Accession Number:

ADA210084

Title:

The Effect of Transients on Crack Tip Stress Fields during Thermal Fatigue Loading

Descriptive Note:

Final rept. 1 Apr 1986-31 Mar 1989

Corporate Author:

CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF MECHANICAL ENGINEERING

Personal Author(s):

Report Date:

1989-04-25

Pagination or Media Count:

129.0

Abstract:

A method is developed for evaluating the effect of cyclic thermal loading on crack tip stress fields. In its development, advantage is taken of the periodic nature of fatigue loading and only harmonic loadings are considered. Formulating the problem in this way permits the extraction of time as an explicit variable and replaces its role with a dependence on the frequency of the thermal loading. The means for evaluating the effect of thermal transients on crack tip stress fields is the stress intensity factor which is calculated from numerically defined stress and displacement fields using a path independent integral. Results obtained indicate that stress intensity factors of cracked components exposed to thermal fatigue conditions have a significant dependence on the frequency of the thermal cycle and the crack geometry. Numerical estimates for Mode 1 thermal stress intensity have been obtained for the case of a titanium alloy that was heated using intense light sources. Thermal mechanical fatigue, Fracture mechanics, Thermal stress, Thermal transients.

Subject Categories:

  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE