Formulation and implementation of three-dimensional doubly symmetric beam-column analyses with warping effects in OpenSees (No. R917)

Abstract

OpenSees is an object-oriented framework for finite element analysis. A key feature of OpenSees is the ability to integrate existing libraries and new components into the framework without the need to change the existing code. The non-linear beam-column element theory in OpenSees is based on the assumption that torsion is uniform through the length of the member and non-uniform warping torsion is excluded. In this report, a corotational mapping for three-dimensional analyses of doubly symmetric beam-column elements with warping effects is incorporated into OpenSees. Both a local linear strain assumption and a second order approximation of the Green-Lagrange strains are considered in the formulations of the beam elements at local level. Numerical examples are presented to demonstrate the accuracy of the proposed elements by comparisons with results from the literature and commercial softwares.