Co-rotational element of beam-column with springs for analysis of structures with semi-rigid connection

Abstract

In most steel structural designs, beam-to-column connections are considered either perfectly flexible or fully rigid. This assumption results in an inaccurate estimate of the mechanical behavior of frames. The formulation of a beam-column co-rotational finite element with zero-length springs at its ends is presented. This element is used to discretize two structural systems with semi-rigid connection and geometric nonlinear behavior. The system of nonlinear equations, which describes the structural problem, is solved with the incremental-iterative procedure of Potra-Pták associated with the Orthogonal Residue following-path. Computer simulations are performed with the open-source program Scilab. The numerical results obtained reveal that the alteration of the connection between structural elements from rigid to semi-rigid increases the flexibility of the structure and decreases its capacity to resist applied forces.