Specific features of the damage nucleation stage under severe loading of copper

The nucleation and evolution of damage in annealed coarsely crystalline M1-type copper subjected to fast loading to a pressure P ∼ 32 GPa, followed by the action of tensile stresses σ p with an intensity of ≈−2.0 GPa for a time t ≈ 0.3–1.5 μs, have been investigated numerically and experimentally. It has been shown that, at a specific combination of amplitude-time characteristics of the tensile stress pulse, damage localization in some cases at t < 1 μs has been observed in zones (∼10–14 mm in size) alternating with “dead” zones (∼3–5 mm in size) containing no visible damages. Pores are connected by “yield streamlets.” The existing multistage models of fracture kinetics have neither explained nor predicted the formation of a “band” damage structure or the presence of “yield streamlets” in specimens.