실내소음제어를 위한 압전지능구조물의 최적설계

초록

Optimal design of a piezoelectric smart structure is sudied for cabin noise control. A cubic shaped acoustic cavity with a flat plate which covers one side of the cavity is taken as the problem. The sensor signal is returned to the actuator through a negative gain. The acoustic cavity is modeled using the modal approach which represents the pressure fields in the cavity as a sum of moe shapes of the cavity with unknown coefficients. By using orthogonality of the mode shapes of the cavity, finite element equations for the structure with the influence of the acoustic cavity is derived. The objective function is the average pressure at a certain region, so-called silent zone, in the cavity and the design variables are the locations and sizes of the piezoelectric actuator and sensor. The optimal design is performed at several frequencies and the results show a remarkable noise reduction.