Fractional strain energy and its application to the free vibration analysis of a plate

Abstract

Fractional calculus is a branch of mathematical analysis that studies the differential operators of an arbitrary (real or complex) order and provides a new approach to non-local mechanics. In this study, a theoretical consideration on a new fractional non-local model is presented based on existence of fractional strain energy. It has two additional free parameters compared to classical local mechanics: (1) a fractional parameter which controls the strain gradient order in the strain energy relation and makes the model more flexible to describe physical phenomena, and (2) a non-local parameter to consider small scale effects in micron and sub-micron scales. The model has been used to obtain a fractional non-local plate theory. Free vibrations of a rectangular simply supported (S–S–S–S) plate has been investigated and the meaning of different parameters, such as fractional and non-local parameters, has been shown. The non-linear governing equation has been solved by the Galerkin method. A simple form of the governing equation and the numerical solution is an advantage of this fractional non-local model. Furthermore, the fractional nonlocal theory is contrasted with the Eringen nonlocal theory to show that fractional one enables to obtain much wider class of solutions.