a Rapid Thermomechanical Fatigue Test Method

Cook, TS
Lead Engineer, General Electric Power Generation, Schenectady, New York

Huang, HT
Engineer, General Electric Aircraft Engines, Cincinnati, Ohio

Pages: 15    Published: Jan 1997

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Abstract

Hot flowpath components of gas turbines can undergo thermomechanical fatigue (TMF), the simultaneous cycling of thermal and mechanical loads. The interactions between the two types of loads can produce damage mechanisms different than those observed during isothermal cycling. Models of this behavior, based on isothermal observations, need to be verified through TMF testing. In order to reduce temperature gradients, TMF tests are usually conducted at very slow frequencies, thereby requiring long testing duration to reach typical component lives. Given the expense and stability hazard of long tests, a method is needed to speed the production of TMF data. Such a method has been developed using an integrated air cooling-induction heating chamber. The test facility and the associated heat transfer and stress analysis required to analyze the test data are described.