Journal Published Online: 01 September 1976
Volume 4, Issue 5

A Damage Function and Associated Failure Equations for Predicting Hold Time and Frequency Effects in Elevated Temperature, Low Cycle Fatigue



A new approach is developed for predicting strain-controlled, low cycle fatigue life at elevated temperature using a proposed energy measure of fatigue damage. This measure of damage, defined as the net tensile hysteretic energy of the fatigue cycle, can be approximated by the damage function σTΔεp, where σT is the maximum stress in the cycle and Δεp is the inelastic strain range. The damage function is applied to predicting effects of hold time and frequency, when time-dependent damage occurs, through failure relations incorporating a variation of Coffin's frequency modified approach. Failure equations are developed for two postulated categories of time-dependent damage.

Author Information

Ostergren, WJ
Mechanics of Materials, Gas Turbine Products Division, General Electric Co., Schenectady, N. Y.
Pages: 13
Price: $25.00
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Stock #: JTE10520J
ISSN: 0090-3973
DOI: 10.1520/JTE10520J