  This work outlines a new three-dimensional diffuse interface finite volume
method for the simulation of multiple solid and fluid components featuring
large deformations, sliding and void opening. This is achieved by extending an
existing reduced-equation diffuse interface method by means of a number of
novel flux-modifiers and interface seeding routines that enable the application
of different material boundary conditions. The method allows for slip boundary
conditions across solid interfaces, material-void interaction, and interface
separation. The method is designed to be straightforward to implement,
inexpensive and highly parallelisable. This makes it suitable for use in large,
multi-dimensional simulations that feature many complex materials and physical
processes interacting over multiple levels of adaptive mesh refinement.
Furthermore, the new method allows for the generation of new interfaces in a
conservative fashion and therefore naturally facilitates the simulation of
high-strain rate fracture. Hence, the governing model is augmented to include
ductile damage to allow for validation of the method against demanding physical
experiments. The method is shown to give excellent agreement with both
experiment and existing Eulerian interface tracking algorithms that employ
sharp interface methods.
