Abstract
Methods of treating initial and boundary conditions when applying the finite difference time domain (FDTD) numerical method to the analysis of elastic wave fields in anisotropic solids have been considered with reference to an electrical circuit analogy. It was found that the staggered lattice of the FDTD analysis of anisotropic solids is expressed by the superposition of two electric circuit networks of identical configurations. One of these circuits is translated relative to the other by one grid length in both the y and z directions, and is then superposed onto the other circuit to yield the final overall circuit. The two circuits are connected by the mutual capacitance between the capacitances loaded at the normal stress nodes of one of the circuits, and the shear stress nodes of the other circuit, which are positioned on the same stress nodes. From the configurations of the circuits, it can be concluded that the initial and boundary conditions should be applied to both the circuit networks. The theory was confirmed by considering two model problems.
