  Measurements of the gravitational-wave signals from neutron star mergers
allow scientists to learn about the interior of neutron stars and the
properties of dense nuclear matter. The study of neutron star mergers is
usually performed with computational fluid dynamics codes, mostly in Eulerian
but also in Lagrangian formulation such as smoothed particle hydrodynamics
(SPH). Codes include our best knowledge of nuclear matter in the form of an
equation of state as well as effects of general relativity (GR). However, one
important aspect of neutron stars is usually ignored: the solid nature of their
crust. The solid matter in the crust is the strongest material known in nature
which could lead to a multitude of possible observational effects that have not
been studied in dynamical simulations yet. The crust could change the way a
neutron star deforms during a merger, leaving an imprint in the gravitational
wave signal. It could even shatter during the inspiral, producing a potentially
observable electromagnetic signal. Here, we present a first study of the
dynamical behavior of neutron stars with a solid crust and fixed GR background
with FleCSPH. FleCSPH is a general-purpose SPH code, developed at Los Alamos
National Laboratory. It features an efficient algorithm for gravitational
interactions via the Fast Multipole Method, which, together with the
implemented nuclear equation of state, makes it appropriate for astrophysical
applications. The solid material dynamics is described via the
elastic-perfectly plastic model with maximum-strain breaking. Despite its
simplicity, the model reproduces the stress-strain curve of crustal material as
extracted from microphysical simulations very well. We present first tests of
our implementation via simulations of neutron star oscillations and give an
outlook on our study of the dynamical behavior of the solid crust in neutron
star merger events.
