Probabillistic Sensitivity Analysis in Life-Prediction of an alpha + beta Titanium Alloy
Abstract
Probabilistic sensitivities using the score function method are developed for a lifing analysis of an alpha + beta titanium alloy in a round bar under axial fatigue load. Sensitivities with respect to the statistical inputs of the crack initiation size (a), and Paris crack growth coefficient (C) and exponent (m) are developed with consideration of the correlation between the C and m. The sensitivities are obtained using a single Monte Carlo sampling analysis and do not involve finite difference approximations. The sensitivities indicate the importance of the random variable input parameters on the mean life and standard deviation of life and can be used as a basis for determining constructive data collection efforts. For this example, the crack growth intercept (C) is the dominate variable that affects mean-life and standard deviation of life, indicating that improved confidence in the results can be obtained most efficiently by improving the statistical characterization of C.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2008
- Accession Number
- ADA501729
Entities
People
- H. R. Millwater
- James M. Larsen
- Sushant K. Jha
Organizations
- Air Force Research Laboratory