Damage Modeling Of Debris Cloud Produced By Hypervelocity Impact

The quantity of space debris increases with human's space activities development, and makes great threat to the orbit spacecraft. In order to ensure the safety in operation of orbital spacecrafts, especially the long duration and large size spacecrafts. Space debris and meteoroid shield are very important factors in the designing of spacecrafts. Debris cloud produced by space debris and meteoroid hypervelocity impact on bumper makes the threat of space debris and meteoroid to spacecrafts become debris cloud to module wall, therefore we must build a debris cloud model which describes the characterization of debris cloud, such as velocities, mass distribution and phase state, the damage of the module wall that produced by this debris cloud, and criterions and references for spacecrafts structure design.In this paper, using the theory of planar shock wave, we described the formation mechanism of the debris cloud. By comparion the simulation results with that of experiment, the validity of the SPH simulation in AUTODYN is verified, the characteristics of the debris cloud by a series parameters are analyzed, and the relationships of these parameters and impact parameters are obtained. The fitting equation of characteristic parameters are obtained by choosing suitable form of the equation. Based on the results of the experiments and simulations and the law of the characteristic parameters, we try to present a debris cloud model of Al projectile hypervelocity impact on thin Al bumper at normal incidence. A debris cloud model that contains shape, velocity and mass distribution is proposed. Equations of the debris cloud profile and model of velocity distribution are obtained considering the motion of debris cloud and simulation results. The area density model of the bumper material and the volume density model of the projectile material in debris cloud are also proposed considering the distribution of mass in experiments and simulations. The unknown parameters were determined through the mass, momentum and energy conservation equation. The stress which produced by the debris cloud model impact on the module wall is calculated using the momentum theorem in hydrodynamics. And the stress and the area of damage in the experiment are consistent, which verifies the validity of the debris cloud medel that can describe the debris cloud of normal impact and be used in the damage calculation of the module wall.