SEDL / STP / STP982-EB / STP27198S

Fatigue Crack Closure: Observations and Technical Significance

Schijve, J
Professor of aircraft materials, Faculty of Aerospace Engineering, Delft University of Technology, Delft,

Pages: 30    Published: Jan 1988

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Abstract

The meaning of crack closure for fatigue crack growth resistance is discussed under different headings: (1) mechanistic aspects of crack closure—essential differences between microcracks and macrocracks, microstructural influences; (2) direct methods and indirect methods to measure crack closure; (3) numerical aspects of crack closure relations for constant-amplitude loading; and (4) crack closure and variable-amplitude loading. The paper summarizes the present state of the art. Attention is paid to microstructural aspects, changing crack growth mechanisms under threshold conditions and 3-dimensional aspects including plane strain/plane stress problems.