Nonlinear analysis of thin-walled beams with highly deformable sections

Abstract

This work proposes an alternative approach for the nonlinear analysis of 2D, thin-walled lattice structures. The method makes use of the well-established Carrera Unified Formulation (CUF) for the implementation of high order 1D finite elements, which lay along the thickness direction. In this manner, the accuracy of the mathematical model does not depend on the finite element discretization and can be tuned by increasing the theory approximation order. In fact, the governing equations are invariant of the order of the structural model in CUF. Another advantage is that complex curved geometries can be considered with ease and without altering the nonlinear strain–displacement relations. After a preliminary assessment, attention is focussed on the nonlinear equilibrium analyses of U-shaped 2D lattice structures both in traction and compression. Also, a sensitivity analysis against the effect of various geometrical nonlinear terms is conducted. The results demonstrate the accuracy of the present method, as well as its computationally efficiency, giving confidence for future research in this direction.