Updated Lagrangian Formulation using ESA Approach inLarge Rotation Problems of Thin-WalledBeam-Type Structures

摘要

In this work a non-linear analysis of beam-type structures with a thin-walled crosssectionis presented. Using the updated Lagrangian incremental formulation, theassumption of isotropic and linear-elastic material behaviour and the non-lineardisplacement field of thin-walled cross-section based on inclusion of second orderterms of large rotations, elastic and geometric stiffness matrices of a two-node spacebeam element are developed. Due to the non-linear displacement field, all internalmoments occurring in the geometric stiffness are obtained as those of semitangentialbehaviour. In this way the joint equilibrium of non-collinear elements is provided.External stiffness approach is applied in the force recovery phase. The effectivenessof the presented numerical algorithm is validated through the test problem.