Investigation of failure criteria for a sharp notch

Abstract

In this study, a method of evaluating the static strength of a V-shaped notch based on the singular stress field at the notch tip is studied. The singular stress fields is defined by two parameters, K I,λ 1 and K II,λ 2 , which correspond to the intensities of symmetric stress field and the skew-symmetric field, respectively. Four kinds of fracture criteria are considered; two of them are based on the tensile strength σ B and the other two are based on the fracture toughness K I C . The usefulness of the criteria is investigated through the experimental results carried out on plane specimens of acrylic resin having a sharp notch for various notch configurations such as the opening angle, the inclined angle and the notch depth. It is shown that the criteria using stress intensity factor and the energy release rate not sensitive to the length of the virtual crack ε.

Brittle fracture of U-notched graphite plates under mixed mode loading

“…The strain energy density factor S [18] was defined as the product of the strain energy density by a critical distance from the point of singularity. Failure was thought of as controlled by a critical value S c , whereas the direction of crack propagation was determined by imposing a minimum condition on S. Several criteria have been applied mainly to sharp V-notched samples but also to U-notches [19][20][21][22][23][24][25] showing a different degree of accuracy with respect to the experimental results. Seweryn and Lucaszewicz reviewed the main criteria available under mixed mode loading [20].…”

“…Chen and Ozaki provided some interesting results under mixed mode loading. However, the prevalent mode during the test was mode I [23]. A modified maximum tangential stress criterion has been developed to predict the fracture toughness and fracture initiation angle in Ushaped notches under mixed mode loading or prevalent mode II loading [24,25].…”

Determination of mode II fracture toughness for U-shaped notches using Brazilian disc specimen

“…For mode I loading conditions and in the presence of sharp V-shaped notches, several fracture criteria have been suggested by Novozhilov (1969), Seweryn (1994), Leguillon (2001Leguillon ( , 2002, Gomez and Elices (2003a,b), Strandberg (2002), Yosibash et al (2004), Lazzarin and Zambardi (2001) and Zhang and Li (2008). However, there are very few mixed-mode I/II brittle fracture criteria for components containing sharp V-notches (see Dunn et al (1997aDunn et al ( ,1997, Seweryn and Lukaszewicz (2002), Yosibash et al (2006), Priel et al (2007) and Chen and Ozaki (2008)). Several mode I failure criteria have also been proposed and evaluated experimentally for rounded-tip V-notches and in the special case for U-notches (see Leguillon and Yosibash, 2003;Gomez and Elices, 2004and Gomez et al, 2006.…”

Fracture of V-notched specimens under mixed mode (I + II) loading in brittle materials

“…Several failure criteria have been proposed for V-notches (Seweryn and Mróz 1995;Seweryn and Lucaszewicz 2002;Yosibash et al 2006;Priel et al 2007Priel et al , 2008Chen and Ozaki 2008;Ayatollahi and Aliha 2009) and for U-notches (Papadopoulos and Paniridis 1988;Gómez et al 2007Gómez et al , 2008Gómez et al , 2009, providing more or less accurate predictions for the scarce experimental results.…”