Finite element characterization and parametric analysis of the nonlinear behaviour of an actual d 15 shear MFC

Nonlinear dependence between mechanical deformation and applied voltage has been experimentally observed on a recently manufactured lengthwise poled piezoelectric d ₁₅ shear macro-fibre composite (MFC) transducer. This work proposes a methodology to model this phenomenon by combining the nonlinear behaviour of the constituent piezoceramic fibre (electric field dependence of material properties) with a finite element homogenization technique to evaluate the resulting nonlinearity of the effective properties of the d ₁₅ MFC. Results show that the experimentally observed nonlinear behaviour of d ₁₅ MFC is reasonably well predicted by the proposed methodology indicating that this behaviour could be explained by an electric field dependence of the piezoceramic fibre material properties. Results also show that d ₁₅ and ${epsilon_{11}^T}$ coefficients of the d ₁₅ MFC are not significantly reduced by the MFC packaging, while e ₁₅ and G ₁₃ coefficients are reduced by 90 %, compared to the piezoceramic fibre ones. A conducted parametric analysis indicates that the actuation performance of the d ₁₅ MFC transducer could be improved by increasing the active layer thickness.