An Analytical Method for Predicting Direct Tensile Creep Fracture in Brittle Solids Containing Initial Microcracks

The tensile creep fracture behaviors in brittle solids are of great significance for the safety evaluation of brittle solid engineering. However, micromechanics-based tensile creep fracture behavior is rarely studied. In this study, a micromechanics-based method for predicting direct tensile creep fractures is presented. This method is established by combining the suggested expression of the mode-I stress intensity factor, the subcritical crack growth law, and the relationship between wing crack length and axial strain. This suggested mode-I stress intensity factor is formulated by the use of the basic theory of fracture mechanics under different loading modes. The rationality of the proposed tensile creep fracture model is verified by comparing with the experimental results. The correspondences of time-dependent axial strain, strain rate, wing crack length, and crack velocity are plotted under constant stress and stepping stress during tensile creep fracture. The effects of the initial crack size, inclination angle and density on the crack initiation stress, tensile strength, tensile creep fracture time, steady-state strain rate, initial strain, crack coalescence strain, and failure strain are discussed.

Automated summary

The study focused on the micromechanics-based tensile creep fracture behavior and presented a method for predicting direct tensile creep fractures. This method combines the suggested expression of mode-I stress intensity factor, subcritical crack growth law, and the relationship between wing crack length and axial strain. The rationality of the proposed tensile creep fracture model was verified by comparing with experimental results.