A novel mixed‐mode brittle fracture criterion for crack growth path prediction under static and fatigue loading

Abstract

In this paper, in order to predict the crack growth direction and fracture load under mixed modes I and II loading, a new criterion is proposed. For this purpose, after reviewing existing criteria, an effective stress is defined so as to include the influential stress components in fracture and exclude insignificant ones. Moreover, investigations show that most criteria predict a certain angle of fracture in pure mode II independent of material properties, although the experimental results are noticeably different for various materials. To solve this problem, effects of the ratio of fracture toughness for pure mode II to that of pure mode I are considered by defining a new material parameter. To verify the suggested criterion, after characterization of the newly defined material parameter, the predicted values using this criterion for the mixed‐mode conditions are computed. The predicted results show a good agreement with the experimental results.

Two basic approaches in a search of the crack propagation angle

“…). For example, the differences between shear and tensional strength of the material are included in the maximum effective stress criterion in searching the angle of crack propagation for mixed mode I/II loading . It should be also noted that fracture mechanics approaches are spread to estimate the crack propagation angle of a sub‐interface crack in the bi‐material …”

“…Possible fracture mechanics criteria for a search of the crack path can be found in the following references (e.g. [1][2][3][4][5][6][7][8][9][10][11]. For example, the differences between shear and tensional strength of the material are included in the maximum effective stress criterion in searching the angle of crack propagation for mixed mode I/II loading.…”

“…For example, the differences between shear and tensional strength of the material are included in the maximum effective stress criterion in searching the angle of crack propagation for mixed mode I/II loading. 6 It should be also noted that fracture mechanics approaches are spread to estimate the crack propagation angle of a sub-interface crack in the bi-material. 12 The approach based on the average tangential stress over the size of the fracture process zone in the vicinity of the crack tip can be also employed in a search of the crack propagation angle.…”

Predicting the crack path in a wedge under a concentrated tensile force by means of variational principle

“…(e.g. [1][2][3][4][5][6]). Integral approach allows predicting the crack path in general and can be based on a variational principle of fracture mechanics [7][8][9].…”

Simulation of Bending Fracture Process of Asphalt Mixture Semicircular Specimen with Extended Finite Element Method

“…Shahani and Tabatabaei assessed the e ect of specimen geometry on the T-stress value and e ect of T-stress on di erent fracture criteria [15]. Sajjadi et al proposed a novel mixed mode brittle fracture criterion for crack growth path prediction under static and fatigue loading [16]. Berto and Gomez investigated the possibility to use two fracture criteria in mixed mode fracture of notched components [17].…”