Definition of warping modes within the context of a higher order thin-walled beam model

A procedure for the definition of uncoupled warping modes within the framework of a higher order beam model is presented. An approximation of the displacement field over the cross-section by a set of linearly independent basis functions is considered in the models formulation so as to capture 3D structural phenomena. By considering the cross-section in-plane rigid, a linear eigenvalue problem stemming from the models governing equations is derived, allowing to retrieve classic solutions and to derive a set of hierarchical warping modes. Numerical examples are presented in order to verify the ability of the model to simulate the warping of thin-walled structures.