  The Cellular Automaton (CA) modeling and simulation of solid dynamics is a
long-standing difficult problem. In this paper we present a new two-dimensional
CA model for solid dynamics. In this model the solid body is represented by a
set of white and black particles alternatively positioned in the $x$- and $y$-
directions. The force acting on each particle is represented by the linear
summation of relative displacements of the nearest-neighboring particles. The
key technique in this new model is the construction of eight coefficient
matrices. Theoretical and numerical analyses show that the present model can be
mathematically described by a conservative system. So, it works for elastic
material. In the continuum limit the CA model recovers the well-known Navier
equations. The coefficient matrices are related to the shear module and Poisson
ratio of the material body. Compared with previous CA model for solid body,
this model realizes the natural coupling of deformations in the $x$- and $y$-
directions. Consequently, the wave phenomena related to the Poisson ratio
effects are successfully recovered. This work advances significantly the CA
modeling and simulation in the field of computational solid dynamics.
