Lightweight gauge steel combined section beams

The object of this study is beams made of lightweight thin-walled steel profiles of an open combined section with one axis of symmetry, consisting of three C-shaped profiles, under the action of a static transverse bending load without eccentricity. This work aims to identify the behavior of such beams when bending transversely and to substantiate the possibility of applying one of the methods of reducing cross sections for single profiles to calculation of beams of combines profiles. Method. An experimental study of bending behavior of a series of samples of such beams, which are hinged on both supports, under the action of a stepwise concentrated static load from a hydraulic jack is being conducted. Results. The deformation diagram obtained from the test results is compared with those calculated using various analytical and numerical methods. Based on the results obtained, it is shown that when bending transversely in the plane of symmetry beams of open combined section with one axis of symmetry work linearly up to 68% of the destructive load. It is proposed to use the method not considering reduction of the cross-section when calculating strength. It is proposed to use the methodology using the section reduction obtained according to the ARSS (Association for the Development of Steel Construction) manual when calculating stiffness. This method gives an error of 1.9%.