The vibration of structures is an important source of energy harvesting. Vibration analysis can be obtained through harmonic excitation. The piezoelectric structure can be used for the vibration to electrical energy conversion. The behavior of piezoelectric structures is extracted by the coupling of electrical and mechanical parameters. This model can be in the form of a flexible beam and plate, and can be used for large deformations. Large deformation and nonlinear material behavior can cause improper results when using linear theory. In this case nonlinear theory must be used. In order to study this model, the finite element method can be applied for the piezoelectric nonlinear beam and plate. Theoretical Results are verified by the experimental results. In the theory, Green-Lagrange strain-displacement equations are used for expressing the geometric nonlinearity. The motion equation is obtained from the Hamilton variational principle. Newmark technique and iteration method are applied for the dynamic analysis and nonlinear solution. The bimorph, multilayer piezoelectric beam with concentrated mass and plate are used in the numerical simulation and experimental implementation for the dynamics behavior verification due to the excitation of the harmonic load. The piezoelectric effect on the voltage, velocity and acceleration responses can be effective. The generated voltage and power depend on the type of connection layers, excitation load and resistive load in the resonance excitation. The resonance frequency depends on resistive load and amplitude of excitation load, and changes between the short-circuit and open-circuit resonance frequencies. The maximum power is obtained in the optimum load resistance with the corresponding resonance frequency. The variable boundary conditions and the separation method of electrodes in the piezoelectric plate affect the electric response and energy harvesting in the resonance excitation. According to the voltage cancelling phenomenon, the voltage output of the continuous electrode decreases comparative to the segmented electrodes. The maximum voltage value in the separated electrodes and the minimum voltage value in the continuous electrode are obtained for clamp boundary conditions in the piezoelectric plate. Keyword : Energy Harvesting, Beam, Plate, Piezoelectric, Multilayer, Geometrical nonlinear, Vibration, Experimental, Numerical Method.