Genetic Algorithm Optimization of Phononic Bandgap Structures
Rept. for May 2004-2005
ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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This report describes the use of genetic algorithms GAs for the optimal design of phononic bandgaps in periodic elastic two phase media. In particular, we link a GA with a computational finite element method for solving the acoustic wave equation, and find optimal designs for both metal-matrix composite systems consisting of TiSiC, and H2O-filled porous ceramic media, by maximizing the relative acoustic bandgap for these media. The term acoustic here implies that, for simplicity, only dilatational wave propagation is considered, although this is not an essential limitation of the method. The inclusion material is found to have a lower longitudinal modulus and lower wave speed than the surrounding matrix material, a result consistent with observations that stronger scattering is observed if the inclusion material has a lower wave velocity than the matrix material.
- Numerical Mathematics