D:\mkimball\ENAE651\main_00.DVI

A smart structure involves distributed actuators and sensors, and one or more microprocessors that analyze the responses from the sensors and use distributed-parameter control theory to command the actuators to apply localized strains. A smart structure has the capability to respond to a changing external environment (such as loads and shape change) as well as to a changing internal environment (such as damage or failure). Specifically, a smart structure incorporates smart material actuators. A smart material changes its characteristics (such as Young’s modulus, free strain, viscosity) under external field (such as electric, magnetic or thermal). Many types of actuators and sensors are being considered, such as piezoelectric materials, shape memory alloys, electrostrictive materials, magnetostrictive materials, electro-rheological fluids and fiber optics.