This paper investigates the effects of harvesting vibration energy to the electric power by a piezo-patch attached on a hinged-hinged elastic beam with experimental methods. Different harvesting effects of single and dual layer of the elastic beam are studied. This research also analyzes the optimal position of the piezo-patch under different concentrated force locations. We examine the harvesting effects of this system by using the Euler-Bernoulli beam equation and the piezo-patch electrical equation. These equations are used to verify the accuracy of the simulation and experimental results.