文档介绍：J. Construct. Steel Res. Vol. 37, No. 3, pp. 229-261, 1996
Copyright © 1996 Elsevier Science Ltd
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ELSEVIER
An Analytical Model for Fatigue Life Prediction Based
on Fracture Mechanics and Crack Closure
J. B. Ibs¢ & H. Agerskov
Department of Structural Engineering, Technical University of Denmark, Building 118, DK-
2800 Lyngby, Denmark
(Received 15 June 1995; revised version received 29 October 1995;
accepted 18 January 1996)
ABSTRACT
Fatigue in steel structures subjected to stochastic loading is studied. Of spe-
cial interest is the problem of fatigue damage accumulation and in this con-
nection, parison between experimental results and results obtained
using fracture mechanics. Fatigue test results obtained for welded plate test
specimens pared with fatigue life predictions using a fracture mech-
anics approach. In the calculation of the fatigue life, the influence of the
welding residual stresses and crack closure on the fatigue crack growth is
considered. A description of the crack closure model for analytical determi-
nation of the fatigue life is included. Furthermore, the results obtained in
studies of the various parameters that have an influence on the fatigue life,
are given. A very good agreement between experimental and analytical
results is obtained, when the crack closure model is used in determination
of the analytical fatigue lives. Both the analytical and experimental results
obtained show that the Miner rule may give quite unconservative predictions
of the fatigue life for the types of stochastic loading studied. Copyright ©
1996 Elsevier Science Ltd.
NOTATION
C Half length of physical crack; crack depth
C Crack growth coefficient
Ci Initial crack size
C Crack shape parameter
d Half length of effective crack
dc Crack growth rate
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230 J. B. Ibsa, H. Ag