Open Access

ARTICLE

Closure Effect Evaluation of Surface Crack Growth under Cyclic Bending using S-FEM

by

1 Tokyo University of Science, Japan.

Structural Durability & Health Monitoring 2010, 6(3&4), 289-304. https://doi.org/10.3970/sdhm.2010.006.289

Abstract

Crack closure effect on interaction of two surface crack growth processes by fatigue is studied. At first, change of C value in Paris' law along crack front of single surface crack is measured experimentally. It is shown that C value decreases near specimen surface. Crack closure effect is studied numerically for a surface crack by elastic-plastic cyclic analyses. It is found that closure effect appears more strongly near specimen surface than the maximum-depth point. By determining effective stress intensity factor including closure effect, it is shown that change of C value is equal to the change of closure effect along crack front. Using new C value considering closure effect, fatigue crack growth is predicted using S-FEM. It is shown that fatigue life and crack configuration agree well with experimental ones. Finally, interaction of two surface cracks is evaluated numerically, and it is shown that crack closure plays important role on the interaction of two cracks.

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