Multiphysic modeling of thin piezoelectric film made of polymeric nanofibers

Flexible piezoelectric devices made of polymeric materials are attractive for several tech- nological applications, most notably for mechanical energy harvesting and pressure/force sensors. Herein, a numerical approach is developed for multiscale and multiphysics modeling of piezoelectric materials made of aligned arrays of polymeric nanofibers. The microscale average response resulting from an homogenization procedure can be directly used as a multiphysics constitutive model at each quadrature point at the macroscale. At the microscale, the representative volume element consists in piezoelectric polymer fibers, assumed to feature a linear piezoelastic constitutive behavior and subjected to elec- tromechanical contact constraints. The latter are incorporated into the virtual work equations by for- mulating suitable electric, mechanical and coupling potentials and the constraints are enforced by using the penalty method. Consistent linearization is performed with the automatic differentiation technique, thereby preserving an asymptotically quadratic rate of convergence within the framework of implicit methods. The results shed light on the role of microscale geometry and constitutive variables on the performance of the material.