<title>Incorporating finite element techniques to simplify the impedance modeling of active structures</title>

Abstract

An impedance model is formulated for the prediction of the response of structures to induced-strain actuation. The approach utilizes finite element analysis (FEA) to determine the host- structure mechanical impedance. The method couples the numerically obtained impedance to an analytical vibration solution of the induced-strain actuator to determine the dynamic response of the active structure. The methodology is demonstrated in the computation of the dynamic response of a beam structure to induced-strain actuation. This system has been extensively explored by the active structures community. Comparisons of the predicted dynamic response of this structure are made to the predictions of models previously documented in the literature. Experiments are conducted for the purpose of model validation, and an excellent agreement is demonstrated between the predictions of the FEA-based impedance model and measurements made on physical systems. It is anticipated that the formulation extends the FEA-based impedance modeling approach to a broader class of active structures, those for which closed-form expressions of host-structure mechanical impedance are non- existent. Use of the FEA-based impedance approach is suggested when modeling generic distributed structures possessing material anisotropy, mass loading, and non-uniform boundary conditions.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.