Vibration Control Of Rotating Electro-rheological Elastomers Sandwich Beams

Vibration control of rotating flexible beam is a hot research topic in IC equipment manufacturing industry. Active and passive vibration control method which applies intelligent material is an important research direction in it. Electro-rheological materials (ER materials), which play an important role in intelligent materials application, have developed a new branch called electro-rheological elastomers (ER elastomers). These ER elastomers which mixed polarized particles and elastic colloid are similar to rubbers; they can not only retain the capability of varying damping and stiffness of structures as ER fluids, but also solve the problems like unstable performance, particle sedimentation and leakage which obstruct the application of ER fluids for a long time. Thus, ER elastomers have more potential than ER fluids in engineering application. However, the reports about application of ER elastomers to vibration control of rotating flexible beam are limited.This research treats rotating ER elastomers sandwich beam as the study object. Firstly, the modeling, vibration control and experimental research of rotating flexible beams are introduced. Secondly, the dynamic model of rotating ER elastomers sandwich beam is developed based on first-order approximation couple modeling and finite element methods. Simulation analysis of the rotating sandwich beam in different external electric field and different rotation speed is employed. The results indicate that the increase of the external electric field can cause the increase of both modal natural frequency and loss factors of the rotating sandwich beam, which is good for vibration control. But if the rotation speed rises, the loss factors of the rotating sandwich beam will decrease, which is not good for vibration control. Vibration characteristic experiment of rotating sandwich beam shows that it is practicable to apply ER elastomers to vibration control of rotating sandwich beam. Thirdly, a hybrid control algorithm is proposed to control the vibration of the rotating sandwich beam which is divided into two subsystems-gross motion control and vibration control. The control method which combines an enhanced PD feedback with a nonlinear differentiator (ND) is used to control the gross motion of the beam, and a fuzzy method is used to control the vibration. Simulation results indicate that the enhanced PD feedback with a ND can meet the requirements of gross motion control and is better than ordinary PD control. It also demonstrates that fuzzy control behaves better than single electric field control under external interference. So the hybrid control algorithm proves to be effective. Finally, the experiment system is designed, and a point to point control of the rotating sandwich beam experiment is operated. Experiment results validate the gross motion control law and accumulate experience for the next study.