The features of the fracture of the aluminum alloy AMg4.5 under dynamic tension according to the Kolsky methods using Split-Hopkinson pressure bar are considered. Experimental and theoretical data of strength characteristics of the alloy in the initial coarse-grained and ultrafine-grained states are presented. It is shown that the high degree of deformation of the material obtained in the process of severe plastic deformation by torsion under high pressure has a negative effect on the dynamic strength of the material. Keywords: dynamic strength, incubation time criterion, Split-Hopkinson pressure bar, severe plastic deformation.

The problem of the determination of material strength properties through the Kolsky experimental technique is considered. Small size specimens of M1 copper alloy are tested on a split Hopkinson pressure bars equipment. The experimental data of tensile tests observed under both dynamic and quasi-static conditions are analysed within the framework of the incubation time criterion and the Sign-Perturbed Sums method. It is shown that the influence of a test performance error is considered in the data treatment procedure based on the developed method. Keywords: Dynamic strength, incubation time criterion, Kolsky bar system, Sign-Perturbed Sums method.