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Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten. # Finite element characterization of d15 shear piezoelectric macro-fibre composites. Poled in longitudinal direction

Presentation held at ESMC 2012, 8th European Solid Mechanics Conference, 9th July - 13th July, 2012, Graz

Finite-Elemente-Charakterisierung von d15 piezoelektrischen Makrofaserverbunden mit Schereffekt und Polarisierung in Längsrichtung

**Abstract**

Macro-Fibre Composites (MFC) are well-known piezoceramic fibre based actuator and sensor modules which combine the energy density of piezoceramic materials with the flexibility and durability of epoxy. Mainly two kinds of MFC are commercially introduced to industrial applications: MFC with Interdigitated Electrodes (IDE) to induce longitudinal or d33 -mode in the fibres and MFC with netlike electrodes on top and bottom to impress an electric field in the thickness direction of the MFC and therefore using the transverse or d31 - mode in the fibres. Furthermore current research activities deal with monolithic shear actuated piezo patches, shear actuated piezo sandwich structures and also shear actuated MFC. In this work we now present the numerical characterization and determination of effective electromechanical material parameters of shear actuated MFC whose layout and dimensions are not only assumed but corresponds to the actual design of fabricable shear actuated MFC. Beside the dimensions the main difference to the previously assumed layout is the polarizing direction of the piezoceramic fibres. We consider longitudinal polarized fibers. This leads to a shear deformation of the longitudinal section of the fibres. During the examination of the concrete designs for the shear actuated MFC special considerations are made to deal with the correct incorporation of the electrodes and the electric passive layers of the MFC. The numerical characterization shows that the effective shear coupling factor k15 for the longitudinal polarized shear MFC is considerable higher than that for the transversal polarized ones. However, the model with the actual dimensions gives a considerable lower effective coupling factor than that for the assumed ones. This shows the potential for further practical improvements.