Cumulative damage laws for fatigue crack initiation and stage i propagation
- 1 October 1977
- journal article
- Published by SAGE Publications in The Journal of Strain Analysis for Engineering Design
- Vol. 12 (4) , 262-270
- https://doi.org/10.1243/03093247v124262
Abstract
A simple model for the demarcation of the initiation and stage I fatigue crack growth phases is introduced. Experimental cumulative damage data are used to determine the phase boundary between these two régimes, and an exponential accumulation of damage theory is invoked for each; here, damage is equated to crack length. Using both the model and the data, predictions are made of lifetime in double, treble and multilevel strain range tests. The theory successfully accounts for the load sequence effect, which is a consequence of the initiation period, and the effect of the difference between successive strain range levels. It is suggested that the Palmgren-Miner expression be replaced by individual expressions for the accumulation of damage in the separate phases of initiation and stages I and II fatigue crack propagation.Keywords
This publication has 9 references indexed in Scilit:
- Influence of a zero-load rest period in elevated-temperature fatigueThe Journal of Strain Analysis for Engineering Design, 1976
- Cumulative Damage in Fatigue under Multiaxial Stress ConditionsProceedings of the Institution of Mechanical Engineers, 1974
- Random Load Fatigue Damage Accumulation in Mild SteelProceedings of the Institution of Mechanical Engineers, 1973
- A Theory for Fatigue Failure under Multiaxial Stress-Strain ConditionsProceedings of the Institution of Mechanical Engineers, 1973
- Cumulative Fatigue Damage Under Stress-Controlled ConditionsJournal of Basic Engineering, 1971
- Cyclic behaviour of materialsJournal of Strain Analysis, 1970
- A theory of fatigue crack growthInternational Journal of Fracture, 1967
- Application of a Double Linear Damage Rule to Cumulative FatiguePublished by ASTM International ,1967
- An Observation Concerning the Cycle Ratio in Cumulative DamagePublished by ASTM International ,1960