This study deals with the experimental characterization and the modelling of giant magnetostrictive materials and on their association with piezoelectric materials. An experimental benchmark dedicated to the survey of magneto-mechanics coupling has been achieved. This platform allows the creation in a bulk ferromagnetic sample of a homogeneous area of magnetic and mechanical sollicitations. An adapted instrumentation measures the magneto-mechanical response of the sample to these sollicitations. This experimenal benchmark has been used to characterise the behaviour of Terfenol-D samples, a giant magnetostrictive material. The gotten results show the very strong influence of the applied stress on the magnetic behaviour and on the magnetostriction strain of the material. A model of magneto-elastic coupling, based on the definition of thermodynamic coupling coeffcients, is proposed to describe the anhysteretic behaviour of the Terfenol-D. From the minimisation of funcional energy, finite element formulation of the magneto-elastic and electro-elastic problems are established. Specific considerations allow to establish finite element formulation of magneto-electric problem by coupling the two problems. Some applications are finally studied, especially magneto-electric composite structures associating magnetostrictive layers to piezoelectric layers. The survey of these composite structures shows the interest of a such association of active materials.
Modelling and characterisation of smart materials for the design of magneto-electric devices