Fatigue of Rene 41 Under Constant- and Random-Amplitude Loading at Room and Elevated Temperatures
Abstract
Narrow-band random-amplitude and constant-amplitude bending fatigue tests were conducted on sharply notched Rene' 41 specimens at room temperature, 700 degrees F (644 degrees K), and 1400 degrees F (1033 degrees K). When compared on the basis of the root mean square of the nominal peak stresses, the random loading generally gave shorter lives than the constant-amplitude loading. Theoretical life predictions were made for the random-loading tests by using the Palmgren-Miner cumulative-damage rule and two different peak stress distributions (the distribution determined from the tests and the classical Rayleigh distribution). The predictions under-estimated the fatigue life in practically all cases. The predicted lives based on the Rayleigh peak distribution were always less than those predicted by using the experimentally determined peak distribution. For both types of loading in the long-life region, a loss of fatigue strength from that at room temperature occurred at 700 degrees F (644 degrees K) but no further loss occurred at 1400 degrees F (1033 degrees K).
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1965
- Accession Number
- ADA455654
Entities
People
- Edward P. Phillips
Organizations
- National Aeronautics and Space Administration