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Accession Number:
ADA278198
Title:
Microstructurally Based Model of Fatigue Initiation and Growth
Corporate Author:
ALUMINUM CO OF AMERICA ALCOA CENTER PA ALCOA TECHNICAL CENTER
Report Date:
1994-04-07
Abstract:
A model to calculate fatigue life is developed based on the assumption that fatigue life is entirely composed of crack growth from an initial microstructural inhomogeneity. Specifically, growth is considered to start from either an ellipsoidal void, a cracked particle, or a debonded particle. The capability for predicting fatigue life from material microstructure is based on linear elastic fracture mechanics principles, the sizes of the crack-initiating microstructural inhomogeneities, and an initiation parameter that is proportional to the cyclic plastic zone size. A key aspect of this modeling approach is that it is linked with a general purpose probability program to analyze the effect of the distribution of controlling microstructural features within the material. This enables prediction of fatigue stress versus life curves for various specimen geometries using distributional statistics obtained from characterizations of the microstructure. Results are compared to experimental fatigue data from an aluminum alloy.
Pages:
0019
Distribution Statement:
Approved for public release; distribution is unlimited.
Contract Number:
N00014-91-C-0128
File Size:
0.69MB
