超高速撞击波阻抗梯度材料形成的碎片云相变特性

In hypervelocity impact, the wave impedance gradient material helps to transfer the kinetic energy into more internal energy, which causes the melting and vapor phase transition of debris cloud, and disperses and dissipates the kinetic energy of projectile, thus protecting the spacecraft from debris cloud. The wave impedance gradient material studied in this paper is made of titanium, aluminium and magnesium alloy(TAM). The smoothed particle hydrodynamics (SPH) method is used to simulate hypervelocity impact. Impact-induced phase transition criteria of various materials are given by using Tilloston equation of state and Steinberg-Guinan constitutive model. The simulated results were compared with the experimental results with impact velocity of 7.9 km/s. The results show that the impact-generated debris cloud is melted and vaporized to some extent when TAM wave impedance gradient material is impacted by the velocity more than 4 km/s. For Ti, Al and Mg, the debris cloud is melted at the impact velocities of 6 km/s, 5 km/s and 4 km/s, respectively, and it is vaporized at the impact velocities of 8 km/s, 9 km/s and 6 km/s.