I have finished preparing a rather complete set of finite element scripts devoted to the numerical simulation of sonic and phononic crystals. The scripts are written in the open-source language FreeFem++ (ff++). They can be downloaded here. The scripts are provided free of use (and without guarantee) to the scientific community. To show your support, please use the following citation (for instance) in your publications:
Vincent Laude, "Phononic crystal: artificial crystals for sonic, acoustic, and elastic waves" (De Gruyter, Berlin, 2015).