| Abstract: | The displacement equations of motion for elastodynamics in 3 space dimensions are approximated by difference equations using 2nd order centred finite differences in space and time. The stability criterion of the difference scheme without boundary conditions is taken to be that condition on the ratio of step sizes which prevents the growth of an arbitray disturbance, and it requures the ratio of time step size to the space grid size to be less than a certain function of the ratio of the shear wave speed to the compressional wave speed. For this ratio less than 0.5, the condition is more stringent than that obtained by a simple extension from the two-dimensional case. |
