Distortional strain energy density criterion: the

T-stress effects in mixed mode I/II/III brittle fracture

“…In order to predict the crack initiation angles and investigate the crack propagation in mixed mode I/II loading, numerous theoretical criteria have been presented in the literature [1][2][3][4][5][6][7][8][9][10][11]. However, there are very few fracture criteria for spatial (out-of-plane) mixed mode problems including mixed modes I/III, II/III and specially general mixed mode I/II/III.…”

Investigation on the Applicability of Several Fracture Criteria to the Mixed Mode Brittle Fractures

“…NT criterion postulated that a crack propagates in the direction of maximum dilatational strain energy V,max along the contour of constant distortional strain energy ,0 when the distance from crack tip to the elastic-plastic boundary in the growth direction reaches a critical value ; that is, [9] also divided the total strain energy density into two components, the dilatational strain energy density V and the distortional strain energy density as…”

“…Hence, it is necessary to have an effective fracture criterion which can predict both crack initiation and crack propagation under mixed mode loading conditions. In the past decades, several criteria were proposed to investigate the mixed mode fracture phenomena, for example, maximum tangential stress criterion (MTS criterion, criterion) [1], minimum strain energy density criterion (MSED criterion, SED criterion, min criterion) [2], maximum energy release rate criterion (MERR criterion, max criterion) [3][4][5][6][7], maximum dilatational strain energy density criterion (NT criterion) [8], and distortional strain energy density criterion (Y criterion) [9]. Generally, these criteria used a singular stress field, and the singular stresses around a crack tip are presumed to be distributed in a manner that is independent of the applied load or the geometry of the structure.…”

Redirection of a crack driven by viscous fluid taking into account plastic effects in the process zone

“…We start from the maximum dilatational strain energy density (MDSED) criterion introduced in [20,26] to show that, in contrast to the classic fracture mechanics, this criterion in the case of hydraulic fracture does not always allow for predicting the direction of the crack propagation due to the problems with uniqueness and stability of solution. In particular, MDSED criterion fails to produce reasonable results in the proximity of the so-called viscosity dominated regime [16].…”