Spall fracture of copper under loading by shock waves with duration less 1 microsecond

Abstract

The paper presents results of experimental researches on spall fracture of polycrystalline copper when loading by shock waves with intensity of 20–33 GPa and duration < 1 μs. It is shown that decrease of copper spall strength is observed behind SW front at SW intensity of ∼ 33 GPa (above threshold of formation of heterogeneous deformation bands). When reducing SW intensity to 27 GPa, spall strength is restored. Duration of the softened copper state does not exceed ∼ 0.5 μs. The method for spall strength evaluation is based on measurement of maximum damage in post-test samples.