Continuum theory of porous materials with application to wave propagation calculations

A new theory of porous materials is considered, and the incorporation of this theory in a finite-difference Lagrangian wave propagation code, WONDY IV, is described. The results of plane-wave calculations carried out by using the linearized theory and a simple nonlinear model are then discussed for a polyurethane foam. The results for the linearized theory are in good agreement with an exact solution. The wave profiles calculated in the context of the nonlinear theory show a two-wave structure and are in qualitative agreement with experimental observations. 4 figures.