Abstract
This research proposes a multi-material level set topology optimization method for the design of acoustic devices composed of acoustic media and a multi-elastic-material. First, we explain the two-phase material model that models the acoustic-elastic coupled system without imposing coupling boundary conditions. Next, the level set topology optimization method that can express multi-material distributions, the so-called Multi-Material Level Set (MM-LS) method, is introduced, in which we use two types of level set function. To incorporate the MM-LS method into the two-phase material model, the material parameters used in the two-phase material model are expressed using these two types of level set function. The proposed method is applied to a design problem for an acoustic structure that reduces the sound pressure level. The topological derivatives are computed using the adjoint variable method, and are used to update the level set functions. We construct an optimization algorithm, and numerical examples based on finite element analysis are provided to validate our proposed method.
