A Numerical Study of the Effect of Isotropic Hardening Parameters on Mode I Fatigue Crack Growth

Abstract

The consideration of plastic crack tip opening displacement (CTOD, δp), as a crack driving force has given us the opportunity to predict fatigue crack growth (FCG) rate numerically, and, therefore, to develop parametric studies focused on the effect of loading, geometrical, and material parameters. The objective here is to study the effect of the isotropic hardening parameters of the Voce law on FCG, which are the isotropic saturation stress, YSat, and the isotropic saturation rate, CY. The increase of these hardening parameters causes δp to decrease. However, this effect is much more pronounced for YSat than CY. The variation is non-linear, and the rate of variation decreases with the increase of isotropic parameters. The increase of YSat increases the crack closure phenomenon. Finally, the influence of the isotropic parameters is more relevant for pure isotropic hardening than for mixed hardening.

Keywords

• fatigue crack growth
• isotropic hardening
• crack tip opening displacement
• ctod
• crack closure