Abstract:

Impact cratering is an important surface process on most of the terrestrial planets in solar system. In this paper we described the impact crater formation mechanism, and then introduced the method of numerical simulation for crater study. We first expounded the basic theories and strategies of impact cratering simulation, during which we stressed that Equation of State (EoS) played an important role in the numerical simulation. However, compared to the varieties in the real world, only a few materials’ EoS is available and the substitution is inevitable in craters’ numerical simulation. We elaborated the concept and principle of substituting the EoS with that of another material that their Hugoniot curves should be similar, and we further analyzed the deviation of different physical quantities and ejection velocities from the substitution theoretically. Finally, we carried out numerical simulations to two small craters with targets of granite and quartzite,respectively, and the similarities with the deviations in peak pressure,temperature and densities are directly shown through the results. We think this kind of analyses could support future study in the field of planetary science, especially under the background that much more data would be transmitted from lunar, Mars, and other celestial bodies.

Key words: hugoniot curve, EoS, impact crater, numerical simulation