In recent years, space structures are expected to be larger for high performance. Additionally, they are required to be lightweight from the weight limitation in rocket launch, and lightweight materials such as CFRP are used in space structures. Large and lightweight space structures tend to be flexible, and the structures vibrate easily. Since vibrations are hard to decrease in the environment of high vacuum, they may degrade the performance of structures. Therefore, it is important to suppress these vibrations.
For vibration control, it is required to measure the vibration with high accuracy. It is general to analyze vibration problems of structures in modal coordinate space, and many researches have been performed on modal analysis. The modal sensors, which pick up only specified modes, are effective for vibration measurement, and many researches have been performed with beams and plates. In constructing the modal sensors, film type sensors such as PVDF are attached on the whole surface of structures, or the large number of point sensors are attached on structures. The modal actuators may be effective for vibration control based on the control theory such as the LQR theory. Many vibration control methods using modal sensors and actuators have been developed.
This paper presents a design method to construct the modal sensor and the modal actuator, and shows the vibration control of CFRP plates based on the modal sensors/actuators through numerical simulations and experiments.
edited by Arashi SAITO