Evaluation of Interpolative Modeling Concepts for Fatigue Crack Growth at Elevated Temperature
Abstract
This theses presents an examination of interpolative schemes for fatigue crack growth at elevated temperature (1200 deg F). An interpolative scheme involving the linear superposition of effects due to stress ratio, loading frequency, and peak load dwell or hold time, is applied to two state-of-the-art crack growth rate prediction models. SINH model is based on the hyperbolic sine function, and MSE model is based on a sigmoidal equation. The results of an experimental program are presented. Fatigue crack growth rate tests are performed on compact tension specimens according to ASTM standards. Two interpolative models are developed from the resulting data base. Additional tests are performed and the model predictions are compared to these additional tests. It is found that linear (on log-log scale) functional forms can be assumed to relate model constants to the test parameters (load ratio, frequency, and hold time). Also, it is found that these functional forms can be applied to both models. More work is needed to determine whether the effects of variations in each of the test parameters on crack growth rate are independent of each other and can be linearly superimposed. When the same functional forms are applied to the SINH and the MSE models, they behave much alike. Originator supplied keywords include: Fatigue; crack growth; high temperature fracture; charts; table(data); computer programs.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1984
- Accession Number
- ADA153222
Entities
People
- Gerald O. Painter
Organizations
- Air Force Institute of Technology