| Piezoelectric devices and electrorheological fluids are used to control structural vibrations of stiffened composite panels subjected to random loads. The surface-bonded piezoelectric devices first sense the strain-rate of the panel and then generate a localized control moment. The electrorheological fluid, located in the core of each sandwich-beam stiffener, alters the overall stiffness and damping properties of the structure in response to applied voltage. The transfer matrix method, modal analysis, and optimal control theory are used to determine the vibration response of the panel system. The relative effectiveness of the intelligent materials is investigated and collocated velocity feedback is compared to linear quadratic Gaussian control. |
