A study for simultaneous optimization of a viscoelastic structure and active controller

Abstract

A formulation of simultaneous optimization a passively damped structure and active controller has been attempted. In this study, viscoelastic materials (VEMs) have been utilized as one of device to enhance damping passively. The formulation needs to adopt the modeling method that is capable of designing not only the viscous passive damping but also the active controller adequately. For such requirement, the time domain approach that results the accurate model on the time domain is employed for the modeling of the viscoelastic structures. In order to create the reduced order model (ROM) for system design, the complex modal analysis has been developed, and the ROM is obtained with using both truncation and the balanced realization method. The accuracy of the ROM has been investigated based on a cantilevered partially viscoelastic beam example. The numerical results indicate that the time domain approach is more appropriate than the modal strain energy (MSE) method for creation of the ROM. Moreover, the strategy to derive the ROM is included into the formulation of simultaneous optimization of a viscoelastic structure and active controller. The formulation is applied to the design of a sandwich beam like space structure. The optimization results indicate that the optimization of viscous passive damping is useful for the total system cost reduction.