OPTIMIZATION OF SHUNTED PIEZOELECTRIC PATCHES FOR VIBRATION REDUCTION OF COMPLEX STRUCTURES - APPLICATION TO A TURBOJET FANBLADE

摘要

This study presents three novel aspects. The first one is the use of an original FE model to solve the electromechanical problem of an industrial complex structure equipped with a piezoelectric patch. The second is the decomposition of the mechanical optimization in two steps in order to have a less expensive computation time. At last, it is the derivation of an analytic coupling indicator allowing to evaluate a huge number of patch design. rnThree main results have to be stressed. The first one is the optimization procedure for one patch can be done on a 3D mesh of around 105 dofs within a reasonable time (30 min) if some optimization algorithms are used. Then the MEMCF is very sensitive to the thickness of the patch, which is an often overlooked parameter in the optimization procedure. Finally, it was shown that the additional stiffness provided by the patch modifies significantly the optimal position found at the end of the first optimization step.rnThe future work is about the experimental validation of the FE model on the fan blade itself. This validation will be conducted for the free-free boundary conditions but also for the clamped-free to approach the mechanical operating conditions. Then, the natural extension of this work is to apply the optimization procedure to the case of several patches but new problems arise like, for instance, the definition of a relevant cost function.rnLastly, it is important to mention this method is applied here to a resonant shunt but remains valid for a resistive shunt or switch techniques since the mechanical and electrical optimizations are uncoupled.