On the use of the critical distance concept to estimate tensile strength of notched components under dynamic loading and physical explanation theory

In the early works Yin et al. (2014) the reformulated approach based on Theory of Critical Distances (TCD) to estimate the strength of notched components subjected to dynamic loading was proposed. In the present paper, the efficiency of the proposed reformulation was demonstrated for the experimental data obtained for notched cylindrical specimens from structural steels (A57036, AISI 420 and AISI 321) and titanium alloy Grade 2 that were subjected the uniaxial tensile tests under the strain rate range of 10(-3)-10(4) s(-1). It was demonstrated that the extension of the TCD approach is capable of accurately estimate the strength of notched components subjected to dynamic loading (error +/- 20%). The second part of the work is devoted to the physical explanation of the critical distance theory, in particular the value of the critical length L, on the base of the original statistical-thermodynamic model of the defects evolution proposed ICMM UB RAS. It has been observed that the critical distance value can be considered as a fundamental length scale of dissipative structure growing in a blow-up regime. The application of the model is illustrated by numerical examples for model material (in the one-dimensional case) and titanium alloy Grade 2 (in the three-dimensional case).