Vibration reduction of a turbojet fan blade with piezoelectric patches connected to a passive electrical circuit, commonly called "shunt", is addressed in this study. The purpose of this work is to present a method for maximizing the performance of a piezoelectric resonant shunt. The cases of resistive shunt [1] and switch techniques [2] are not covered here but the method remains valid. To improve the damping level, a key issue is the optimization of the whole system, in terms of location and size of the piezoelectric patches and electric circuit components choice. It was shown in [3] these two optimizations, mechanical and electrical, can be realized separately. Moreover, it is proved in [1,4-6] that the only parameters to maximize are the modal electromechanical coupling factors (MEMCF), which characterize the energy exchanges between the mechanical structure and the piezoelectric patches for a given mode. Since the optimal value of the electric circuit parameters are known as functions of the MEMCF and the system structural characteristics [3,7], they can be evaluated in a second step. Thus, the mechanical optimization consists in maximizing the MEMCF by optimizing the patches positions and dimensions, i.e. finding the best design. To fulfill this requirement and in order to manage a complex geometry, a 3D finite element (FE) formulation of the coupled electromechanical problem is derived [8]. A reduced order model of the discretized problem is then obtained by expanding the mechanical displacement unknowns vector onto the short-circuit eigenmodes to get the MEMCF.
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