Direct stability analysis of steel beam-column with an elastic restraints

Abstract

The paper proposes the stability analysis of beam-column with an intermediate elastic restraint and arbitrary end conditions based upon direct analysis method. The proposal accounts for the second-order effects, geometrical imperfections, material nonlinearities and interaction of bending end compression. The material nonlinearity is implemented using the concept of multiple column curves. Furthermore, paper discusses the concept of equivalent imperfections based upon generalized imperfections factor and its application for the evaluation of the geometrical and material nonlinearities. The stability verification provided by the derived governing equations, discussed and compared with the numerical values obtained from the large displacement static analysis performed by means of the finite element method code, ANSYS. On the basis of comparative study several conclusions are drawn concerning the safety and accuracy of the verification of the stability by the proposed computational method.