Multifield variational sectional analysis for composite blades based on generalized Timoshenko-Vlasov theory

Abstract

A multifield variational finite element (FE) cross-sectional analysis is developed following the Reissner’s partially mixed principle for composite blades. The three-dimensional (3D) displacements and crosssectional dominant stresses are considered to be the primary unknowns in the framework of the multifield principle. The cross-sectional warping deformations due to extensional, transverse shear, bending, and torsional loadings are incorporated. The boundary restraints due to nonuniform torsional warping are modeled to represent end effects for composite beams. The present formulation results in a generalized 7_7 Timoshenko-Vlasov sectional stiffness matrix including elastic couplings. Numerical results for the elastostatic response of composite beams and blades indicate good correlation with the available experimental data and other approaches. In addition, the stresses computed directly from the present multifield approach show an excellent correlation with the 3D FE solutions.