Corrections in numerical methodology to evaluate plasticity induced crack closure along the thickness.

Abstract

The influence of the three-dimensional effects of the distribution of the stress intensity factor in the numerical calculation of plasticity-induced crack closure is analysed in this paper. The usual methodology assumes a constant distribution of K along the thickness to obtain the effective stress intensity factor of the crack. This assumption should not be transposed to models that intend to observe phenomena in the crack front vicinity, where 3-D effects are a key aspect in the results. Through numerical simulations of both fracture and fatigue of through thickness straight cracks (CT specimen in mode I), the local opening and closure moment of each crack node is obtained and compared with previous one. Corrections are proposed for numerical methodology to obtain K⁠op and K⁠cl distribution along the thickness