<title>Design of adaptive structures using compliant mechanisms</title>

Abstract

Static shape control of adaptive structures is currently an important and active research area in the smart structures field. Numerous actuation schemes using smart materials have been proposed and developed for shape control of structures. While the results of the smart material based technology is promising, it is also, however, showing more serious limitations such as scalability of laboratory-scale prototype models into real-scale models. In addition, the smart material based approach for shape control requires a multitude of actuators distributed throughout the host structure, the hence, complicates the control system. This paper introduces a novel alternative design concept for shape control of flexible adaptive structures using a single actuator which need not necessarily be smart material based. The novelty in this concept is that it employs distributed compliance in design--through compliant mechanisms, a class of mechanisms that transmit motion through inherent flexibility--rather than distributed actuation to accomplish the shape changes. The paper outlines a method for synthesis of such compliant mechanisms. The concept, and the synthesis method are illustrated through an example where a specified shape change in the leading edge of an airfoil structure is accomplished. The new concept has a great potential to not only eliminate the scalability problem, but also reduce the control complexity, the weight, and cost of the entire system as well.