Identifying Sensitive Parameters at Fatigue Crack Nucleation Sites Using Microstructural Simulation Models
Abstract
High strength components exposed to cyclic loading such as gas turbine disks fail in an insidious manner, giving no prior indication that damage has occurred. Cracking takes place on a very small scale and the critical damage state is reached when the crack is very small. Unfortunately, cracks of these sizes are difficult to detect. Often, long crack damage is considered when performing fatigue diagnostics. However, an accurate onboard prognostic capability should consider total life as initiation and long crack growth. Prognostication of small cracks requires simulating fatigue damage accumulation from the evolution of micro scale damage initiation. This paper discusses methods for predicting the probability of fatigue failure from cracks starting on the micro scale. These methods predict the variation in fatigue life based on the statistical variation in the microstructure of the material. Material parameters at the metallic grain level are integrated with fundamental physics-based models to predict the damage as it accumulates.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2006
- Accession Number
- ADA444474
Entities
People
- Animesh Dey
- Ganapathi Krishnan
- K. S. Chandran
- Robert G. Tryon