Semi-analytical elasticity solutions for bi-directional functionally graded beams

Elasticity solutions are presented for bending and thermal deformations of functionally graded beams with various end conditions, using the state space-based differential quadrature method. The beams are assumed to be macroscopically isotropic, with Young's modulus varying exponentially along the thickness and longitudinal directions, while Poisson's ratio remaining constant. The state space method is adopted to obtain analytically the thickness variation of the elastic field and, when coupled with differential quadrature, the longitudinal discretization can be analyzed in an approximate manner. This approach is then validated by comparing the numerical results with the exact solutions for a special functionally graded beam and with finite element solutions. The influences of material gradient indices on the response of bi-directional functionally graded beams are finally investigated. (C) 2007 Elsevier Ltd. All rights reserved.