Approximate Evaluations of the Modal Effective Electromechanical Coupling Coefficient

Abstract

This contribution reviews and derives, in a unified manner using energy concepts, available formulas in the smart structures literature for the approximate evaluation of the modal effective electromechanical coupling coefficient (EMCC). A new approximate formula is then proposed; it has the advantage to use only short-circuit and open-circuit elastic properties of the piezoelectric patches, thus allowing the use of general-purpose structural finite element (FE) codes for the modal effective EMCC approximate evaluation. Besides, it avoids several usual assumptions (similar mode shapes, mass-less patches, etc.). An interpretation of the modal effective EMCC is also given using an analogy with the effective viscoelastic loss factor, allowing also the use of classical FE codes for the modal effective EMCC approximate evaluation.