System identification techniques of smart structures with piezoelements

Analytical and numerical system identification (system ID) techniques of smart structures with piezoelements are introduced and compared in this paper. Simplicity and low cost of numerical system ID methods developed here make them beneficial in control design and implementation as well as in optimization of location and size of actuators and sensors of the smart structure. The accuracy of these techniques is then verified using analytical system ID, which derives the dynamic model of the structure from differential equations. In the first numerical system ID technique, Finite Element Method (FEM) is employed to model the dynamic system and to obtain the Frequency Response Function (FRF). Then a transfer function is fitted to the FRF plot using mu synthesis technique. Reducing order of FEM model, the other numerical method is developed, which depends on number and location of master nodes. The analytical FRF matches well with numerical simulations using FEM.