ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 6

Fatigue Life and Crack Propagation Analyses of Welded Components Containing Residual Stresses

Smith, KN
Associate professor and associate chairman, and research assistant, University of Waterloo, Waterloo, Ontario

El Haddad, M
Associate professor and associate chairman, and research assistant, University of Waterloo, Waterloo, Ontario

Martin, JF
Assistant professorMember of ASTM, Michigan State University, East Lansing, Mich.

Abstract

This study deals with the fatigue of welded components emphasizing the use of small specimen data, a general stress-strain expression, the fatigue notch factor, and the effect of residual stresses. A computer-based fatigue damage analysis for welded structures is investigated; although accurate fatigue predictions have been made for notched structures, this type of analysis has not previously been applied to welded components. Fatigue crack propagation data are presented emphasizing the mean stress effect on the rate of cracking. Crack measurements have been made for both butt and fillet welded specimens in which the cracks commence from the toe of the weld.

For fillet welded attachments and butt welds with substantial reinforcement, a residual stress adjustment was made based on the assumption that the maximum stress at the notch root is equal to yield stress. A fatigue damage analysis for welded specimens subjected to block loading using a computer-based damage model gave results close to experimental data. With a proposed stress function as the controlling stress parameter for crack growth, crack propagation data were successfully correlated.

Keywords:
crack propagation, residual stress, stresses, fatigue notch factor, stress intensity factor

Paper ID: JTE11671J
DOI: 10.1520/JTE11671J
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