ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

2aEA8. Optimum design for feedforward active structural acoustic control of complex structures.

Hector M. Rodriguez

Ricardo A. Burdisso

Chris R. Fuller

Vib. and Acoust. Lab., Dept. of Mech. Eng., Virginia Polytech. Inst. and State Univ., Blacksburg, VA 24061-0238

An efficient design formulation for feedforward active structural acoustic control systems for complex structures and disturbances is presented. The approach consists in a multilevel optimization procedure. The upper level part is carried out in the modal domain where the optimum modal control forces and modal error sensor components which minimize the total radiated power are obtained. These optimum model parameters are then used in the lower level optimization to obtain the physical characteristics of the transducers to be implemented. This separation between the modal domain and the physical domain during the design process allows the designer to investigate different control system configurations in the upper level part with minimum computational effort. The formulation is capable to handle the design of multiple-inputs, multiple-outputs control systems and multiple frequency excitations. The proposed approach is demonstrated for the case of a simply supported plate excited by a periodic point force. The first eight modes are included in the analysis. Several different control system configurations are investigated. The results show that the optimum configurations yield reductions in the total radiated power of up to 26 DB, depending in the number of control channels and the amount of allowed control effort. [Work supported by the Office of Naval Research.]