Variability in Room Temperature Fatigue Life of Alpha+Beta Processed Ti-6Al-4V (Preprint)
Abstract
In this program, smooth bar fatigue tests were conducted by several laboratories on the same lot of Ti-6Al-4V forged plate material. Multiple stress ratios and stress levels were tested to generate a fully populated stress-life curve. The tests, however, did not typically consist of many repeats. The approach of this work is to conduct a statistically significant number of repeated fatigue tests at a few loading conditions. A similar approach has been performed on several other turbine engine material systems often revealing a bimodal life distribution consisting of a number of low life specimens that may fail due to a separate mechanism. This paper will discuss the Ti-6Al-4V life distributions and sources of variability. Crack propagation using small crack growth data is used to predict the low life failures. Methods of modeling and predicting the life distributions will be discussed and demonstrated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2008
- Accession Number
- ADA489287
Entities
People
- John Porter
- Patrick J. Golden
- Reji John
Organizations
- Air Force Research Laboratory