Numerical analysis of a semi-circular disc with an angled crack loaded in mixed-mode

Abstract

A semi-circular disc with an angled crack loaded in mixed-mode (mode I + II) was chosen for a numerical analysis of crack deflection angles. Although the mode I of loading is often dominant in engineering praxis, lots of structures are subjected at least at the beginning of the crack propagation to a mixed-mode loading. Therefore, it is necessary to study the crack behaviour under such conditions and it has been shown that the multi-parameter fracture mechanics approach can be useful in this case of loading. Thus, various cracked configurations of the semi-circular disc were simulated numerically under three-point bending and a generalized form of selected fracture criteria is applied to calculate the crack deflection angle. It is discussed, which configurations can be safely described by means of the classical single-parameter fracture mechanics (i.e. only the stress intensity factors KI and KII controls the crack propagation), and which ones shall be analysed via multi-parameter fracture mechanics based on the Williams expansion. As the result, several configurations of the semi-circular disc with an angled crack under three-point bending are recommended to be tested experimentally in order to prove the results of the numerical simulations based on the finite elements.A semi-circular disc with an angled crack loaded in mixed-mode (mode I + II) was chosen for a numerical analysis of crack deflection angles. Although the mode I of loading is often dominant in engineering praxis, lots of structures are subjected at least at the beginning of the crack propagation to a mixed-mode loading. Therefore, it is necessary to study the crack behaviour under such conditions and it has been shown that the multi-parameter fracture mechanics approach can be useful in this case of loading. Thus, various cracked configurations of the semi-circular disc were simulated numerically under three-point bending and a generalized form of selected fracture criteria is applied to calculate the crack deflection angle. It is discussed, which configurations can be safely described by means of the classical single-parameter fracture mechanics (i.e. only the stress intensity factors KI and KII controls the crack propagation), and which ones shall be analysed via multi-parameter fracture mechanics based on the Williams expansion. As the result, several configurations of the semi-circular disc with an angled crack under three-point bending are recommended to be tested experimentally in order to prove the results of the numerical simulations based on the finite elements.