  In this paper we show for the first time the phenomenon of negative
reflection in a simple mechanical structure. The latter is a grating of fixed
inclusions embedded in a linear elastic matrix. Numerical analyses for
out-of-plane shear waves demonstrate that there exist frequencies at which most
of the incident energy is reflected at negative angles. The effect is symmetric
with respect to a line that is not parallel to the normal direction to the
grating structure. Simulations at different angles of incidence and
computations of the energy fluxes show that negative reflection is achievable
in a wide range of loading conditions.
