Development of the Microstructure Based Stochastic Life Prediction Model
Abstract
The objective of the fatigue life prediction program at UCLA is to (1) ascertain microstructural features relevant to fatigue in aluminum 7050 alloys and develop quantitative methods for their characterizations, (2) characterize initial microstructures and accumulation of microstructural damage during fatigue of 7050-T7451 plate alloys and (3) formulate and test scaling relationships and models relating relevant microstructural features to fatigue damage in aluminum 7050 alloys. Emphases during the reporting period were on the completion of the metallographic and fractographic examinations of the high and low porosity 7050-T7451 commercial 6 plate alloys. Obtained results include quantification of the through thickness gradients of grain structures and volume fractions and size distributions of the constituent particles, pores and precipitates. To our knowledge this is the most complete set of microstructural data on the 7050-T7451 commercial plate alloys. Characterizations of the fracture surfaces and microstructures of fatigued samples are in progress. Up to date results include data on the change of surface roughness and fractal dimension with fatigue crack length and preliminary information about microstructural features on the crack path., Modeling has been focused on the predictions of the size distributions of the fatigue crack initiating pores and on the incorporation of the microstructural variables into existing fatigue life prediction models.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1993
- Accession Number
- ADA269742
Entities
People
- Annetta J. Luevano
- Jimin Zhang
- Marek A. Przystupa
Organizations
- University of California, Los Angeles