Development of an Impact Simulation Model for Pressurized Composite Overwrapped Pressure Vessels

This research presents the development of an impact simulation model for assessing the vulnerability of unshielded and shielded pressurized Composite Overwrapped Pressure Vessels (COPV) against non-spherical projectile impacts at speeds representative of low Earth orbit conjunctions. This paper discusses the COPV geometric model development, the material constitutive models used for the projectiles and COPVs, and the techniques for pressurizing the studied COPV to a quasi-equilibrium state prior to projectile impact. This work has been performed within Sandia National Laboratory's nonlinear structural dynamics simulation suite of tools, CTH. The simulation model has been verified to reproduce varying impact outcomes that has been produced in unshielded COPV testing including significant cratering, leak and burst. The goal of the developed models is to guide future non-spherical projectile testing and to extend those observations to conditions beyond ground test limits. This work is part of a broader effort being performed by the NASA Johnson Space Center to improve the safety and reliability of spacecraft in a more realistic representation of the orbital debris environment.