Strengthening of Steel Beam by Inclined Stiffeners

Abstract

There are several ways how to increase the bending resistance of a beam. The simplest method is to increase the cross‐section size. But this method may not be the most efficient or feasible, especially in the case of an existing building in need of strengthening. In this paper, the method of strengthening a beam by welded inclined stiffeners is investigated. The beam is susceptible to lateral‐torsional buckling. A sensitivity study is prepared for the beam length and cross‐section size, boundary conditions, and the number and position of stiffeners. A validated numerical model using Component‐based Finite Element Method is used. The model combines shell elements for analyzed member and bar elements for related members. The joints are included in the model. Bolts and welds are simulated by special nonlinear elements with resistance based on codes. Validation and verification of the model is presented. It is based on the experiment performed at AdMaS center at Brno University of Technology of a beam with semi‐rigid joints loaded by three‐point bending. The model is verified by comparing critical buckling load and buckling resistances of columns and beams with clear boundary conditions. The results are also compared to those by another general finite element software, ANSYS and ABAQUS.