The system studied in this paper consists of thin structure with several piezoelectric patches bonded on its surface. The patches are used as actuators and sensors. Based on Kirchhoff-Love hypothesis, linear constitutive relations, plane stress formulation and Hamilton principle, we have developed a 2D model for this system using the finite element method. It is not a standard 2D model, since the calculation is performed on a structure that does not have symmetries that allow such easy assumptions. The originality of the work consists in the use of the concept of neutral plane to model this asymmetric system in 2D. This technique, beside good precision, saves computational time. An experimental device has been also built and tested to validate the model. The structural damping is included in the model to match the damping behavior of the real system. Optimizations of the thickness of piezoelectric patches and materials used in the thin structures are also presented in the paper.