Accession Number:

ADA461511

Title:

Corner Crack Propagation in the Presence of Residual Stresses (Preprint)

Descriptive Note:

Conference paper

Corporate Author:

DAYTON UNIV OH RESEARCH INST

Report Date:

2006-05-01

Pagination or Media Count:

12.0

Abstract:

BA technology development program known as Engine Rotor Life Extension ERLE has been initiated by the United States Air Force. One of the key technologies being assessed under the ERLE program is the analysis of 3D crack propagation at critical locations in turbine engine components. These critical locations are typically shot peened requiring the ability to predict 3D crack propagation at stress concentration sites in the presence of residual stresses. Hence, a study was conducted to characterize and analyze a corner crack emanating from a notch in a Ni-base superalloy in the presence of shot-peen induced residual stresses. Finite element analysis of the corner crack propagation was performed using 3D codes, ZENCRACK and FRANC3D. Initial elastic-plastic analyses were conducted to account for plasticity-induced residual stresses at the notch. Prediction of 3D crack propagation was conducted with and without shot peening induced residual stresses for comparison with experimental results. The corner crack growth predictions correlated well with the experimental results for baseline and shot-peened specimens. Significant increase in crack growth life due to shot-peening was successfully predicted using the 3D fracture mechanics codes. The modeling of the relaxation of residual stresses due to thermal exposure and the non-linear mechanical loading was essential for accurate prediction.

Subject Categories:

  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE