Author(s)

N. Kawagoishf, H. Nisitani, M. Goto & E. Kondo

Abstract

Axial loading fatigue tests were performed for an annealed 0.42% carbon steel at various stress ratios in order to investigate the effect of the stress ratio on the growth rate of a small crack. The ranges of crack opening displacement (ACOD) near the crack tip were similar under the same crack growth rate, regardless of the stress ratio, the stress level and the crack length. That is, /ICOD is the fundamental factor controlling the crack growth rate. The crack growth rate can be expressed by the equation, dlldN-o "/. The influence of stress ratio appeared as the change in the constants C and/or n. The parameter a "/ cor

Keywords