Numerical modeling of laboratory-scale asteroid impact based on elastoplastic flow model and CESE method

Asteroid impacts are destructive and low-probability threats to the Earth. The numerical simulation is considered an applicable analysis tool in asteroid deflection programs. As a novel shock-capturing strategy, the space-time conservation element and solution element (CESE) method can reliably predict shock waves and mechanical behaviors under high pressure and large strain conditions. In this paper, based on an elastoplastic flow model and an updated CESE scheme, the laboratory-scale iron asteroid impacts are modeled numerically, and the multi-material boundary treatment and the interface tracing strategy are introduced. Under hypervelocity impacts of the projectile to the iron asteroid target, the construction and realization of morphologies of impact craters and the implantation of projectile material into the target are numerically calculated. Numerical results show that the crater diameter and depth increase with increasing impact velocity and with increasing temperature, which softens the target. Computational results are compared with experimental observations available in the open literature, and good agreement is found. Therefore, the CESE method is successfully extended for capturing the key features of laboratory-scale hypervelocity asteroid impacts. (C) 2021 Author(s).