Size-dependent vibration analysis of the simply supported functionally graded porous material Al-Al2O3 rectangle microplates based on the modified couple stress theory with innovative consideration of neutral plane and scale distribution

PurposeHoping to uncover the physical principles of the vibration of the functionally graded material (FGM) microplate, by which the authors can make contributions to the design and manufacturing process in factories like micro-electro-mechanical system (MEMS) and other industries.Design/methodology/approachThe authors design a method by establishing a reasonable mathematical model of the physical microplate composed of a porous FGM.FindingsThe authors discover that the porosity, the distributions of porosity, the power law of the FGM and the length-to-thickness ratio all affect the natural frequency of the vibration of the microplate, but in different ways.Originality/valueOriginally proposed a model of the micro FGM plate considering the different distributions of the porosity and scale effect and analyzed the vibration frequency of it.