A composite beam model including variable warping effects derived from a generalized Saint Venant solution

•A model for beams with heterogeneous and anisotropic cross-section is presented.•Independent descriptions of displacement and stress fields are adopted.•They are obtained starting from a semi analytic solution based on a finite element discretization of the cross-section.•Nonuniform warping effects are considered in a simplified but effective way.•A mixed finite element has been used to validate the beam model.

A model for beams with heterogeneous and anisotropic cross-section is presented. A semi-analytical approach which exploits a FEM discretization of the cross-section is used to derive a Ritz–Galerkin approximation of the stress and displacement fields. In this way the Saint-Venant solution is easily generalized to generic composite sections and additional variable warping effects are also included in the model. Numerical results relative to composite beams with compact or thin walled section are presented and compared with full 3D analyses.