Model of the brittle crack growth under the combined mode loading.

Abstract

The modified model for dynamic crack growth in viscoelastic material has been proposed. The model based on the structural approach that includes Zhurkov’s thermokinetical concept and Neiber-Novozhilov’s criterion of brittle fracture. The structural approach describes the microstructure inhomogeneity of material and staging of crack propagation revealing by optical and electronic fractography as changing the scale of damage accumulation and fracture. The main parameters of the physical model approved by experimental data on the pulse hit action of striker to a notch of the permanently hardly loaded single edge-notched specimen in wide range of environment temperatures has been analyzed in the paper. The proposed model of brittle crack growth under the dynamic blow influence based on physical representations of the fluctuation nature of the fracture process and enables a description of the transition from discrete experimental data under combined loading to a set of continuous numerical data sufficient to calculate the values of the crack tip energy flow in a wide range of external loading and extreme environment, including the low temperatures.