Control of thermally induced vibrations using smart structures

Thermally induced vibrations of a smart beam are investigated. The smart beam refers to an aluminum structure with an integrated active control system consisting of piezoceramic sensors and actuators. A simply supported aluminum beam is used to illustrate the nature of thermally induced vibrations caused by a suddenly applied heat flux. A distributed piezoelectric sensor/actuator pair is used to actively suppress the motion caused by thermal disturbances. The effect of large temperature changes on the structure and actuator are taken into account in the control system design. An optimization routine is used to find a suitable placement for the sensor/actuator pair. Assuming full-state feedback, an LQR solution is obtained for vibration suppression. A classical control solution using PD feedback is also given. Simulation results show that thermally induced vibrations can be controlled using currently available smart structure technology, provided temperature effects are properly accounted for.