Optimum Design Using Multi-Objective GA for Multi-Layered Porous Sound Absorbing Materials

Abstract

An optimization method for multi-layered fabric sound absorbing structure is investigated using a multi-objective genetic algorithm (MOGA). Sound absorption coefficients of fabric materials are calculated by transfer matrix method using the Delany-Bazley model. For a feasibility study, a 3-layered-3-kinds structure of fabric materials was optimized, and results obtained by optimization agree well with experimental results. A 32-layered structure is thus optimized. The results show that relations between the layer pattern and frequency characteristics of absorption are consistent with the results of this 3-layered-3-kinds structure. Furthermore, the optimum flow resistivity distribution for noise reduction coefficient (NRC) is a ν shape, which is the same as the result obtained by using the gradient method.