Electro-Mechanical Modeling of the Dynamics of Active Control Systems Based on anImpedance Approach

摘要

In this fundamental research program, the focus was to develop an understandingof the physics of actively controlled material systems, especially the power consumption and energy transfer mechanisms. A new impedance approach was further developed, giving particular attention to applications involving structures with impedance characteristics similar to aircraft structures. This newly developed impedance approach has an advantage over conventional approaches, such as the quasi-static and equivalent thermal force approaches, in that it includes the dynamic interaction between the structure and the actuator. A comprehensive impedance model for plate and shell structures was completed. By taking into account the dynamic interaction between the base structure and the induced strain actuator, the impedance model can accurately predict the dynamic response of the base structure. The electro-mechanical impedance model for plate structures was then extended to determine the power consumption and actuator conversion energy efficiency. This later extension of the impedance model allows the optimization of the actuator parameters based on power considerations. Also, the temperature rise and resulting thermal stresses, which can be significant at resonant frequencies, was investigated. Finally, the impedance approach was shown to be applicable to other types of actuators, namely magnetostrictive actuators and piezoelectric stack actuators.