Two-dimensional elasticity solutions for functionally graded beams resting on elastic foundations

Exact solutions for bending and free vibration of functionally graded beams resting on a Winkler-Pasternak elastic foundation are presented based on the two-dimensional theory of elasticity. The beam is assumed orthotropic at any point, while material properties varying exponentially along the thickness direction. The system of governing partial differential equations is reduced to an ordinary one about the thickness coordinate by expanding the state variables into an infinite trigonometric series. The problem is finally solved using the state space method, which is validated by comparing the present results to those available in the literature. Effects of several parameters, such as gradient index, aspect ratios, and foundation parameters on mechanical behavior of FGM beams are investigated. Numerical results are presented to serve as benchmarks for future analyses of such beams. (C) 2007 Elsevier Ltd. All rights reserved.