Our latest article on MD simulations of shock propagation and spallation in polymers has been published in the Journal of Applied Mechanics:
https://doi.org/10.1115/1.4051238
In this article, we computed the spall strength of polyurethane samples by following two methods:
(1) The indirect method (from the free surface velocity history, which is commonly used in experiments)
(2) A direct method (from the atomic stresses in the spall region, which is possible only in MD)
The results reveal that the tensile strength computed from the indirect method is consistently smaller than the value obtained from the direct method. Moreover, the strength computed from the indirect method shows a noticeable agreement with the fracture nucleation stress.