Crack Closure and Crack Growth Rate: An Empirical Model to Account for R.
Abstract
An empirical equation is proposed to account for stress ratio effects in fatigue crack growth based upon the crack closure concept. It is characterised by two fitted parameters. The new equation is used to establish effective stress intensity ranges for three sets of extensive crack growth rate data from the literature covering the stress ratio range -1 < or = R < 1. Least squares best fitted Paris equations are then used to predict crack growth lives fr comparison with the individual originals. Actual lives are almost invariably within the range from 1/3 to 2 times those predicted. The study shows that even better fits to the data would result from using a sigmoidal growth rate/effective stress intensity range relationship. This approach is being followed up.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1981
- Accession Number
- ADA112175
Entities
People
- G. S. Jost
- L. R. Gratzer