Strain-based Cohesive Zone Model for a Crack in a Power-Law Material under Grossly Plastic Conditions.

摘要

To develop an analytical method for quantifying the growth behaviour of short cracks embedded in notch plastic zones for power law strain hardening materials, a strain-based cohesive zone model is proposed in which the conventional equilibrium equation in the stress-based model is replaced by strain compatibility. A comparison with finite element results shows that this strain-based model provides accurate values of the crack-tip-opening displacement for applied strains up to four times the yield strain under general yielding conditions. Furthermore, it is shown that the cohesive stress determined by a method proposed in this work gives better results than the existing method, which are appropriate only for small-scale yielding conditions.