Numerical analysis of spall response in aluminum with helium bubbles

The creation of helium atoms is one of the main damaging mechanisms in neutron irradiated metals and is therefore a major concern in related scientific research. Recent researches under static loading conditions showed that the creation of helium atoms in metals is of great academic significance, for their precipitation into bubbles can cause substantial deterioration of the mechanical properties of materials. In this paper, based on experimental results so far published, a damage model is adopted combining inertial effect, initial void size and damage, to investigate the influence of helium bubbles in aluminum on its dynamic spall properties. The numerical calculation results show that the damage growth is insensitive to the pressure inside the bubble and the temperature produced by plastic deformation; the inner stress decreases more quickly and the porosity increases more slowly with the increase of the initial damage; the damage increases more slowly with the increase of the initial size of the helium bubble due to the inertial effect. Therefore, the study on the spall response of metals with helium bubbles should focus on the initial size of the helium bubble, the initial damage and the inertial effect at high loading rates.