Sound velocity in a model elastic superlattice composite with two dimensional periodic modulations

摘要

In this article, I study, by means of numerical solution to the wave equation, the long-wavelength sound velocities for a model of two component elastic superlattice composite. The composite is defined by a periodic array of parallel infinite rods of one component embedded in another elastic medium. This is a superlattice with periodic modulations in two directions. The wave equation is solved numerically with a finite plane wave basis and is used to calculate the long-wavelength sound velocities for the lowest and second lowest energy modes. I study the convergence in the number of Fourier components used and extrapolate with a power law. The deviations of the sound velocity squares from the uniform limits are observed to be proportional to the squares of the elastic constant modulation amplitude for the small amplitude regime. I observe similar results for a range of parameters and composite geometries. (C) 2001 American Institute of Physics. References: 22