Ehsan Arshid - Department of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran;
Saeed Amir - Department of Solid Mechanics, Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran;
Mohammad Khorasani - Nanotechnology Engineering, Department of Basic and Applied Science for Engineering, Sapienza University, Rome,Italy;

Present article provides free vibration analysis of a micro three-layered beam. The core of the micro beam is made from FG porous materials and its faces are from piezoelectric materials. The properties of the porous core are varied functionally through its thickness following to three different patterns and the moisture effect is regarded. The Reddy’s third -order shear deformation theory is employed to derive the motion equations and the size effects are captured using MCST. Energy method and variational approach are used to extract the motion equations and Navier’s type is selected as the solution method for simply supported ends micro beam. The results are validated with the previously published ones and the effect of different parameters are considered and discussed in details. It is seen as the porosity coefficient increases, the natural frequencies reduce and comparing three types of pores’ distribution shows symmetric type has the most values of the results. The findings of this study can be used to design smart structures and systems.

Free vibration, Porous materials, Piezoelectric materials, MCST, Moisture effect.