A new finite element considering shear lag

Abstract

A new model of describing the shear lag phenomenon in composite thin-walled beams with arbitrary open or closed cross sections is defined. This phenomenon is unable to calculate using the classical theory of thin-walled beams based on the assumption that shear strains in the middle surface can be neglected. Therefore, this paper is based on facts presented in the papers of Prokic. He proposed the new warping function valid for both, open and closed cross sections and it does not require the assumption of neglecting shearing strains. The general approach to the solution of the problem is based on the finite element method. The principle of virtual displacements has been used to give a new linear stiffness matrix.